Architectu ~ith ~ RHEINZ~~ K®Roofing and

Wall Cladding

Zn - Revestimentos de Zineo , Loa. Rua Joaquim Oias Salg ueiro, 67 4470 -77 7 Vila No va da Tetha - MA lA Te lef. 22 998 33 40 - Fax 22 998 33 49 Move! 93 996 00 11 www .zn-revesl ime ntoS.pl

R EINZI K GMB D-45711 Datteln . Germany Telephone (02363) 605-0 Telex 829787 Telefax (02363) 605209

Translation of the 8th German Edition: "RHEINZINK® - Anwendung im Hochbau", January 1986.

Engli sh Issu e : Apr il, 1988

Rep roduction only w ith th e pe rmissio n of th e pu blis hers Publi shed by RHEINZINK GMBH , Datteln Printed by Graph. Betrieb Pli tt , Oberhausen

Table of contents

Preface Note

RHEINZI NK" 1.0 Buildi ng Material RHEINZINK® 1 1.1 Material Marking 1 1.2 Material Produ ction 1 1.3 Materi al Particulars 2 1.4 Material Properti es 2 1.5 RHEINZINK® Surface Finish 3 1.6 Catalogue of Components 4 1.7 Table of Weigh ts 8

Stresses 2.0 Stresses and Adjacent Effects 8 2.1 Rain and Snow 8 2.2 Wind Loads 8 2.3 Temperature Variations 8 2.4 Trapped Humidity and Moisture Yield 8 2.5 Combination with other Metals 9 2.6 Bituminous Co rrosion 9

Installation 3.0 Installation Instructions 10 Instructions 3.1 Forming 10 .

3.2 Working Temperatu res 10 3.3 Fixing 11 3.4 Joi nting 11 3.5 Soft Soldering 11 3.6 Calculation of Thermal Expansion 13 3.7 Therm al Expan sion - Comp ensation 13

Technical 4.0 RHEINZINKG Roof Coverin g and Wall Cladding 17 Terminology 4.1 Application Relative to Roof Pitch 17

4.2 Ventilated Roof Construction 17 4.3 Non-ventilated Roof Cons truction 19 4.4 Building Physics - Terminology 19 4.5 Sub structure 21 4.5.1 Roof Boards 21 4.5.2 Wood Chi pb oarding 21 4.5.3 Wall Boarding 22 4.6 Fixing Sheet Metal Roofing with

Regard to Wind Suction Forces 22 4.7 Numbe r and Spacing of Fixing s 23 4.8 Width s of Str ips and Thickn ess of Metal 23 4.9 Eaves Flash ings in Metal Roofing 24

Roof and Wall 5.0 Roof Covering using the Doubl e Standi ng Seam Met ho d 25 Details 5.1 Roll Cap System 30

5.2 Jo intings wi th RHEINZINK'" Roofing 32 5.3 Penet ration s in RHEINZINK® Roofing 36 5.4 Facade Cladd ing 41 5.5 Snow Guards 44 5.6 Lightning Prote ct ion 45

Weatherings 6.0 Weath erings and Flashings 46 & Flashings 6.1 Jointings 46

62 Weath erings and Flashings - Hard Roofing 46 , 6.5 Weath ering s 55

6.3 Flashings for Built -up Roofs 48 6.4 Eaves Flashi ngs 53 l

l

Roof Drainage 7.0 RHEINZINK-massiv Roof Drainage 58 7.1 Calculation 58 7.2 Jo inting 60 7.3 RHEINZINK-massiv Gutters 60 7.4 RHEINZINK-massiv Downpipes 62

Tooling 8.0 Tools for Sh eet Metal Roof ing and Wall Cladd ing 65 Profiling and Seaming Mach ines , Machines for Bend ing Seams 66

G e neral 9.0 Gene ral Directions for the Specificat ion of Items in 69 Instructions Sheet Metal Roofing Technique and Roofin g Contractor's Work 69

9.1 Notifying Reservations 69

Introductory Comments 10.0 Introductory Comments Regarding Quotations 69 Re garding Quotations

11.0 Practica l Examples 71

Legend 84

Notice 85

®RHEI ZI Processing and Application in Building

Preface Note The details and regulations forth e pro­cessi ng and appli cation of RHEIN­ZINK® in building referred to in thi s book should ensure compliance with minimum technical requirements. Ref­erence must also be made to DIN Standards, data sheets and prof es­sional specifications .

1.0 Building Material RHEINZINK" = alloyed zinc in ac cord­ance with DIN 17770, part 1, descr ibed as D-Zn bd ; D = creep resi stance, Zn =

zinc, bd = strip milled , and co nforming with BS 6561A.

1.1 Material Marking

DATIELN TITANIUM ZINC MADE IN GERMANY BS 6561 A - 0.70 Underside

1.2 Material Production As the only enterprise in the world, RHEINZINK possesses a continuous wide strip mill. By means of this techni­cally soph ist icated process of zinc roil­ing, long strips in specified thicknes­ses are produced from the patented RHEINZINK alloy in an un interrupted cycle (smelting, casting, rolling, coil­ing) , the following shearing operations cutting th e product into narrow strips or sheets.

(Con tinuous stri p marking)

The specially developed RHEINZINK rolling process and the exactly bal­anced RHEINZINK alloy guarantees highly uniform properties, the distin­guishing mark of RHEINZINK®.

RHEINZINK ~' strip and sheet are straightened on modern machinery and are thus technically plane and straight. This improvement in quality is of particular importance in facades and roof structuring, as it enhances ap­pearance.

Mel ting Casting Roll ing

. ~~ •• 0 i\ Ii •• ' ' . --­RHEINZINK semifinished product line

Sheet cu tti nc JIJ 0 0 ~

_ _ _.-.--- -- -- ---- - - - _ _ -. _ _ .__._ - - ------ -- - - ---- _ ._ -- _ .. - - - ­

1.3 Material Particulars Th e basis of the pa ten ted RHEINZINK a ll oy is electrolyt ic high grad e zinc (DIN 1706) with a 99 .995 %Z n degree of pu rity and alloyi ng add itives of copper and titanium . RHEINZINK®is a met al al­loy wh ich has bee n spec ially devel­oped fo r t he requirements of building co nst ruction.

1.4 Material - Properties Independently of the direction of rol­ling, RHEINZINf<® may be fo lded 180° w ithout tearing and may be folded back to its orig inal condi tion without break­ing. RHEINZINK®is d ist inguished by its h igh ductility with any kind of forma­t ion, including cold forming .

DIN 17770 Part 2 "St rip and Sheet Zinc in Bu ild ing Construction-Dimensions" specif ies variat ions from nom inal t hi c kness as ± 0.03 5 mm max .

Th e RHEINZINK(i, works standard per­mi ts a to lerance of ± 0.030 mm only.

? hysical Properties S pec ific density 7.15 q/crrr' Th erm al co nductivity 109

w m · K

Elect rical conduc tivity 17 rn/ Ornrn? Melt ing poi nt 4 18 °C Recrystallisat ion limit 30 0 °C Li near th ermal expan sion - longitudinal (Coeffici ent of ex pa nsion) 0.022 rnm/rn -C Min imum elasticity

1mod ulus 80,000 f-J i lTlrn:

Mechanical Properties (measured in longitud inal direct ion) in acco rdanc e with DIN 17 770

mini mum*) Exten sion coe fficient 0.2 limit Rp O.2 100 Tensile strength Rm 150 Breaking extension A lO 40 % Time creep limit (Creep res istance) for 1% expans ion/ p.a. - 0,/ 50 Brinell hardness 40 HB 1.25/2.5 /30 Vickers Hardness HV1 /15 40

Technological Properties Deep drawing limit rat io ~

D - Diameter of blank 1.6

d - Diameter of cupping punch Higher deep drawing limit ratio ~ for special alloys up to 1.9 Bend test number for bending radius 4 x metal thickness 10 Folding test - 180° with bend radius o at 20°C (± 2°) without tearing and bending up, without breaking

*) with material thickness up to 0.80 mm

Chemical Properties RHEINZINK®has good atmospheric re­sistance. First of all the zinc surface reacts with the oxygen from the air, forming zinc oxide. By the interaction of water (ra in , humid ity) zinc hydroxide is th en formed, which by reaction w ith ca rbon dioxi de in th e air is tran sformed into a den se, firmly adhe ring and water-insoluble coating of basic zinc carbonate (patina). Th is prot ect ive lay­er is responsible for the high corrosi on resistance of zinc.

Sulphur dioxid e, whi ch under unfa­vourable condit ions causes atmos­ph eric pollution , im pai rs the protective co at ing of the metal when there is a relat ive air humid ity over 70 %.

The protective layer, when worn or damaged, repairs itself by using zinc in relation lo lhe wear.

There are varying degrees of po llut ion in local atmospheres and thus varying intensity of atmosp heric corrosi on.

The tab le below shows average corro­sion rates, frequently published , for four different c riteria.

Q;<U 3.;:: ~ " aJ OTyp e of .2.. en ::J .§ t5 ~E ::JAtmo sp here ~ "' UaJU <1l ~ 0::J

:2: O N (j) .C:: Ea:

DIN 50960 2.2 3.5 11.4 8 .7 (ave raged)

Labo ratory Tests 2 .9") - - -Metallgese ll sc h.

E. Neufe r! 10.0 4.0 1.5 4.0 (averaged)

R. Pelzel 2 .0 2.5 8.0 9 .0

Rates of co rros ion of zinc , expose d to vario us c limatic influen ces: ave rage values from several sources, in mic rometres per annum (1micrometre = 0.001 mm).

The wid e range of rates of corrosion shown in th e tabl e may be explained by th e inexactly defined atmospheric cor­ros ion to wh ich the zinc surface is ex­posed; in an individual case no con­cr ete inform ation on the extent of the rate of corros ion which is to be expect­ed ca n be deduced from the table.

Th is would also explain the frequently expressed uncertainty by bu ild ing contractors, de signers and art isans when asked to assess zinc material for durability. Ne ither galvanised steel sheet with an average zinc platin g of 251-l , nor roof gutters of zinc sh eet are su itable examples for making suc h as­ses sments .

In orde r to obtain definitive find ings on th e actua l resistan ce to corrosio n of RHEINZINK(; mat eria l, RHEINZINK GM BH conducts me asurements of rna­ter ial th icknesses on work don e wi th the ir RHEINZINK" mate rial (al loyed zinc in ac cordance with DIN 17 770) us ing scie nt ific , ver ifiable methods.

It is atte mpte d to f ind the relat ions hip be tween geograp hic locat ion (emi s­sio n load ) and vary ing roo f pitch from flat pitch 3° up to vertical , i.e. facade c ladd ing and th e effect ive de pth of sur­face attac k.

2

Analysis of measurement data has al­ready shown that with increased pitch there is a decrease in the average rate of corrosion .

In the Ruhr region over a period of 14 years average surface wear values of approximate ly 4 IJm per annum have been found in respect of 3° roofs.When related to half-thi c kness values (= su r­face wear up to half of th e init ial mate­rial thickness) a durability of approx i­mately 80 - 100 years in respect of RHEINZINK®material can be expected in this emission zone.

In the vertical range, e. g. facade clad­ding, average corrosion rate in each case is below 2 urn/a. (even below 1 urn/a) according to our findings, so that when using RHEINZINK® for fa­cades , a maintenance-free life expec­tancy of some 200 years may be calcu­lated. This high life expectancy can of course only be achieved if the stan­dards relating to building physics are met and the material is laid according to the rules of the building plumbing trade .

As soon as the measurements have yielded sufficient reliable and verifiable data, RHEINZINK intends to publish the results.

In contrast with the behaviour of the RHEINZINK® surface exposed to the atmospheres different criteria apply in respect of the metal underside, l.e. the side not exposed to the atmosphere.

A basic zinc carbonate coating cannot develop here, as in this area the requi­site carbon dioxide from the air is lack­ing. There is no interchange of air . The metal remains shiny, or some zinc hy­droxide may develop (white rust) which is of no consequence.

Where, however, as a result of co n­structional or installational defects, the metal underside suffers damp or con­densation over a longer period of time , heavy condensation corrosion must be expected. Thi s typ e of condensation corrosion will eventually lead to lo­calised depth corrosion (pitting) .

Toavoid these eventualities, adequate ventil ation of th e substructure must be

prov ide d. Depending on vapour diffu ­sion load, either a damp course (va­pour barrie r) or insulation must be installed. The substructure should be also wind-tight. (2.4 Complementary information - see Guidelines, Roofing Trade).

Further RHEINZINK® specific data

Fire-resistant properti es Non-flammable, building material CI. A

Damp-resistant prope rties Frost -resistant, water repell ant sur­face, damp-resistant, vapour-r esistant

Stability UV-resistant, rot proof, will not break, recyclable

Painting Owing to the natural protective coating (patina) of basic zinc carbonate, additi­onal protective painting under normal environmental influences is not re­quired with RHEINZINK®.

If subjected to extreme environmental influences or for visual reasons, paint­ing (coating), after natural weathering or degreasing of bright surface, may be proceeded with following suitable priming .

For surface cleaning the use of organic solvents is advised (these must be clean so as not to contaminate the sur­face with fresh grease). This will pro ­vide a good ground for the base paint.

Attention is also drawn to the "Guide­lines for the execution of metal roofs, wall cladding and plumbing work" (Sept. 1985 edition).

1.5 RHEINZ N~ Surface Finish RHEINZIN~ Bright rolled finish RHEINZINK and components made therefrom are supplied in br ight rolled fini sh. On expo sure to th e atmosphere, the patina referred to above develops. This blue-grey patina harmonizes well with the natural colours of other build­ing materials, such as concrete , brick and wood.

Afte r laying , undulat ions caus ed by rol­ling show up on RHEINZINK® bright rolled finish, as with other rolled metals such as copper and aluminium. The undulations are revealed by the reflec­tion of light, but it is difficult to measure them mechanically. Even in th e bright roll ed finish, th ese undulations, so st rongly emphasised visually , will dis ­appear if one changes the direction of view (with a change in focal point and therefore th e angle of reflection) (see illustrat ion) . As soon as the protecti ve coating begins to develop on the RHEINZINK® surface, then strong ref­lections can no longer app ear and the slight undulations will no longer be vis­ible; nor will they be visibl e on an artif i­c ially pat inated surface.

RHEINZ INI(® "preweathered" The formation of a typical RHEINZINK patina takes a long time , depending on the season and prevailing climatic and environmental conditions.

A special process, developed by RHEINZINK, - preweathering - gives the surface patina a natural appear­ance from th e start.

"Preweathered" RHEINZINK® is pro­cessed exactly like RHEINZINK br ight rolled .

"Preweathered" RHEINZINK'" is parti­cularly suitable for the visible areas of roofs and walls. For thi s reason, prepa­ration should proceed carefully and cleanly, particularly ensuring there is no grease on the fold ing machine.

3

I 1.6 Catalogue of Components

RHEINZ INK® Semis

Strip max. width 1,000 mm Sheet 1,000 x 2,000 mm Thickness 1.50100 0.800.700.650.60 mm

Special sizes on request

RHEINZINK-n1Iossiv

Finished products (se lection)

. - -- .

4

Roofing Profiles For the installation and fixing of these produ cts the reco gnised co de s of practice must be fol­lowed (VOS and DIN).

All specia l p ro f iles in le ngths of 2-6 metres can be made on el ectronic bending mach ine s at ou r sales depots upon requ est.

Stand ard length : 3 m

Eaves Flashings These must adeq uately cover the timber board of the roo f area. The lap ping of the flash ing by th e roo f co vering is depend ent on roof pitc h, the roofing material and the c limatic (local) co nd itions prevail ing.

Standard sections

c ut widt h

mm

a

mm

b

mm

c

mm

d

mm

min. thickness

mm

P;:"ca V­

, I > 250

250 200 167

10 10 10

17 17 17

217 167 134

0.80 0.70 0.70 0.70

~

~CO ~

< !

I., W

> 250 250 200 167

10 10 10

17 17 17

198 148 115

15 15 15

0.80 0.70 0.70 0.70

I

~[t ~

c

I 400 333 28 5 250 200 167

15 15 15 15 15 15

50 50 50 50 50 50

335 268 220 185 135 102

0.80 0.80 0.70 0.70 0.70 0.70

I ~[t

V

e

I.., W

400 333 285 250 200 167

15 15 15 15 15 15

50 50 50 50 50 50

3 18 250 202 168 118 85

15 15 15 15 15 15

0.80 0.80 0.70 0.70 0.70 0.70

6 1

~ I > 250

250 200 167

15 15 15

25 25 25

208 158 127

0.80 0.70 0.70 0.70

6 1

~

c

I., W

> 250 250 200 167

15 15 15

25 25 25

190 140 112

I 15 15 15

0.80 0.70 0.70 0.70

Valley Gutters min. thickness 0.70 mm

cu t w idth a b c d e

Stand ard sec t io ns mm mm mm mm mm mm

~ l~ ~)

'v' 1~\

V''''-../

667 500 400 333

667 500 400 333

667 500 400 333

500

15 15 15 15

15 15 15 15

15

333 250 200 166

334 250 200 125

31 5 232 182 193

315 23 2 182 148

132 50 50

5

Cappi ng Strips min. th ickness 0.70 mm

S tan dard se ctions

~

~] L :>

V

<1:j1 'C " . y

Ll ~

cut width

mm

a

mm

b

mm

c

mm

d

mm

e

mm

100 89

100 89

100 83

8 8

8 8

10 10

20 20

20 20

20 20

44 33

44 33

60 43

20 20

20 20

10 10

8 8

8 8

Angle Strips (wall abutment) min. thickness 0.70 mm

lL i c II {l!d

I c I

333 285 250 250 250 200

400 333 250 200

15 15 15 15

208 160 150 125 150 100

200 166 125 100

125 125 100 125 100 100

183 150 108

83

Kerb Weath erings·/Verge Flashings min thickn ess 0.70 mm cut width a b c d e f 9

Standard sectio ns mm mm mm mm mm mm mm mm

-r~t < 1 ~ ' ?!

/i ~ · i ~~ -IG , L'J L..::: '-:j'

,

-rL~ ,1

333 285 250

333 285

333 285 250 200

15 15 15

15 15

15 15 15 15

20 20 20

20 20

100 100 80 60

160 105 80

105 80

168 120 120 100

25 25 25

25 25

50 50 35 25

128 135 125

158 135

15 15

22 22 22

22 22

43 43 30 22

T~ ·1 W,;r 333 285 250 200

15 15 15 15

100 100 80 60

155 102 102 87

50 50 35 25

13 13 13 13

43 43 30 22

'- '--'

~ ~ I ~. ) - ; ? L ,1­

333 285 250 200

15 15 15 15

30 30 30 25

80 50 40 30

50 40 30 20

108 110 105

90

40 32 24 16

6

Standard sec tions

"~I ~> u J _ ~

. I\~ . ~ I

"L ,; >..

~ -_.~

I.., " ~; L.J ~

Gravel Boards

cu t widthl size mm

a

mm

b

mm

c

mm

d

Imm

e

mm

I

mm

g

mm

333 15 30 80 50 92 13 ~ O

285 15 30 50 40 94 13 32 250 15 30 40 30 89 13 24 200 15 25 30 20 75 13 16

333 15 100 50 60 108 285 15 80 35 50 105 250 15 70 30 40 95 200 15 50 20 20 95

333 15 100 ,50 60 92 13 285 15 80 '35 50 90 13 250 15 70 '30 40 80 13 200 15 50 20 20 80 13

min. th ickn ess 0.70 mm

min. thickness 0.70 mm

cu t widthl a b c d e size

Standard sec t ions mm mm mm mm mm mm

167 15 68 58 125 15 48 40

Parapet Weatherings min. thickness')

n. A. = as

ord ered

n. A.

n. A.

15

15

15

n. A.

n. A.

n. A.

n. A. n. A. n. A.

n. A. n. A. n. A.

n. A.

• Mini mum gauge lo r weath erings 167 mm = 0.65 mm, up to 333 mm = 0.70 mm, up to 400 = 0.80 mm and up to 60 0 mm = 1.00 mm. Wind ow Sill Weatherings

7

1.7 Table of Weights RHE INZINK®in ac cordance with DIN 17770 D-Zn bd in kg/100 m, Density ~ 7.2 (Weights = Approximate values)

Thickness mm

Cutmm 1.20 1.00 0.80 0.70 0.65 0.60

1000 I 864.00 720.00 576 .00 504.00 468.00 432.00 800 690.00 576.00 460.00 403 .20 37 4. 30 345 .60 66 7 576.00 480.00 38 4 .00 336 .00 31 2.00 288.00 500 432 .00 360.00 288.00 252.00 23 4.00 2 16 .00 400 345.60 288.00 23 0 .40 201 .60 187.20 172 .80 333 239.76 192.00 168.00 156.00 144.00 285 164.1 6 143.64 133.38 123. 12 265 152 .64 133.56 124 .02 114.48 250 144 .00 126.00 11 7.00 108.00 200 115.20 100.80 93 .60 86 .40 167 84.00 78.00 72 .00

rigid materials these longitudinal chan ges are c learly effected by tempe­raturevariatio ns.Therefore RHEINZINK bu ild ing co mpo nents must be able to expand and contract eas ily at a tempe ­ratu re diff erence of 100 K, without be­coming permeab le. Tocomply wit h this requi rement, only indirect fastening by means of sliding c lips , strip s and notch ed battens is allowed , apart from the anc horage po ints in the neut ral area. The longitudinal movement s mu st be ba lance d out by means of ex­pan sion jo ints (3.6 and 3.7).

2.0 Stresses and Adjacent Effects Any exposure to st resses and harmfu l eff ects from other materials must be av oided by taking appro priate preven­tive steps.

2.1 Rain and Snow Claddings and covering s of RHEIN­ZIN Kt

.' must be rain and snow proof . Bas ic cons ideratio ns are th e maximum valu es of local rainf all -->- 7.0 and maxi­mum snow load (DIN 1055, part 5).

The necessary constructional mea­sures are described in sect ions 3.4,3.5 and 6.0 and are illu strated in the corre­spond ing sections .

~ tJ

2.2 Wind Loads Wind suction and bac kpressu reforces must be tran sferred to the sub st ruc­ture by means of correctly dim en­sio ned fixings (DIN 1055, part 4). Sp e­cia l attentio n must be paid to areas suc h as roof edges or corners.The fas ­teners or fixings to be used are c lips, slidi ng clips or strips . The number and nature of fixing eleme nts for th e sub­st ructure are specified in sections 3.3, 4.6 and 4.7.

2.3 Temperature Variations With variat ion in temperature all mat e­rials are subj ect to longitudinal cha nges, acc ordi ng to th eir speci fic coefficient of expa ns ion. In the case of

Variat ion s in temperature : seasona l. time of day

2.4 Trapped Humidity and Moisture Yield RHEINZINK®has, as have other metals, to be protected on the unde rsid e by means of bituminou s roofing felt or non-porous lin ing : - aga inst alkaline influence, e.g. ­

fresh concrete or mortar, - against acid reacting antif reeze

agents, - aga inst th e harmful influence of

wood preservatives.

Ice, snow. rain Wi nd. suction and back p ressure Moistu re yie ld . trap ped humidity

8

Avoid conde nsation on the inside of the zinc since such condensation can cause "white rust" corrosion. With double leaf roof co nstruct ion, th e moisture is carried away by the ventil a­tion spaces provided und erneath the roof covering .

With single leaf roof construct ion, both the insul ation material and th e cover­ing have to be protected by a vapour barrie r and the moisture dispersed through the porous diffusion layers. Single leaf roof constr uction is not nor­mal for sheet metal cov ering and should be avoided.

Doubl e leaf roof cons truction should be adopted in every cas e wh erever practicable, so that air has free access to both sides of the zinc. By this means, condensation on the undersid e of the metal is prevented.

2.5 Combination with other materials In th e presence of an electrolyte (rain­water, condensation , etc .) there is a danger of electro-chemical corrosion (formation of voltaic couple). However, this hazard is often over-estimated and can be met with confidence, so long as only the metals marked with the sym­bol + are used in combination.

AI Pb Cu NRS St

RHEINZINK'" + + + + AI Alu mini um Pb = Lead Cu = Coppe r NRS = Stain less steel St Galvani sed stee l

Where several different metals are to be employ ed on a bui ld ing structure, the follow ing rule must be observed : In the direct ion of rainwater flow the metal with the highest normal potential must be arranged at the lowest point.

In the construction of bu ildings there is frequently direct contact between zinc and aluminium . Examp les are : Facade cladding of zinc , windows of alum in­ium, roofing of zinc, window sills of alu­minium, roof gutt ering of zinc, facad e cladding of aluminium.

The combination of these metals is basically possible wit ho ut danger of

contact corrosion. The reasons are as follows:

Since in normal atmospheric condi­tions th e surfaces of both metals are not in metallic form but covered with a natural protective coating, which in the cas e of aluminium is ofte n reinforced by anodising, apa rt from th e actual lay­ing stage, meta llic contact between aluminium and zinc can almost be ruled out. With zinc, th e natural protec­tive coating consists of an oxid e/ car­bonate layer and with aluminium, of aluminium oxide.

Both coatings adhere firmly tothe base metal and protect it permanently against corrosive damage. Corrosive resistance is betw een pH 6 and pH 12.5 for zinc and pH 4.5 and pH 8.5 for alu­min ium. Both coatings are self-h ealing, i.e. following mech anical damage, they reform. When evaluating contact cor­rosion between alum inium and zinc ex­posed to th e atmosphere , th e estimate must be based on the inert surfaces re­ferred to . As both inert surfaces have very similar potential (approx. -170 mV in aluminium and approx. -200 mV in zinc), corrosive destruction in normal atmospheric conditions can be ruled out. This can only occur with metals whose potentials are spaced far apart, e.g. 400 mV (silve r - zinc) .

These theoretica l considerations have been confirmed in practice and have been documented in many technical publications (Prof. Dr. C. A. Witt "The co rrosion behaviour of aluminium in contact with zinc in building con stru c­t ion ").

Please note: In practice , it is unfortunately often ob­served that galvanised ste el construc­tion s above RHEINZINK® dra ining sur­fac es - pr imar ily roofing - lead to dis­figu ring rust-b rown dra inage str eak­ing.Such rust usually forms very rapid­ly at the unprotected cut edges of gal ­van ised stee l com ponents. This un­sight ly discolouring, wh ich impa irs the overall appearanc e of a bu ild ing, can be best avoided by employ ing chrom e­nic kel ste el const ruct ions.

2.6 Bituminous Corrosion Bitumen can also corrode zinc. Th is has been known for over 50 years (Bib­liograph y VEDAG Year book 1936/R. Deis , page s 123/135 ). More rec ent work by Prof. Witt ("Oxidation acid co r­rosion du e to roofing bitum en", Mate­rials and Corrosion, Issue 1/1980, and "Corrosion beh aviou r of Zinc",vol. 4 11 ­The prop erties of zinc in combi nat ion with bituminous materials, by Prof. Witt , publisher: Zinkberatung e.V. Dussel­dorf; Unte rsuchung der Bundesanstalt fOr Materlalprutunq (BAM). ''The influ­ence of bituminous roofing materials on the corrosion properties of roof drainage systems of zinc and galva­nised steel") has not only confirm ed th ese find ings, but augmented and ex­pand ed essentia l po ints. Our own in­tensive laboratory test s and practical experience show the same results. This research has been incorporated into the technology and is explained briefly as follows:

Bitum inous co rrosion is caused by the waste products of bitum en,which form due to the influence of ultraviol et rays. These strongly acidic waste products are water-soluble and in small quanti­ties of atmospheric wat er (dew/fog) form conce ntra ted acid which general­ly attacks metals.

If, co ntrary to the rules, bitumen re­mai ns without an effective shield (e.g. grav el chipp ings 5 cm ) all metals, such as wall abutments, eaves flashing and gutters situated in the area of roof drainage, must be additionally prot ect ­ed with a dense mat erial. In resp ect of RHEINZINK cold bitumen and hot bitu­men with a primer are suitable.

Exceptional expos ure can also be ex­pect ed whe re th e gutters and pip es of old (e.g. moss-covere o) roof ti ies need replac ing. In such cas es where there is drippi ng into the guttering from con­cave ti les, corrosion may occ ur,as dur­ing the course of ageing the tiles have accumulated harmfu l material s from the atmosphere and di scharg e these in th e fo rm of weak ac id (e.g. in combi­nation with S02) when there is drizzle or fog . Depend ing on the time of year when th e new guttering is insta lled, of­

9

tEn th ere has not bee n suffi ci ent time In thi s and simtla r cas es spec ial co at­fo r th e developm ent of the prot ect ive ings should be ernploye o. The follow­coating in the areas particul arl y at risk, ing easy-to-hand le mate rials are cur­

rent ly availab!e :

1. Protection against bituminous corrosion:

1 .1 Intertol 49 W Lechl er Che mie, Stuttgart 1 .2 Plasti kol 2 (AlB) or Hydrolan FS'2 Deitemlann Chemi e, Datteln 1.3 Isopunkt Ges ellschaft fur c hem. Pm dukte mbH, \IIlissen

2 . Protection against acid atmosphere

Here, basically co at ings which do not contain bitumen, should be used ,

2 .1 Zinc powder colours of various manufacturers 2 .2 Tegocolor PVC' Th . Goldschmidt AG, Essen 2 .3 Lubroplast PVC-Mixed polymerisat e co ating Industrielac k GmbH , Stadt Allendorf 2 .4 Deltafle x-Iacqu er paints Ewald Darken AG, Herdecke/Ruhr 2 .5 L-Coating-Deck 458 or BUFA-Asbit 455 Busing & Fasch KG, Oldenburg 2.6 Osopren hi ' t d bb ' t Lackschmidt, Hamburg2 .7 Vernolan c onna e ru er pain s Pietzker, Hamburg 2 .8 Further manufacturers of prot ect ive paints see data she et "Techn. Mittei lung K9" published by Zinkberatung,

The paints can be applied to the zinc newed at regular intervals. Depending 2.6.1 surface without primer if the surfaces on exposure, repainting should take Chlorinated rubber paints are clean, dry and particul arly oil- and place every 2 to 3 years. Chlorinated rubber paints have proved grease-free. If a film of oil has to be re­ themselves well in practice as res ist­moved, an alkaline degreaser must be Numerous protective paint products ant, easily applied protective coatings,used (Chem etall, Frankfu rt , Bonder are offered on the market. Their effect­ also against possible corrosion from Dept.), iveness as a protective coat ing must be bitumen. Applications of large areas of

verified in every case.The manufactur­ bituminous coatings, exposed without The coating material must be densely ers ' instruct ions must be strictly fol­ protection to UV radiation can , on the ap plied. Such protective coatings lowed. other hand, cause bituminous corro­must be regarded as routine mainte­ sion in following , unprotected flow sys­nance, as they are exposed to natural Important: tems (e.g. rain-water pipes) . corrosion and ageing and must be re- Bituminous emulsion sealing coatings

are unsuitable for use as protective coatings on zinc since owing to their high alkalinity they have a corrosive ef­fect.

Installation Instructions Anisotropism, the different properties across and in the direc tion of rolling, has been so reduced in the fin ely grained structure of RHEINZINK® that no not ice need be taken . Thus RHEIN­ZINK® is formable independent of the d irect ion of rolli ng,

3.1 Forming Rounding, bending, folding, flanging, sea mi ng and double seaming repres­ent the forming methods in the proces­sing of RHEINZINK.®This work can be easily carried out with conventional tools and equipment.

For bending, a roun d bar with a ben din g radius of 1,75 mm should be used, In ac c ordance with the code of practi ce sha rp instrum ents sho uld no t be used (notching).

3.2 Working Temperatures Uniform forming procedures at over 10°C (metal temperature) are no prob­lem. For formation by impact or at lower temperatures, preheating is advised to counter the possibil ity of cracking due to cold br ittl en ess of zin c .

3.0

10

3.3 Fixing

.>/

.. ---------­Standard c lip

o

Clipp ing strip

For d irect fixing, partic ularly of c leats, fix ing st rips, etc., galvani sed steel nails (flat head tack s 2.8/ 25 mm) must be used. The tacks must penetrate to a minimum depth of 20 mm into the roof boards . For ind irect fixing of roof cover­ing, weatherings, etc ., cleats, sliding c lips, continuous strips, toothed con­nection plates or fixing plate s should be used. The indi rect fixing of building com ponents - exc lusive of anchorage points - is obligatory (VOB) to allow unhindered th erm al expans ion caused by thermal influences.

3.4 Jointing All joints between the individual build­ing components must be rain - and snow-proof.This also applies to expan­sion joints (3.7).

This requ irement is complied with by soldering , double seaming, seam ing and in the expansion area by the RHEINZINK expansion compensator, or other constructional means, in ac­cordance with the roof covering con­cerned .

In some regions riveted jo ints instead of soldered joints are used. The rivets are cold punched. Due to this cold ri­veting the friction force between the components to be jointed will not be transferred. The rivets are st ressed by shearing strain and th e jointed part s by bearing strength.

Aluminium alloy rivets are norm ally used (no contact corrosion).

In general th e flush riveting process is employed, as this allows multi -side rivetin g with out backing.

3.5 Soft Soldering of RHEINZINK® The remarkable advantage of RHEIN­ZINK® is its easy solderability. By simple soft soldering a secure, water­tight joint is produced.

Solder Lead-tin soft solder with 40% tin, low antimony (Sb) in accordance with DIN 1707, for alloyed zinc .

Marking Solder st ick: DIN 1707-L-Pb-Sn 40 (Sb ). Exact marking on 25 kg lots only.

Flux Flux in accordance with DIN 8511, part 2, Type F-SW11.

Marking RHEINZINK Flux Z-04-S

Technica l Instructions ­Soldering Surface Basically the surface of the area to be soldered must be bright. If unclean, soldering will be difficult and the joint­ing incomplete.

Flux To soft-solder RHEINZIN~, RHEIN­ZINK Z-04-5 flu x should be used . This flu x ensures adequate cleaning of the visual metal surface, optimal flow and adequate protection against oxidation. Nowadays, hydrochloric ac id is no lon­ger recommended, as the optimum c leaning and flowing eff ects cannot be ach ieved. After so ldering residual flux can be removed with a damp rag.

Soft solder Lead-tin soft solder with 40% tin in ac­cordance with DIN 1707-L-Pb-Sn 40 (Sb) is recommended. This solder has max imum filling ability, good flow pro­perties and high strength. The melting ran ge of thi s so lde r is betw een 183°C and 235°C. With a required working temperature of about 250°C coarse grain development (embritt lement) will not arise,and thu s there will be no dimi­nution of st rength .

Low ant imony solder is prescribed for RHEINZINK:'. The letters in brack ets (Sb) de scribe th e low ant imony solder.

Solders containing a high proportion of impurities have very negative proper­ties, parti cu lar ly with an antimony con­tent in exc ess of 0.5 %. A higher anti ­mony con tent result s in coarse alloys of high melting temperature, which apart from everything else affects capillarity and th e flow of th e solder . Even at room temperature segregation

11

takes place (recrystallisat ion), i.e. em brittlement of the cast structure (p rematureageing).The strength of the soldered joint may be reduced to 50 % of the original st reng th.

Soldering irons Soldering (hamm er) irons with a mini­mum weight of 350 g ensure an ade­quat e capacity for heat, without th e danger of over-heat ing. A broad con­ta ct area is essential for rapid and constant heat transfer to the joi nt. Care must be taken to ensure that the heat is applied to the overlap and not to the joint.

Ca re of soldering irons From time to time the copper bit must be reforged to maintain its good ther­mal conductive property and correct shape. The lateral flat surfaces and fins are smoothed off by filing.

Before soldering is begun the area to be treated must be cleaned free of ox ide by tinning. The bit, which has been brought to working temperature, is moved back and forth in powdered sa! ammoniac, at the same time touch­ing the surface with tin solder. Thecon­tact surfaces are thus tinned.

RHEINZINK® bright finish: No spec ial preparat ion, as RHEIN­ZINK® is roll ed with a sp ecial low oil emulsion.

RHEINZ INK"" oxidised: Thick layers of oxide or dirt to be re­moved mechanically by scraping or app lyi ng emery paper.

Soldering joint overlap The joint overlap should have a mini­mum width of 10 mm, as the bonded joint width must be 10 mm in the hori­zontal area (DIN 18339), (i.e. in the slightly inc lined area), and 5 mm in the vertical area (DIN 18461).

Solder-penetrated joints, i.e. overlap width = bonded width of soldered joint, give the greatest degree of strength; on the other hand a larger width of overlap does not give the jo int increased strength , since penetration is difficult, if not impossible.

Pre-tinning When soldering large building compo­nents, as well as materials thicker than 0.80 mm (e.g. shed roof gutters) pre­tinning of the joint areas is recom­mended, as dressing of the joint to a

The correctly dimensioned co pper bit for the soft soldering of RHEINZINK"'.

measureme nt of 0.5 mm or below causes technical problems. Pre-ti n­ning br ings about better adhesion.

Joint thickness The thic kness of th e jo int must not ex­ce ed 0.5 mm in order to achieve maxi­mum capillary filling. Due to diffusion in the contact areas alloying takes place, an essential factor in determining the st rengt h of the bonding. In thi cker jo ints a coarsel y porou s st ructure would occur in the seam instead of the penetrating alloying layer but with an inferior strength of solder

There is no recrystallisation with RHEINZINK c at temperatures below 300°C, which means there is no prob­lem of overheating during soldering. Not only this, but RHEINZINK' is ac­tually tempered by the heat treatment from soldering.

Drop seams (dripping) are wasteful of solder, as they do not increase the strength of the seam: only the solder in the joint effects a bond. (see RHEINZINK® working procedure for soft soldering)

< ,

N

I "---f-H--

,

.~ Soldering iron > 35 0 g

o o

---1 8

= 10 mm fo r horizon ta l so lde ring seam

= 5 mm fo r vertica l sold ering seam

:ii!::!::!"1

10-[ 5

J ~26

10

i ..

12

3.6 3.7 Calculation Thermal Expansion of Thermal Expansion Compensation

Material Coeffi c ie nt

of expansio n K- 1

Material Coe ffi c ient

of expansion K- 1

Aluminiu m 0.00002 4 PVC 0.00008 0 Constructional S teel 0.0000 12 Qu artz Glass 0.0000005 Lead 0.000029 Silver 0.000020 Bronze 0.00 0018 RHEINZINK" 0.000 022 Cast Iro n 0.0000 104 Z inc 0.000036 Copper 0.00 0017 Concr ete 0.000012 Brass 0.000 019 Tin 0.0000 23 Nickel 0.00001 3 Bric kwork 0.000005

Linear coeff ic ient of th ermal expansion between 20°C and 100°C for various materials.

All mate rials undergo lon gitudi nal movement at variations of temperature. The change in length IJ. I is calculated from the product of the initial length 1 ,

0 the materi al constant coefficient of expansion a and th e temperature IJ. t =

(1 - t .). 2

Thus we have the formula:

Change in length IJ. I = I a (t - t ) = 021

1 a . IJ. t 0

· . I . m : m DImenslona equati on : m = --- . K

m K

In accordance with the generally ac­knowledged technica l rules (VOB and Guidelin es for faca des) a temperature variation of 100 K is calc ulated for roof and wall areas . In this it is assumed that inwinter temperat ures of - 20 °C and in summer + 80°C are reached.

In accordance with this : With an ass umed working temperature of 15°C (met al temperature), 65°C act on expansion and 35 °C on contraction of the material.

The linear expansion of RHEINZINK®is 0.000022 rn/( mK). For a leng th of 6 m the following example is given :

Total change in length:

f, I= 6 m . 0.000022 mm . 100 K

For a temperature of 15°C during instal­lation the following values are cal culat­ed:

Expansion

IJ. t = 80°C - 15°C = 65 K 1 = 6 mm 0 a = 0.000022 m/ (m k) I = 6 . 0.0 00 022 . 65

= 0.00858 m = 8.58 mm

Contraction

IJ. t = 15°C - (-20°C) = 35 K I = 6 . 0.000022 . 35

= 0.00462 m = 4.62 mm

The total change in length 13.2 mm

is divided into an expansion of 8.6 mm

and a contraction of 4.6 mm

The se values should be born e in mind in respect of the appropriate fixing temperatu re and th e durat ion of laying in order to ensure the nece ssary steps are taken for the unimpeded longitudi­nal movement of individual bui ld ing components (DIN 18339).

To allow for longitudinal changes due to variat ions in temperature,expansion jo ints must be fitted without, however , enda nge ring water-tightness.

Guidelines for maximum spacings of expansion jo ints: With mastic bonding: abutments, eaves flashings, roof flashings, masti c bonded internal gutte rs, shed gutt er: . 6 m

Wall co pings and weatherings ; roof edge cover flash ings above water level, internal non -bond ed roof gutt ers, sec­tions over 500 mm 8 m

With panels for roof decking and wall c ladding, inte rnal gutters not sealed with mastic sect ions below 500 rnm: hanging gutter sect ions over 500 mm' . . . . . . .. . . . . . . . .. . . . . . . . . . . . . . . . 010 m Hanging gutters up to 500 mm sect ions . . . . . . . . . . . . . . . . . . . . . 15 mm

These guidelines are in respect of st raight lengths. Half the guideline val­ues apply wh en measured from cor­ners or ends (fixed point s).

Even where t he c lient fails to specify th e numb er; type and installation of expansio n joints, their supply and in­stallation as well as all construct ional matte rs in relation thereto will be co n­sidered as part of th e services to be carried out. Accord ingly VOB DIN 18 339 and the guide lines for th e exe­cut ion of plumbing work in build ing construct ion, issue Sept. 1985 (Zen­tralverband San itar Heizung Klima) contain obligatory instructions regar ­ding longitudinal movem ent due to temp erature fluctuations. It is c urrent ly the custom to calculate expansion joints separatel y as a main item of work.

m · K

0.013 2 = 13.2 mm [=':diJ ',._~f---6 m ~Distance of ex pansion x

II ~f-_I_ L _+ - T­I I I , i _' _ ~

From edges or ends ~ f-.- - - , I ' _1_ --'-__, _

I

13

RHEI NZINK nomogram for calc ulating lo ng itud inal ch ange as a fac tor of tempe rature

+ 8 0 +60 + 40 + 20 ± O - 20 fel 22

/ 20

10

10

12

14

16

18

20

1'-'-'-'-0-0---'---'-0---'--+ 22 +80 +60 + 40 + 20 ± O - 20("C)

M eta l laying lempe rature, Ii I - 100 K

C' Exa mple at 150(; and 6 m leng th

Construction of Expansion Joints

Compensation for expansion in exter­nal gutters, dimensions as per DIN 18461 , is assured by using the RHEIN­ZINK Dilatation Gutter, a ready-made 3 m roof gutter.

The integral chloroprene expansion component does not impede the flow of water and is invisible from outside. For information on installing expansion joints for gutters, see page 15.

For external gutters whose dimensions are outside the scope of DIN 18461 and internal gutters, a RHEINZINK str ip ex­pansion compensator is soldered in. See instructions for install ati on .

For valley gutters, an unsoldered over­lap of 100 mm suffices as a sliding seam if the sloping sides are over 58 % (30°); thp seam erigps of the overl ap­ping parts should be slightly notched to prevent suction (capillary effect).

With falls over 5% (3°) compensat ion can be arranged by means of dr ips (drip depth 60 mm). Where such step ­ping is not possible because of the subs tructure, or the fall is below 5 % (3°) , the individual lengths are jointed by soft soldering, and expansion joints are installed at spacings of 6 m. RHEIN­ZINK strip expansion compensators are suitable in these instances, as they do not obstruct the flow of water.

For parapet and cornice weatherings : various constructions to accommo­date expansion are pos sible. See 6.5.

When using RHEINZINK® joints or flashings for flat roofs, expansion boxes or ready-to-install expansion joints, made in the workshop, are used. See 6.3.

The expansion box made in the work­shop is not back-flow-tight; therefore compensation must tak e place above the water plane .

However, this type of construction is not only very labour-intensive, but also complicated . Consequently it may not fulfil its intended purpose.

The RHEINZINK expan sion compensa­tor, on the other hand , is a ready-to­install building component , whi ch can be installed in the water plane. It has a vulcani sed middle piece as an expan­sion part, made from highly elastic chloroprene. Chloropren e is an elas­tomer of durable high elast icity , which is suitab le for a cont inuo us weath er temperatures of - 40°C to +100°C.

Within this range no embrittl ement (cold britt leness or fissures) will occ ur. Thus chloroprene is resistant to all weathering in this temperature range, even to ultraviolet rays.

Chloroprene is not affe cted by tempe­rature due to soldering of RHEINZINK® profiles wh ich are to be jointed when a minimum distance of 5 cm is adhered to . For jointing to th e roof skin which is to be mastic-bonded, the expansion joint has a mast ic flang e of 140 mm (DIN stipulates a minimum of 120 mm - DIN 18338) .

The brie f temperature loading due to the use of hot bit umen is harmless. High er tem perature stress es than nor­mal hot bitumen (open flam e) are not allowed, nor is the painting or sealing of vulcanised chloroprene.

Expansion joint (sli d ing box) for kerb fla shing, made in the workshop

Sliding bo x ex pansion joint for abutment, made in the workshop

RHEINZINK 1-Head expa ns io n jo int for abutmen t

14

v

Cov ering in accordance with guide lines for flat roofs

I,

RHEINZINK expansion box gutter, Standard length 2.95 m

RHEINZINK-Det ail : 1-head exp ansion joint with bonded eaves flashings

Gutter expansion joint at the upper point of fall with two separate stop end s

Gutter expan sion joint at the lower point of fall with RHEINZINKplug-in oullet

Instructions fo r use For half-round and box-shaped hang­ing gutters in sizes in accordance with DIN 18461, appropriate 3 m long RHEINZINK Dilatation (expansion) Gutters DBM 7834576 are supplied . The sliding seams is in the water plane and does not obstruct water flow in any direction; further, it is invisible from outside . The 3 m long RHEINZINK Dila­tation Gutt er is installed in exactly the

same way as the normal gutter, and wi­thout additional expenditure of time. Jointing with the connecting gutters is by soft soldering.

For gutters with non-standard dimen­sions, expansion compensation is achieved by means of the strip expan­sion compensator. This is cut in ac­cordance with the gutter section and is rounded and folded to fit the gutter pro­file. In the zone of the expansion strip the gutter pieces to be jointed are loosely overlapped. The expansion strip is laid internally into the gutter, one side being under the water welt of the gutter. The sides of the expansion strip are jointed with the two gutters by soldering.

Prior to overlapping the gutter in the area of the expansion joint, a prefabri­cated beaded capping is screwed into the gutter profile.

Following soldering of the expansion strip, the beaded capping is displaced so that the free end grips over the edge of the expansion joint and makes con­tact internally with th e chloroprene strip.

This expansion joint is also a sliding seam, invisible from the outside. The base of the gutter does not limit water drainage.

Intermediate soldering of these expan­sion joints without overlapping of gut­ter pieces is also possible, for exampl e with shed gutters.

Expansion compensation for wall wea­therings, see 6.5, or cornice flashings can also be achieved with expansion strips in accordance with the above examples.

In order to fac ilitate the working proce­dures described above and to mini­mise the time spent on the building site, RHEINZINK delivers a prefabricat­ed dilatation capping .

This is an expansion element made in 3 m lengths for installing in a given pro­file with which it is jointed by soft sol­dering. The chlorop rene part must be covered with a cap , fixed only on one side by soldering, see 6.5.

The 1-head expansion joint is suitable for th e RHEINZINK abutment in the water plane (angle strips, eaves flash­ing, etc .).

The expansion joint can be bent to suit any particularly profi le and is jointed to it by soldering . Nails must not impede the thermal movement of the profiles or expansion joints. DIN 18339 therefore specifies th at only indirect fixing is per­mitted. For angle strips this can be achieved by using toothed strip or cl eats; for eaves flashings, by c leats (welted clips).

The clips must be spaced at inte rvals of not less than 20 mm from th e expan­sion joint. The part of the expansion joint proj ecting int o the roof area does not have to be additionally fastened.

15

The 1-head expa nsion joint must con­tact the roof area along a total leng th of 60 cm. When making an upstand on an an gle strip of , say , 20 cm therefore, a total lengt h of 80 cm is necessary .

Th e placement in the wate r plane is w it hout risk , as the seams are solde red to be wate rproof, and the upper layers of the roof fe li are bond ed to the f iarrge free from sheari ng forces.

The areas to be bonded must be paint ­ed with a co ld bitumen emulsion .

Care shoul d be taken that at least one b it umen layer of the roofi ng felt is ta ken up to the upper edg e of the profi le be­low the ang le joi nt or of the eaves flash ­ing. Inaddit ion a suitable bonding (slid ­ing ) strip should be fitt ed to bridge the t ransition from me tal to roof surface.

The 2-h ead exp ans ion joint is princi­pally used fo r installation in mastic bond ed inte rnal gutt ering.

Th e working and fitting procedure is simi lar to tha t for 1-h ead expansio n joints.

Th e approximate valu es indicated in the table in respect of maximum spa­cing s apply to all expansion joints, see 3.7.

The expansion joints may be formed on the custo mary fold ing ben ch es and ad ju sted to any desired profil e. The ra­d ius of the bending bar must be at least 2 mm. The lower bending bar must be ad justed in accordance with the th ic k­ness of the c hloroprene st rip to avoid shearing.Therefore it is recomme nded to back su pport th e metal du ring bend­ing and to co mpe nsa te th e upper side by fir m pressure. A minimum c learance of 5 cm from th e c hloroprene part must be maint ained during so ldering to avoid any contact w ith an op en flame. Po ssible adherent bitum en splashin gs on the chloroprene do not matter; however, chlorop rene must not be c overed with bitumen or bonded with b ituminous felts, as the fun ct ion of the c h loropre ne co mpo nent wo uld be nul­lified. Moreover, t his would ca use cracking and subsequen t pee ling, which would co nti nue und er the roof skin.

To speed up the work, it is recommend ­ed th at the ch loropren e co mp onent be covered wit h a protective sheet prior to the appli cat ion of hot bitumen. Th is must be removed once the bondi ng work has been com ple ted.

In the case of su bsequent work being undertaken by another fi rm, full infor­mation must be g iven regarding the process and meth od employed.

When adhering to th e recommended ins tru ctio ns regard ing the applicatio n

RHEINZINK expansion joints

Built-up roof ing 1-Hea d expa nsion joint

Strip expan sion j oint

RHEINZINK Di latat ion roof gutteri ng, stan dard len gt h 3 m - unimpeded water flow _

of these expansion jo ints, the longitu­din al chang es due to th ermal move­ment will be compensated for by the elastic properties of the ch loro prene com ponents. Thermal movement in mastic bonded sheets will be red uce d to almost nil due to the project ion of the expansio n jo int 's head into the roof surface. The mast ic bonding of th e roof sk in in the roof edge flash ing zone is al­most free from shearing forces. There­tore it will not c rack, and will rema in water-proof. See 6.3.

Box- shape d roo f guttering w ith chlo rop rene exp an sion joi nt and ca p fro nta l view

Shed gutt er w ith RHEINZINK roofing

No t visi b le fro m ollts id e

16

4.0 RHEINZINK® Roofing and Wall Cladding In the design and execu tion of roofing, wall cl add ing and weathering, a know­ledge of all the possible st resses in­volved and their relat ionship with constructional physics is nec essary. Responsibil ity for profes sional work is not limited to the laying tech nique alone. For this reason the relevant points are described in detail in the fol­lowing chapters.

In contrast to th e self-s upporti ng metal profiles, such as trap ezoids, wh ich are structurally reinforced at necessary in­tervals only, flat metal st rips laid to the double stand ing seam or batten roll systems are laid and fixed to a continu­ous su bstruc ture.

This substructure assumes a structu­ralfunct ion and must be laid in accord­ance wit h DIN 1052 and DIN 1055. The metal is th e roof sk in or wall cladding .

RHEINZINK0) possesses adequate strength and du rability to res ist th e stresses inherent in roofs and walls.

RHEINZINK® is classified as a non­flammable build ing material in accord­ance with DIN 4102, part 4 (Class A) and can theretors be used for th ese pur­poses without reservation.

4.1 Application Relative to Roof Pitch Jointing of t he indi vidual RHEINZINK® strips or bays in ac co rdanc e with the double stand ing seam or batten (Roll cap) syste m fo llows th e upturning of the edg es of the bays outside the water plane (see 5.0). The joints are rain- and snowproof but not back ­pressure-resista nt.

Th erefore p rovis ion must be made for drainaqe. In co mpliance with the gene ­rally recognised rules of the art (Guide­lines for the Execution of Metal Roofs ­Wa ll Cladd ings and Plumbing Work. March 198 3 issue) the minimum roof pitc h must be 5% (3°).

This requirem ent is justi f ied when con­sidering that var ious factors can affect roof pitch. With pitches under 5 %, de­pending on the lengt h of the roof and with norma lly admissible deflexion of the substructure, po nding may arise. Where the double standing seam of the battens are washed over by water, di­rect penetration or cap illary action will affect the bay jo ints with water seeping under the metal skin . As there is no vent ilation, this will cause condensa­tion in a part of th e area which may damage the metal skin from under­neath . See 1.4,2.4.

Where roof pitch is shallow, penetra­tion of water can be largely avoided by the heightening of the double stand ing seam or batten, as well as insertion of sealing strip s. These are matters for special arrangement and are th erefore not standard ised.

Where sealing strips are used, th ese must be inserted without a seam, as otherwise water may penetrate be­tween the joints. Subsequent inspec­tion will not be possible, and th e prob­lem wou ld be untrac eable and irreme­diabl e.

With correct structural analysis of the load-bearing substructure, the follow­ing are the admissible values, whic h negat ively influe nce the given roof pitc h.

Defl exion trapezoidal sheets 1 . 300 Deflexion stee l purlins 1 . 200 Deflexion roof frame 1 . 200 Deflexion concrete deck 1 · 200

(DIN 1045) Deflexion roof beams, t imber 1 · 300 Deflexion timbe r purlins, rafte rs 1 . 200 Deflexion gas concrete slabs 1· 300

These values apply not only on an indi­vidua l basis, but th e add ition of two va­lues is possible.

Acco rding to DIN 18202 part 3, con­crete decks are st ill co nsidered as horizontal wh ere the height d iffe ren­tials are 30 mm or 40 mm with respect to span widths from 4 - 10 m, orover10 m.

A meta l roof slope of 5 % is therefore the minimum. For greate r slopes, even

up to 90° (where the roof becomes a wall) the same methods of execution are emp loyed .

4.2 Ventilated Roof Construction With a doub le leaf vent ilated roof, the weather-resistant roof skin and load­bearing substructure are separated from the insulated structu re by an in­te rmediate cav ity. Here thermal insula­tion is loo sely plac ed on the enclosing concrete st ructure. The resultant oc­cupational moisture in the rooms and the trapp ed building moisture diffuse as vapou r in direction of the vapour pressure. In our climatic condition s this process occurs almost exclu sive ly from insid e to outside.

With a ventilated roof construction the vapour pen etrates the enclosing st ruc­ture and the thermal insulation abov e it , in orde r to mix with the fresh air c ir­cul ating in the area immediately above and disperse.

The enclosing roof slab consists of cast in situ co nc rete, prefabricated concrete components, timber, etc. , in the dim ensions dete rmin ed by structu­ral ca lcu latio n.

So lid co ncret e roof slabs are able to absorb moist ure and, moreover, act as a vapo ur brake. Diffu sio n of vapour is lower and more un ifo rm, peak loads are reduced and the ventil ation syst em is relieved. A vap our barrier can be dispensed with.

With all oth er enclosing roof structures part icularly with open or closed joints , this cushioning effect does not exist. To relieve the venti lati on syste m, provi­sion of a vapo ur bar rier, or,wh ere there is not muc h vapour present, a vapour brake below the insulation, is recom­mended.

A vapou r barrier has an impermeable metal fo il; a vapour brake reduces the quantity of vapour diffused. Impermea­bil ity (J.1 ' s value ) must be determined in accordance with the olrcumstances .

17

The vapour barrier or the vapour brake m ust alway.§ be arranged under the in­sulation when viewed from inside to outside. Installat ion of this layer above the insulation is not perm itted, as then water vapou r would condense unter the underlay and the insulation would get wet. The function of the insulation would be cons iderably impared .

A dequate insulat ion is the prerequisite for creat ing healthy and comfortable rooms. In addition, the insulation must protect the enclosing structu re from inadmissible thermal expansion. DIN 4108 contains the min imum values for the individual insulation spheres.

The vent ilation area is immediately above the insulat ion. The system and size of ventilation cross-sections are left to the designer.

The effectiveness of a ventilation sys­tem must not be restricted. When in­stalling air inlet blocks or protective grilles, the open cross section only is effective. When determining ventilation the maximum height difference should be used. Therefore the air inlet vents are usually installed below the eaves and the outlet vents in the ridge area, e.g. by top ventilation strips. The inlet and outlet openings must be distribut­ed as evenly as possible along the whole length, so that the air stream can reach every part of the vent ilation area and thus be effective.

The external leaf encloses the ventila­tion area, determines roof pitch (re­commended minimum 13% = 7°) and fully supports the metal roof.

Natural ventilation, also called gravity air ventilation, works in accordance with the Archimedes principle by lifting warm air in the ventilation cross sec­tion; this value represents the rising draught intensity of a chi mney system. The effectiveness of natural ventilation is dependent on roof pitch.

The uplift force (intensity of draught, velocity of flow) IS calculated from the height difference and weight differ­ence between the outs ide air t, and the ventilation cross-section t i.

In th is the air weight diff erenc es (Vi - Va) are a funct ion of temperature differ­ence bet ween exte rna l air t and the air in the ventilati on cross-secti on t.

Pressure equ al isation : 11 P = h (Vi - Va)

To ach ieve greater ventilation pressu re, an inc rease of he ight d ifference be­tween inlet and outlet appea rs to be the only practical possibility, sinc e the out­side temperatures and those in the venti lation cross-section represent given values.

Increased height can be achieved by roof surface vents (outlet openings) or correspondingly lower arrangement of inlet openings in external walls or air in­let pipes at ground or basement level.

Based on standard construction meth­ods, the following approximate values for ventilation cross-sections and the height of ventilation area would apply.

For roofs and wall claddings

Roof pitch under 5% (3°)

Roofs with internal slope (internal gut­ters) should be included in this classifi ­cation. Free ventilation cross-section 2 x1/ 400 (0.2 x 0.25%)

Minimum height of ventilation space 20 cm

Roof pitch 5 % - 9 % (3 - 5°) and 9 % ­36% (5 - 20°)

Free air inlet opening 1/500 (0.2 %)

Free air outlet opening 1/400 (0.25%)

Minimum height of ventilation space 10 cm

Roof pitch over 36 % (20°)

Free air inlet opening 1/500 (0.2%)

Free air outlet open ing 1/400 (0.25 %)

Minimum height of ventilation space 5 em

Wall cladding

Free air inlet opening 111000 (0.1 %)

Free air outlet opening 1/800 (0.125%)

Minimum height of ventilation space 2 cm

The abo ve values are based on roof areas w ith insulation as speci f ied in DIN 4108, normal room temperature of + 20°C and relat ive air humidity of 60 %. For the structure below th e vent ilat ed area, all parts should have a diffusion res istance of !J . s = 10 m.

In th is: !J = Water vapour diffusion resistance coeffic ient of in sulation element or construction under the ventilated area.

s = Thickness of thermal ins ulat ion ele­ment or construction under the venti­lated area in m.

Where the ventilation path exceeds 10 m, the height of the free ventilation area should be increased accordingly.

In general, the following applies; The air inlet opening should be placed as low as possible; the outlet opening should be placed as high as possible.

The data here presented are guide val­ues and applicable in normal cases. In every case, however, it is the responsi­bility of the designer to indicate exact values in respect of cross-sections for ventilation, based on building physics.

!rnportant: With the frequent use of fibrous insula­tion materials in roof construction, at­tention has to be paid to exclusive ap­plication of the types W or WD to DIN 18165. Insulation materials of the type WZ are to be strictly avoided because of subsequent swelling (ultimately 30%) and resultant restriction in cross­section of the ventilation cavity.

18

4.3 Non-ventilated Roof Construction In singl e-leaf non-venti lated roofing a ventil ation syst em is inapplicable, so there is no cross -vent ilation of inter­mediat e zones. The cei ling slab of th e upper floor is also the roof floor and suppo rts the enti re roof structure. This consists, in the direction of th e thermal path , of a level ling course, a vapour barrier, insulation, a vapou r barri er, in­sulation, a vapour pressur e equaliser and roof skin.

The function of the single-leaf non­ventilated flat roof depends, inter alia , on the acc urate laying of the vapour barri er in accordanc e with co rrec t ca l­culations based on cons truc tional princ iples . To be effec tive the vapou r barri er must be laid with sheets whi ch have metal inserts of aluminium or copper=0.1 mm. These barriers being vapour-proof, their task is to stop the migration of vapour to the cool er outer zone and prevent condensation and a fall in temp erature, so the seams must similarly be vapour-proof. If not, vapour will seep through seams and insula­tion, damag ing the latter. As there is no cross-venti lation, the insula tion cannot dry out. It absorbs moistu re, thus ap­preciably impairing its effectivenes s. Moistu re is collected like a sponge and is transferred to the roof skin. So the funct ion of th e non -v entilated roof will be negated . Where the outer ski n is of metal, corrosi on damage may subse­quently occur, effec tively destroying the metal. See 1.4.

Following the requ irements of buildin g physics, th e non-vent ilated roo f lacks the nailable basis necessary for se­curing the meta l roo f. A practicab le fixing of the metal roof is pos sible onl y with wooden batt ens. These must be secured th rough the vapour barrier with the roof slab and then bedd ed in bitumen to reseal the vapo ur barrier.

For all thes e reasons the installat ion of meta l sheets on non-ventilated roof substructu res cause problems and th is type of work is undertake n only in exceptional circumstances.

4.4 Building Physics ­Terminology Vapour Diffusion Moistu re content: At a temperature t air ca n abso rb only a defined quantity of water: 1 m3 saturated air exerts a de­fin ed pressure, the so-called satura ­tion pressure Ps. With partia l saturation partial pressure P results.

Relative air humidity qi: Ratio of actual vapour quantity d to saturation pres­sure quant ity d, or of actual vapour pressure to saturat ion pressure:

cp = d . 100 or P' 100 % d P

Condensation: The actual quantity of wate r is greater than the absorpti on capacity of the air (sa turatio n quantity) at a defined temperatu re.

Moisture migration in const ruction: a) Vapour diffusion in dir ect ion of va­

pour pressu re (in relation to tem­peratur e)

b) Capill ary effec t in direction of hu ­midi ty release

c) Hygroscopic equilibrlurn moisture

Vapour perme ability resistance is de­pendent on th e material, its st ructure, porosit y and surface .

Porous materials, i.e., those with good insulat ion properties, are generally more vapour permea ble than less por­ous on es, but th is is not always a mar k of wat er vapo ur permeability.

A comparator is the dim ensionless va­pour diffu sion resistance coe ff ic ient I-l which shows the resistance of a mate­rial in comparison with an air space of equivalent thickness .

A com parison of two materials of dis ­similar thickness is calcu lated from the diff usion resis tance I-l . layer thick ­ness s (IJ . s) .

It is essent ia l to use the co rrect se­quenc ing of layers du ring construction to avoid con de nsatio n.

Thermal insulation Basic termi nology

Heat conductiv ity A Movemen t of heat W, which in the inert state pass es through 1m2 of material at a temperature diff erence of 1 Kim .

t-. = W/ (m' K)

Heat conductance coefficient A Movement of heat which in the inert state is transmitt ed through 1 m2 of building element of thickness's' (in m) at 1 Kim temperature diff erence be­tween the tw o surfaces 11. = W (m2

. K). The heat co nducta nce coeff ic ient is calculated according to the following formula:

A Heat conduction s Thickness of material in m

Resistance to heat conductance 1/t-. = Insulation value = the most important term in build ing phy sics relatin g to thermo stat ics: Heat tran smission re­sistance is the rec ip roca l value of A

1//\ = m2. KIW

Coefficient of heat transfer ex Movement of heat which in the inert state is exch anged between 1 m2 of a surface and co ntact air at1 Ki m tempe­rature difference of air and surface. This coe fficient depends on a number of fact ors, suc h as air movement, etc .

ex = W/ (m2 . K)

Heat transiei i'dsis',ance 1Iex = rec iprocal value of ex

1/0 = m2 . KfI"!

19

Air Temperature a Moisture co ntent (q/rn") at relat. humi d. Satn. water

vap. pressure °C 100% 90% 80% 70% 60% 50% 40% 30% Ps IJ bar

- 20 1.1 0 0.99 0.88 0.77 0.66 0.55 0.44 0.33 1.02 - 10 2.37 2.13 1.90 1.66 1.42 1.19 0.95 0.71 2.59 - 5 4.85 4.37 3.88 3.40 2.91 2.4 3 1.94 1.46 6.09 + 5 6.81 6.13 5.45 4.77 4.08 3.40 2.72 2.04 8.70 + 10 9.42 8.50 7.55 6.6 1 5.66 4.72 3.78 2.83 13.05 + 15 12.85 11.57 10.28 8.99 7.71 6.42 5.14 3.85 17.01 + 20 17.32 15.59 13.86 12.13 10.40 8.66 6.93 5.20 23.31

Mo isture content of air & water vapour saturation pressur es at variou s temperatures & relativ e hum iditi es.

Table 2. Minimum va lues of res istance to heat transmission 1/A of no n-transparent building components for living rooms as specified in section 1 (with the exception of light building components in table 3) Extrac t from DIN 4108 , part 2

Co lumn 2 3 Resistan ce to hea t transmission

Line

1

Bui lding components 1/11 2m . K/W remarks

genera lly 0.55 For small area ind iv. co mponents

everywhe re ground f loor (1st useful floor area) ;;;; 500 m above NN

1 ~1.2 External walls 0.47I (e.g. pil lars) in bui ldings with a

in non-ce nt rally heated bui ldings 0.25·Living room walls and walls betw een everyw here2 ~ extraneous workin g rooms 2.2 in centra lly heated build ings 0.07

3 everywhereStai rcase wall s 0.25

K+ 0.35 Living-ro om cei lings & ceili ngs general ly everywhere4 4.2 bet w een extra neous rooms in ce nt rall y heated offices 0.17

Be low living roo ms with no basement under 5 everywhere

the subsoil) (bo rd er ing, directly or via a non -ventilated void, 0.90

everywhere 0.90 ~ Ceilings under non- f inis hed att ics6 6.2 in the least fav. place 0.45 7.1 average 0.90 Cell ar floors7 ­7.2 0.45 in the least fav. place 8.1 1.75 average8 Floor s between living rooms & the atmo sphere be low !i'2 in the least fav. place

.si, 1.30

average1.109 Floo rs between livi ng rooms & the atmosphere above 9.2 0.80 in the least fav. place

Heat t ransmi ttance coeffici ent k Heat t ransmittance res istance 11k Mo vement of hea t whi ch in the ine rt = reci pr ocal value of k st ate is transmitted throu gh 1 m 2 of building mater ial of th ic kness's' at 11 k = m2

. KIlN 1 Kim temperature difference of adja­c ent air (room air - exte rna l air)

k = W/(m ? . K)

20

4.5 Substructure 4.5.1 Roof Boards Timber roof board ing is general ly used for the metal shee t substructure, since no prob lems aris e with fixing or co n­struct ional requirement s. Air-d ried pinewood, grad e II, unpl aned, with clean edges and a minimum thi ckness of 24 mm and width of 80 mm to 140 mm is a suitabl e materia l. Fungicidal and in­secticida l impregnation is required , as laid down in the relevant building regu ­lations .

In general t hese pre servatives are a mixture of various chemical composi­tions, which may be acid, neu tral or al­kaline. For thi s reason an underlay is advisable, si nce the compatibili ty of preservatives and metal ca nnot be guaranteed .

The criteria governing the choice of wood preservat ives are the following :

1. Water-soluble preservatives as a pro tection aga inst fungi and in­sects fo r under-roof timber or tim­ber exposed to th e atmosphere. Symbols: P Iv SW

2. Water soluble preservatives as protection aga inst fung i and in­sects for under-roof t imber. Symbo ls : P Iv S

3. Explanation of symbols :

P = effective against fungi (rot ­proof)

Iv = effect ive in preventing att ack by insects

Ib = effective as an insectic ide

S = for paint ing, spraying and immersion of building timber

St = for paint ing and immersion of building t imber , as well as spraying in situ .

W = also for timber exposed to the weat her, but not in co n­tact with sa il or water

For fire-proof ing there is a foaming agent fo r under-roof t imber, tested in

accordance with DIN 4102 part 1 Class B1.

In roof areas where the substructure is required to comply with fire protection regulations (class A), gas co nc rete ele­ments, trapezoidal profiles or fibre con­crete slabs can be used in place of t im­ber. In th e case of the expand ed co n­cre te, the fastening of th e c lips is by th readed dowels; for t rapezo idal pro­fi les by aluminium cavity rivets, and for fibre concrete slabs by special dowels and co rrosion- resistant screws. It is pointed out that trap ezoidal profiles should be used only for stee p-sloping roofs (= 60") that cannot be walked on. See 5.4 .

Underlays have a double function: In the first place metal mus t be protected against moist t imber, but in part icu lar against impregnating agen ts ; second­ly the underlay pro tects the work in case of rain while the plumbing wo rk is in progress.

It is reco mmended that the underlay be of bitu minous glass fibre as specified in DIN 52 143, light ly sanded or talced. The und erlay is placed with 8 - 10 cm wide overlap joints of th e seams. The overlap must be fasten ed with broad ­headed galvanis ed tac ks and the joint s may also have to be packed with mas­t ic sealant.

Where in the case of a flat pitched roof up to 25° the underlay is not requ ired to comply with fire -proofi ng co nd itions, perforated bit uminous mat sheeting shou ld be used.

For a better result in the eaves area th e use of a 40 x 140 mm wooden plate is recommended. The surface of th e plate should be fix ed 5 mm below the res t of the roof surface.

In accordance with DIN 1052, Timber Cons tru ctions, Part 1, 11.3.20 , boards must be fixed with at least 2 nail s to ev­ery rafter, frame or po st.

Calculation of extrac t ive values is omitted for nailing in head grai n wood.

In accordance with DIN 1052, part 1, Table 16, the permissible extractiv e

st ress in respect of 3.4 x 90 nails is 200 N/nail for 24 mm timber.

4.5.2 Wood Chipboarding In the Rules of Workmanship of the Ex­ternal Plumbe r's Trade,as well as in th e RHEINZINK® Instructi ons for External Plumbe r's Work (cf: RHEINZINK®-Ap ­plica tio n in Buildi ng 7th Edit ion 1984) ch ipboarding (partic le boarding) is described as unsuitable for use as roof board ing under metal roof cover­ings withou t, however, offer ing more detailed reas on s for this.

The term "unsuitable" has resulted from cases where damag e to metal roof co verings , including zinc, has aris­en in connect ion wit h chipboarding.

For us it is incomprehensible that chip­board, for so-called economic con ­sideratio ns, sh ou ld be repeated ly spe­cif ied and actually used as a roof boar di ng,and we cont inue to reject th e use of chipboard - incl uding isocya ­nate-bonded boards - as a roof board ­ing mate rial in connect ion with RHEIN­ZINK®. As explanatio n for th is refusal we offer th e following reasons, which result from practi ca l exper ience :

The supposed advantages of a lar­ger board size have proved in prac ­tice to be a disadvantage, espec ial ­ly inconvenient in articulated areas of roof and facade .Assembl y is only poss ib le in dry weather as chip­board is susceptible to mo ist ure.

High specif ic densities are incon­venient in the layin g procedure ; the presc ribe d thickness of at least 25 mm is mostly more expe nsive than rough board ing (natural wood).

Normal phenolic- resin-bonded chip­board is hygroscop ic, i.e. it takes up moisture, absorbs it and swells in the process. This is true also for iso ­cyanate-bonded boards in the core area (moisture penet ration via the jo int s).

In the most f requent ly used chip­board Typ V100 Gto DIN68 763,the G sig nifies protection against fun­goid attack. The fungicide com­

21

pound contains fluor ine and has, in combination with condensation, a corrosive effect. The sodium hy­droxide (l'-JaOH) contained in chip­board is soluble in contact with moisture and during evaporation crystallizes as an alkaline salt. This can always become activated with water and therefore strongly corro­sive.

The incidence of moisture in roof boarding can never be completely excluded, whether through vapour diffusion orthrough slight leakages in a standing seam covering. There is no natural absorption and evapo­ration of moisture, as with wood .

With this characteristic of phenolic­resin-bonded chipboarding, the formation of condensation below the metal skin may occur rapidly.

A cross-section through chipboard reveals varying densities (s) : External layer: s = 0.9 Core layer: 0.55 - 0.6

i.e. the core layer is more moisture absorbent (hygro­scopic) than the covering surfaces.

This gives rise to differing degrees of resistance in chipboard, with varying degrees of moisture ab­sorption and an increased inci­dence of vapour diffusion in the jointing zones of the board, which represents an increased hazard for the metal roofing skin.

The negative characteristics of chip­boarding applied as roof boarding and extensive experience arising from cases of damages explain the use of the term "unsuitable" in connection with a RHEINZINK® roof covering.

Isocyanate-bonded chipboard of the type V 100 G ISO can be permitted for facade application; owing to different physical conditions a corrosive 'effect from this type of chipboard seems here to be considerably reduced. In prin­ciple, however, if fire protection re­quirements allow it, a normal rough boarded lining should also be used for facade areas. From the point of view of building physics wood is the optimum matenal tor boarded linings to RHEIN­ZINK®facade cladding.

We therefore rec omm end that where chipboarding has been specified for wood linings, fundamental reserva­tions should be stated in writing and a guarantee for the roofing contractor's work using such boarding should be rejected, unless the chipboard manu­facturer is prepared to cover these risks with his own statement of guaran­tee.

Concrete Direct contact between metal and con­crete, light concrete, stone and mortar must be avoided.

To mix 1 m3 of reinforced concrete, some 150 Iitres of water are added, and for1 m3 mortar the quantity isabout 200 lit res.

A proportion of the mixing water is che­mically bonded. The remainder, how­ever, possibly increased by subse­quent moisture or rain, constitutes the trapped moisture in the concrete or mortar. This residual trapped moisture can amount to no less than 100 litres per m3 concrete. These values make clear the quantities of water which must evaporate until the concrete has dried out. The drying out process can take several months. During this time the remaining alkaline­enriched water separates from the building and aggregate materials. Pe­

4.6 Fixing Sheet Metal Roofing with Regard to Wind Suction Forces The anchorage and method of fasten­ing are crucial factors in the fixing of the roof skin to the substructure. DIN 1055, part 4, Loads for surface struc­tures, traffic, wind loads of building work not subject to vibrations, pub­lished May 1977, lays down that all forces arising from wind stress must be

netrat ing under th e metal, it con ­denses.

All metals, including RHEINZINK®, must be protected against these dam­aging effects of con crete, breeze con­crete, mortar and stone. The underlay must also act as a vapour brake and the base fully sealed with mastic. Including its hot bituminous layer, a glass fibre bitumen layer in accordance with DIN 52143 has a vapour diffusion resis­tance factor of 2000 ; a metal foil , 0.1 mm thick, coated on both sides with bitumen, is vapour-proof.

4.5.3 Wall Boarding The substructure for the facade is sub­ject to the same rules as the roof, ex­cept that in the vertical area isocya­nate-bonded wood ch ipboard Type V 100 G ISO, = 25 mm th ick can be used.

Special fixings for the substructure, for example fibre concrete slabs and tra­pezoidal profiles, are possible; they must, however, be conceived and de­signed specifically for the purpose. In such cases our technical department should be consulted.

Furthermore, plastic sheetings are suitable as an underlay for facades. The sheetings allow quick and simple execution of work.

Section A-B

-J ~{ ~ ; L Roof areas for cp values arising (DIN 1055, part 45, Table 4)

The following wind suction loads (W) are calculated in N/m 2 :

Roof pitch Hei ght of Building Corn .area edge area normal area

0-25U

(0-47%)

0­ 8 8- 20

20-100

1600 2560 3520

900 1440 1980

300 480 660

26-35° (48-70%)

0­ 8 8- 20

20-1 00

900 1440 1980

550 880

1210

300 480 660

22

safel y directed f rom where they arise (e.g. the roof skin) via all ot he r building co mpon ents into th e anchorage (DIN 1052,Timb er Structures ,Part 1,11 .3.20) .

To determine the nec essary number of tacks or nails per unit area, the techni ­ca l specif icat ions of DIN 1055, part 45, load s for surface st ructures - traffic loads - must be taken into account. The suction load s applicabl e to a roof

are essent ially inf luenced by roof shape, as well as height and position of the building .

Peak suction loads arise in the ex ­posed roof edge and corner areas.

4.7 Number and Spacing of Fixings The basis for calculating the total num­ber of clips or the number of cl ips per m2 for absorbing wind suction load s is

1600 N. Si nce, however, the 50 cm sp acing rul e cannot be exceeded (see Table), even in respect of screwed­down cl ips, the use of screws is appro­pr iate in spec ial cases only. (Corner and edge areas of buildings over 20 m; buildings which are exposed du e to

ing from methods of f ix ing.Practice has shown, however, that att ention must be paid to correct adju stment of pressure for complete punch ing in of the nails . Should nails sti ll protrude through in­correct pressure sett ing or wrong handling, they must be worked over in

-.lb..e..naiLeJDrac1.LlLe.1ill.c~ELLeJatL\!JU{LOall1il_-tk;-m-""";ofir;:oi"t">..........,"",,,=""'------r<= rr;-;;--.--r;-~=---;-;-;==T;"";""l~=~ ;-no ;-;:;­size and substructure.

The results of extensive tests have es­tablished the following guidelines in agreement with DIN 1055 parts 4 and 45, and which are calculated for the least favourable load in respect of roof pitches from 0 to 25°

So far as RHEINZINK i material is con­cerned, the minimum requirements are as follows: hot dip galvanised steel large flat head nails (deck tacks) 2.8/25.

Clips which are fastened with 2 nails of the above type can be used with an average extractive value of 560 1\J. Where nails other than these are used to secure the clips, only those with a shank diameter greater then 2.8 mm and a grip length of at least 20 mm are permissible.

Where clips are screwed down with 2 countersunk head screws 4.0/25, the average extractive value increases to

their particu lar POSition).

The nailing machines that have be­come available over the past two years have proved extraordinarily helpful in assembly. Extraction tests have indi­cated that there is no difference result­

order to ElVo ld unsigh tly bumps In the metal surfaces.

Based on an average extractive value of 560 N per clip, and adding a margin for safety, the table below is offered as a guide.

Number and spacing of clips in relation to height of building and least favourable roof pitch (area of highest wind suction loads). Note: Spacings greater than 50 ern are inadmissible.

Corner & edge areas Norm al area st rip w id th / co ordi n. axes" strip width / co ord in. axes" Height of

800/73 0 Buildi ng 600 / 530 700 / 630 800 1730 600 / 530 700/630

Him ' cm/Hcm/ H Him' c m/H Hi m' cm / H Hi m' cm /H Hi m' cm/Hm Him'

50' 42 40- 8 4 50' 4 42 4 36 4 4

8- 20 6 33 6 28 5 40 5 33

20- 10 0 6 338 25

Him' = cllps/rn" crn/ H = c li p spaci ngs in c m • = max. c lip spac ing (10m length of sect ions)

•• = width of bay"" unit spacing (coordinated axes)

Widt of Strips and Thickness of Metal Strip width is relat ive to building height. Generally a standard width of 600 mm and 0.70 mm metal thickness applies. These dimensions also apply to build­ings hig her than 20 m, whose loads are not in excess of those indicated in DIN 1055.

In exceptional cases, with buildings of lesser height, wider strips of greater metal thickness may be used.

He ight of Strip width Metal gau ge bu ilding

0 - 100 m 600 mm 0.70 mm

0 - 20 m 700 mm 0.70 mm

0 - 8 m 800 mm 0.80 mm

For sheet roofing similar values apply. Roof pitch must be greater than 13 % (]O).

Prior to current practice 1 x 2 rn, 0.80 mm gauge panels were used. This was in the days before strip was produced. On the narrow sides the individual pan­els were also jointed by means of a flat double cross-welted seam. This cross welt divides up, as does the double welted stand ing sea m, wind sucti on

36

4.8

23

fo rce . This type of panelling is adm is­ Eaves flash ing for RHEINZINK wa ll s ib le for buildings up to 8 m high. cladd ing at the lower edge

All owances for seams Tables 5 and 6 in section 9 show the " losses" in relation to seam or batten hei ght in relation to the do uble stand­ing seam and batten rol l sys tem. The ext ras needed for calculation are sh own in the tabl es.

4.9 Eaves lashings

Proj ect ing eaves edgi ng str ip for RHEINZINK in Metal Roofing coveri ng , e. g. for cu rbs, stepped co ver flash in gs, etc. Usual sec tio n 200 mm

Eaves flashings for metal roofing have a special function. They are not seals in the acce pted sense , but have the fun c­tion of a continuous edging strip with an extra projecting edge (a preformed apron) which is folded out at least 25 mm to engage with the metal roof skin. See 5.

The function of the eaves flashing can be considerabl y enhance d when an angled strip elf 0.80 mm th ickness has previously bee n nailed to it which reach es deeply into th e projecting edge of the flash ing .

Th e eaves flashings should be to a depth of 10 cm on the timber board and are fixed , like clips, by staggered nail­ing at 50 mm int ervals .

The individual lengths are not jointed but laid with a loose overlap of approx. 5 em. Only flashings whose projecting ed ge directly adjoi ns th e water stop of the panel can be laid at 2 - 3 mm inter­vals in individual lengths. Min imum thickness of th e str ip is 0.70 mm .

For roof pitc hes of 7° (13%) th e eaves timber board should be fixed 3 - 5 mm bel ow the metal roof . This will avoid wa ter acc umulation arising at the edges due to th is particular de tail.

Eaves flas h ing tor RHEINZINK roof. Roof gutte r with o r w itho ut fall s sec tion ?RS mm min

24

5.0 Roof Covering using the Double Standing Seam Method The name de sc ribes th e meth od of joining adjacent sheets or bays . The heigh t of th e standing seam should be at least 23 mm. Some text books state that the minim um pitc h is 5 % (3°) but pract ical experience has shown that slopes of 5% (and less) nearly always cause prob lems. When using long lengths - max. 10 m - we have found that very ofte n insu ffic ient provision , if any, has been given for thermal move­ment , espec ially at th e eaves. During a cold spell (at winte rt ime) th is co uld cause th e bay to lift at the eaves and re­sult in pond ing with deposits of dirt, thus prod uc ing a potential corrosion area. A similar effect of this kind of un­knowin gly built-in corrosion is behind the "waves" which would develop along the wh ole length of the bay.The rate of corrosion increases for lower roof pitch es.

We therefore recommend a minimum roof pitch of 13 % (7°) for bay length s of 5 m and longer (see also page 2).

Clips for machine fixing

The RHEINZ INK PROFIMAT/FA LZOMAT

The angle seam should not be used on roof pitches below 25°

Peak mechanical stress of the roo f is caused by the suction effect related to the wind direction and str ength. These suction forces are not uniform but vary in strengt h and duration , they act on the metal roofing ski n wit h differing forces be ing app lied to separate pan­els and even along the length of the same panel.

To ensure correct use of RHEINZINK® and to avoid flutt ering and subseq uent c racking, the panel widt h dimensions

Double standing sea m - for fi xi ng with RHEINZINK PROFIMAT/FALZOMAT

and thickness details are spec ifi ed in Section 4.8 . These must be followed .

The sheets or bays are fixed by indivi­dual cli ps to t he substruct ure and th ereby th e "attacking" fo rces are dis ­persed and diverted . See Section 4.5. The frequency of clips and spac ing re-

Double stand ing seam - for fixing manually

Bay wid th "'" un it spac ing

Angl ed stand ing sea m

douhle standi nq sea m

.~

///

Clips fo r ma nual fix ing

25

lative to the hei ght of th e building, for no rmal and exposed areas, may be tak­en from the table in Section 4.7.

Every clip must be fastened down with two hot dipped galvanised deck nails (2.8/25 mm) penetrating at least 20 mm into the timber.

When the bay length is more than 3 m, s lid ing cl ips must be used. How ever, within a stipulated distance of 1 rn, four fixed clips must be positioned within the standing seam to prevent any slip­ping.

The position of the fixed clips is de­pendent on the roof pitch illustrated:

~ %:/ ~ /1%

~~ :ro0 ~ I ~ ~~ ~ ~ ~r:a ~~ -~

1m

!.. 11 1... 1 i If --1

~~ 3° (exceptionally) > 30°

Single cross seam Roof pitch ~ 47% (25°)

Single cross seam with soldered clip Roof pitch ~ 18 % (10°)

Double cross seam for roof penetrations or small deckings with sheets Roof pitch"= 13% (YO)

Drip Roof pitch .2:. 5% (3°)

:2: 60 mm

cress seams tor RHEII-JZINK roofillg

The bay length must be continuous metal , up to a maximum of 10 m. Bay lengths made up of smaller pieces joined together by soldering or welting should not be used.

For bay lengths over 10 m a stepped fall must be introduced.

For roof pitches over 18 % (10°) a single lock welt with an additional soldered undercloak may be used as an alterna­tive method of fixing.

The height of a stepped fall should be 60 mm minimum, and provided for in the substructure plans. A step is achieved by parallel lowering or by the introduction of angled fillets into the roof detail.

About 150 mm from the eaves the double standing seam is turned down through 90° with the folded side upper­most. The end of the turned down standing seam may be folded-in with the sheet or bay end around the spac­ing template.

26

The sheet is engaged into the folded Variou s possibil it ies for finish at eaves edge at the stepped fall. Here too ca re must be taken to allow for the linear n

I I I I

4 5 35

I

Jl.i:: l 0 mm

45 3 5

- 25

[k ~~ Stand ing double seam - swabian method

~

I \.- ­

I

I I

I =:h- ---t­

71 ~I Stand ing double seam

"

standard dimen sions (mm)

45

m

35 f---

~

~ ICurve

stand ing angled ca pping, fin all y c urved

method, whi ch has considerably work­ lower end is visually the best, and ma­ing advantages, any possible probl ems nually the most dem and ing, end detail; of lateral expansion can be ruled ou t. it is particularly suit able for horizontal

curbs and superior lower edge detail ­Th e double standing seam with angl ed ing .

Detail: step ped fall

thermal expansion of RHEINZINK® metal. The turned-down edge of the bay must not be able to disengage it­self from the eaves flashing during thermal expansion, and conversely, there must be sufficient room to allow for a fall in temperature and free con­traction of the bay .

To achieve this obj ect ive, as well as a straight edge, a spac ing templet should be used.

finish at eaves with standing welt

Experience has shown that the double seam need not be folded over in all roof pitches as the eaves flashing would prevent any minor ingress of moisture arising . Moisture penetration due to capillary action can be dismissed al ­t ogether and th erefore no damage should occur.

The double seam is cut at the eaves nod only tho end of the sheet is en­

~~~.~.~..!.n .~ ~~ ~~':'::~. ! ~c:.s ~! ~g ...I.n__!~i ~

27

10 10

o on

I I I-~----

I I J20 ! -.1-- - _ _

\

I I I' I

/~'~ ~// Working sequenc e of j ointing double standing Seam claddinq to upper roofs by making a pinched seam

An upstand is made at the upper end of th e bay. The height and finish of the upstand will dep end on the jointing de­tail. For jointing with ridges, hip rafters, and verge s without ventilation, a joint­ing height of 40 rnrn suffices. Joints to ridge ventilators and walls must be 150 mm in height. For ste eply pitched roof s from 25° , heights of 60 - 80 mm are adequate.To be weathertight, the joints must be completely conti nuo us.

To balance out small height differ­ences a backing is used to bridge the stepped fall . Following this, after ex­tracting thewedge, 60 mm plus jointing height of the double welt is turned down with the welt , and the folded edge marked .

After this the end of the bay inc luding the turned down double standing seam , is folded up and then folded back 20 mm.

Where, for reasons of space, this meth­od is not possible, the double standing seam must be finished as a pinched seam.

~ / /--- _ - ­

/ I

- ~ ~ •

/ ~ -----­/ .//~--

/ ' ~ //

~ / ~

Jun ction with turn ed down double seam

With both finishes a distance of 10 mm must be main ta ined between the base point and th e area to be joi nted, to avoid buckling during thermal expan­sion.

In this way the necessary measures have been taken to assure the unim­peded expansion and contracting of the bays parallel to the double stand­ing seam, wit hout causing leakage .

Similar facilities for unhindered move­ment must be created transversely to the double standing seam. When the bays are laid, th is must be at intervals of 3 mm. This suffi c es, and expansion strips and separators, even in large roof surfaces, need not be used .

Thus expansion strips are only rarely specif ied. Where they are, however, the work must be in accordance with the batten system as described in Sec­tion 5.1 .

pin ched seam

Turn ed down double scam

28

t-------' I I Half round rainwa ter gutter in accordance with DIN 184 61 wit h cornice de tai l

in

Saw tooth roof RHEINZINK double standing seam roofing Deta il : Shed gutt er Win dow joint V0. rg p.~

29

5.1 Roll Cap System Th e roll cap system of roofi ng is the o ldest metal roof ing syst em still in use.

T he roll cap roof is characterised by the wooden batten, to which the 12teral up­t urn s of the bays are jointed. The wood batte n is covered with a capping. The capping embraces th e lateral upturns of the bays and so makes the roof rain­proof.

M inimum pitch , metal gauge , width and length of bays, dist anc e between c lips , as well as the tec hnical spec ific atio n in respect of cros s welted joi nts and st epped fal ls, are in accordance wi th the rules governing th e dou ble sta nd­in g seam roof whi ch are appl ica ble here.

Because the water stop is omitt ed in th e Belgi an wood batten system, appli­cati on must be lim ited to roof pitches between 25° and 75 °, as resistance to wind-driven rain will be abse nt. In shal­low sloping roofs th is sys tem will not be back-flow-resistant.

In comp arison with the narrow doubl e sta nding seam , the joint with th e bay is more strongly profiled due to the size of th e batten and is th erefore more vis­ible. For th is reason th e batten system is to be especially co nside red wh en designin g roof areas.

The wood batt en measures 40 x 40 mm.

The height or width of the wood batten may be increased if requ ired . Greate r hei ght is parti cularly recomm end ed for low -pitch ed roofs in regio ns subject to heav y snow.

Because of thermal expa nsion th e spacing of the wood battens must be 5 mm greater than th e clea r wid th of th e bays where square or rec tang ular bat­te ns are used. The inclin ed lateral up­turns of the bay th en co ntact the wood battens with the ir up per edg es only. By this mean s the necessary space at bay level is guaranteed.

The clips for fasteni ng the bays are se­cure d to the wood batt ens. The woo d battens must be securely anchored on the substruc ture, so that they can ac ­co mmod ate th e st resses effecting the bays.

Essentia lly two types of roll cap system are used, namely th e Belgian and the German met hod. The shape of the bat­ten is the same for both. The difference betwee n the two meth ods co nsist s in th e form of jo intin g the bay to the bat­ten, the cap ping and the fixing of c lips on th e batte ns, as th e drawings which foll ow illus trate .

The sheets are sec ured laterally by clips.

In th e Belg ian meth od the c lip is se­cured to the wood batten . It has a width of 40 - 50 mm. ln the German method a strip is nailed with 4 nails on the upp er side of th e wood batten. Becau se of the

lesser st rength of thi s st rip, it must be at least 100 mm wide, where the Belgian princ ip le of c lip arrange ment is not used. Therefore , in the batten syste m the bays must be protect ed agains t slipping in an area of 1 m (see illustr ation).

The ca pping is formed in accordance with th e meth od se lected, and en­gaged into th e cl ips, wi th 5 cm over­laps . A nail into the batt en prevent s it sli pping.

Simultaneou sly the nail secures a spri ng which holds the last batten in place, as nails ca n no longer be used here.

At the eaves th e end of the bay is en­gaged into the projecting edge of the eaves flash ing in accordance with th e code of practice governing th e double standing seam roof. Finishing and jointing of the bay to the battens at the

Fixin g to preve nt slipping of the bays in the Be lgia n rol l cap system

The roll cap sys tem - Ge rman meth od

Roll cap system - Be lg ian metho d Fix ing to prevent slippi ng of the bays in the German roll ca p system

30

eaves is diff erent in th e Bel gian and the Working sequence: Jo inting battens to up pe r Work ing sequ e nc e: Jointi ng battens to eaves German method and must be executed constructions (pinc hed seams).

in accordanc e with local requ irements .

The up per junction of the bay to upper paris uf slr uclures is simp ly ac hieved I by means of a pinched seam (see illus­

.>/~ trat ion).

As for the rest, th e code of practice in respect of double st anding seam roofs applies here , as we ll as to the lateral jointi ng of a roll cap roof to walls .

Detai l : Ap ron cladding in co mb ined sys tem.Main spacing batten, intermediate spacing ang led stand ing seam

Ge rman roll ca p sys tem with eaves and ridge cap ping.

Detail: Facade c ladding in combined sys te m. Main spacing batten, inte rmediate spac ing angled standi ng seam wi th stagge red c ross welts.

rarapet wall cladd ing with vertical joi nts in Ge r­man roll cap syste m.

31

5.2 Jointings with RHEINZINt(® roofing All joints to th e eaves (see 4.9), verge, ridge and wa ll (parapet) must be con­tinuous and for me d witho ut seams f ro m the RHEII\JZINK® roofing to avoid t he risk of water permeability. To accommodate therma: expansion of the RHEINZINK,i, roofing adequate spacing must be allowed for.

To facil itat e unrestr icted movement, th e upstand of th e bay is not fi rmly jointed with the vertical part of a build­ing. Where the bay width at the ed ge is not suff ic ient to make the upstand w ithout having to jo in on, wid er bays m ay be used, as also in respect of verges. How ever, the max imum per­m issibl e width of sh eets must not be exceeded. See 4.8.

Th e height of join tings to wal ls, roof pe­netrat ion s, chimneys, etc . must be re­lative to roof pit ch . App roxim ate valu es for height s are: Ro of pit ches up to 5° (9 %) - 150 mm minimum Roof pit ches of 5° (9 %) - 100 rnrn mini ­mum

To wate rproof the upper part against wind-driven rain , a flash ing strip (ca p­ping str ip) or a capping with a dripping edge is fixed on.

It is pointed out, however, that for many jo int ings the code of practice specifies a min imum height of 150 mrn .

Designers should allow for a minimum spac ing of 200 mm between roo f pene­trat ions and standing sea ms to en sure th at a professiona l jo b ca n be execu t­ed .

Eaves with hanging gutter, wit h or wi thout falls

--j

Ridge detail on monopitch roof Vent ilated ridg e deta il to mo no pitch roof at to RHEINZINKc wall c ladding verti cal wa ll

Double stand ing sea m roofing Batten roo f ing

Rid ge saddlcback roof wi th ridge ventuation and pr ote c tion 393 inEt dr ifting enow

32

Doubl e stan ding seam with verge detai l for roof sl op es 2 ~ 3° (5 %)

j\

30

Ang le standing seam wi th verge detail for roof slope s ~ ~ 22° (47%) ; areas with high snowfall ;;;;; - 35° (70 %)

Doubl e angle standing sea m with cap pi ng str ip and verge detail for roof slopes 2 - 25° (47 %J

German roll cap without wo od roll , wit h verge de­tail for roof slo pes > - 3° (5 %)

German roll ca p v.it h verge dotai: fo r roof slope s ;C, - - 3° (5%)

Balqian roll cap with vergp rlptAII for mnf ",Inrp", 2-- 25° -750

33

Hip Details

For good visual effect hips can be form ed in various ways as the illustra­tion s sho w. Welt ed bays converging on

Hi p de tai l with batt en hips can be finished only by means of a flashed batten or capp ing. The mini ­

sa i mum width for th e batten cappi ng is

about 6 cm; for cap ping with out a bat ­ten abou t 3 em.

H ip detai l with capping Where the hip is not emphas ized the bay welts must con verge at th e hip by means of a staggered arrangement. This arrangement is necessary, since otherwise the hip welt would have a 10-fold material thickness and a cor­rect fini sh would not be possible. Th is

Hip de tail with double requirem ent needs to be considered at s tandi ng seam

the plann ing stage.

Valley Details

\

The method of val ley forming depends firstly on the slope of the valley and secondly on its length. Therefore, th e constructional requirements for the various methods should be observed right at th e planning stage (see illustra­t ions). For shallow valleys of 7° (12%) a

Hip formed with doubl e sta nding seam and staggered into bay welts

recessed valley (va lley gutter) should be made . Where thi s is not possible for constructional reason s then, as th e last illustration shows, a valley with a tapering pattern of bays must be made.

Example: Hi p detail

For short lengths of valley, the so­called valley welt (with or without bat­ten) can be used , but th is is not easy to execute and, moreover, causes prob­lems when jointing to rid ge and eaves. Further, it should be noted that with long sheets, linear expansion in the valley welt cannot be accommodated sat isfactorily.

Toallow for linear expa nsion the length of the bays sh ould be limited to 6 m.

Vall ey with rece ssed valley gutter fo r pitc h <: 7° (t 2%)

Valley det ail with val ley bay for pitc h :5 25° (47 %)

Valley deta il wit h valley bay and supplementary we lt for pi tch :5 10° (18%j

Valley with bay s welt ed both sides

Valley with tapered arrangement

gutter

1

3 4

Concealed Roof Gutters

For co ncea led roof gutters downpipes must be dimens ioned and asso ciated with the relevant gutter cross-s ectio n in compliance with DIN 18 460.

For precaut ion ary reason s, however, two rainwater pipes must be installed, each of which must have the cross ­section calcul ated for on e downspout only. By this means one rainwater pipe can perform the full function of the other in the event of a blockage. This

..f

, 2

~

-,

I I.-I I----r ' -:-·~

i

arrangement for rainwater pip es as­sumes that the flow of water from downpipe to downpipe is not impeded by a conventional sliding gutter seam. I

Concea led gutter L I

I , IIt follows that an expansion piece must r r

with overflowbe used.This is the RHEINZINK expan­sion gutter. See 3.7.

The much -used practice, for reason s of safety, of doub ling the cros s-sectio n for concealed gutters is without measurable effect, as is shown by th e calcu lat ion in Section 7.1 .

Where the arrangement of two sepa­rate rainwater pipes is not possib le, th en, to gain space for an emergency overflow, the upper edg es of the gutter must be turn ed up suffic iently high to permit the backflow to dra in off freely without pen etrating into th e building, where an overflow gutter cannot fulfil this function.

IThese essential precautions must be Concealed gutte r , ,1.. 1

planned in at the de sign stage. with ove rflow gu tter

,,

, r 1 l..,~--- - __ , ..

Conce aled gutter , hallroun d v.... lth overfl ow gutter ' . .

35

------

- - - - - - - - -- - - - - - - - - - --- - -

Side Flashing to Walls Side flashing to walls adjoining RHEIN­~ I NK® roof covering is exemplified in th e illustration below.

Ex ample NO.1 . Capp ing strip with inset section

Example NO. 2 . Screed with wedged -in capping stri p

Both methods are distinguished by their simplici ty and reliable function .

The jointing section and rendering edge tr im can be fixed independent ly of roofing progress. For lateral height see 5.2.

Side flash ing to wall with dou ble standi ng seam Sid e flashing to wall with rendering and wedg ed ­decking with capping strip in sec tion in capping stri p

5.3 Penetrations in RHEINZINK® roofing Penetrations for chimneys, hatches, roof windows, vent pipes , snow guard su pports, etc ., must be made rain- and snow-proof by soldering, welting or double welting. The method of jointing is di ctated by the roof pitch . The safe

r

~~~ ~

- .•. . . . . ?'i . ... '1 -:1

j I :1

i ••.•I· ·1 I I I I I I

__ .~_1 '" - _. _... \

:J

weathering of penetrations with roof pitches below 7° (12%) can only be achieved by soft solde ring.Weathering above and below the penetration to the bays is made by double cross welting.

Where roof openings are of a width greater than 1 m, the back gutter junc­tion is to be made in wedge or saddle form .To improve rainwaterflowthe up­

per seam is formed ob lique ly to the eaves line .

.-­

~ I ~ I

-­-

i=="'"' ~~

--------- ,

D~ ~

r ! --------.

rJ

II ,'-J c-­ 1

I, I

i

I

\( !~ .~ - - - - - - - - -r ....,~ - ­

\:) - ­

I~ _ .- I -~

Dom ed roo f light wea thering essernorm Chimnev fl il 'lh ing in welt ed fini sh Typ e RHEINZINK in so lde red fi ni sh

36

Rooflight upsta nd essernorm Type RHEINZINK The recentl y developed upstand fu lfils important c riteria:

Jointing height of 15 cm with timber frame (12x 15 ern).The refore, jointing in a RHEINZINK® welt ed roof is simple and complies with th e code of prac tice (15 cm heig ht),

Can be fitted at any tim e to the welted roof prior to mounting roof light.

The upstand has a vertical 5 cm edging, specifica lly shaped for the welted roof, which is resistant to wind -d riven rain at the upper jointing with the roofi ng and offers, mor eover, adequat e space for carrying out welting work.

The rooflight upstand with shaped rim is then plac ed on th e flash ed wooden frame and secured with sc rews and seals,

The colour of the roofl ight upstand is anthracite-g rey.

0 ·'--­I~

Rooflig ht essernorm Type RHEINZINK in welte d finish

Jointi ng to th e roo flig ht with covering fram e

150 mm

Rooflight essernonn Type RHEINZIN K - so ldered f in is h

37

Flashings to Skylights

Examples of Various Finishes

Skyligh t with ap ron , ch eek and back gutter ju nct ions

Roof wind ow s in sea me d work w ith co ping fram e Skylig ht, up per join t w ed ge sha ped above

Skyli ght in pitche d roof , recessed, soldered Sky l ig ht in p i lc hed roof , so ldered in we lted ro of Skylig ht in welt ed fini sh

38

Chimney Flashings Chimney Claddings Roof Penetrations

Examples of Various Finishes

Chimney flue c ladding inserted within seam spactn q

Shaped chimney cla dding in special fi nish Cladding of glazed lantern light in seam tec hnique

--=­ .r­ ',--­ ,.­ . ­ --=---,­ -~ ~

-r--r!"': , ­~ ~ ~:::;:--

~:r±T~ ~~ --- ;'-,q~

Ch imn ey c lad ding integ rated into roof area Detail : Side jo int in curved form

Wedge detail to back gutte r of chimney stack

Roof penetration in solderedtechnique

39

Roof Dormers

Examples of Various Fin ishes

Row of roof dormers with prono unce d fasci as co rres pond ing to eaves cornice/ridge de ta i ls in ang led standing seam sys tem

'" ~ ;;;--­~- " --~

- '~';~ ' ,~

~...-::--

Roo f do rmer as co ntinuation of ver tical emphasis into the roof

Gabled dormer of de liberate ly simple design Systematic co ntinuatio n of eaves design as fas- Vertical patte rn of sea ms of th e dormer fasci as cias to the dormers co nti nued as window mullions.

Splayed join ts of the fasc ia executed as seams Successfu l jux tapos itio n of va rio us do rme r Round do rmers in ang led standing seam w ith forms c ross welts

40

5.4 Facade Cladding As with the technical procedures for roof cover ings and weatherings using RHEINZINK®, exter io r vert ical cladd ing must also be exec uted by the standing seam and roll ca p methods.

Logically th is area is not contro lled by guidelines fo r faca de cladding with and witho ut subst ructure. As soo n as DIN 18516 - Ext erior Wall Cladd ing, cur­rently und er discussion, has been ap ­proved and finalised, the guidel ines will be withdrawn. DIN 18516 E, part 1, July 1982, also does not envisage a specificat ion in respe ct of the standing seam and roll cap methods.

It must not be assumed, however, that good pract ic e for cladding exterior walls is not influenced by this standard. There are overlapping rules which must be observed.

DIN 1055, sheet 4 and ancillary regula ­tions apply in resp ect of wind loads. Where the c onstr uction of the facad e Fig. 1

will allow settlement of snow or the for­matio n of ice, loads must be cal culated in accordance with DII\J 1055 , sheet 5. For sloping walls loads must be calcu­lated as for roof coverings. See 4.6.

To secure to the substructure, the same rules as for roof deck ing apply to RHEINZINK" wall c ladding ; however, special con struct ions are po ssibl e. See 4.5.1 and 4.5.2.

Large areas of facade which are clad by the stand ing seam system, some­times do not look very attractive where long panels are used (not to exceed 6 mas this leng th is not suitable forwork on scaffold ing) .

Fig. 2

To impro ve appearance , the indiv idual - ..... IP"" ­.­

J-~lengths can be mounted with cross

---I1­ -r­. ~-~-welts in a symmetrica l pattern. By this method a smaller sealed effect can be achieved. Se e f igure 1. '- ­ -'- ­ --Creative effe c ts can also be achieved ,- ­e.. ­ o- ­ 1 ­by a diagonal arrangement of the panels, see figu re 2, or by a combina­ e-

r-r-r-­tion of variou s length joint s, for ;---, --- -instance by a rhythmic alternation of batten and angled stan ding seams F- J i

~i~ u~e ~L __.__. _ _ ~lR..l.

The preferred vertical jo inting method is the wider angl ed standing seam, which, as we ll as ensuring accuracy of line, (se e secti on 8 - seaming pliers) emph azises the verticals more strongly.

A special kind of verti cal jointing is th e doub le angled stand ing seam which , when jo inted to wind ows, avoids the change from left to righ t of the single welt. See illustrat ions 4.1 and 4.2.

Fig . 4.1

Fig . ~ .2

Where the seams have been properly made with the right kind of machines, the .cuos.are almosj.Jnvlsibla _

41

Th e use of the do uble standing seam for facade c ladding is disadvanta­geous for techn ical reasons,as th e Fal­zomat ca nnot be used on the scaffo ld­ing because of its relat ive height In such cases the seams would have LO be c losed manually, whi ch from a vi­s ual aspe ct could affect the st raight lin es of th e seam. Section 8.

Width of panels and thickness of material

Facade cladding is not merely installed as weath er protection for exterior walls, but also to create a pleasing ar­ch itectu ral effect. For th is reason the criteria regarding unit spacing and me­tal thickness are different from those for roof decking.

RHEINZINK® is a thin gauge material which when laid in bays does not have an absolutely plane surface.Therefore, to improve its visual effect a unit spac­ing of 500 mm is recommended and for panel lengths over 5 m, 400 mm should not be exceeded. See 5.

Raising the gauge from the usual 0,70 mm to 0,80 mm improves the visual appearance of the whole dueto greater rigidity.

Notes

Very great care must be taken when cladding facades, since every defect or omission will show. Prefabrication in the workshop of individual elements is essential.

Coupled with the special care that must be taken by the builder is the use of suitable tooling and machinery cur­rently available on the market. See 8.0.

It should be pointed out that in addition to the necessary fold at the base point, the panel at the upper joint must be folded over (water check) .

On the design side it mu st be borne in m ind that ventilation must be allowed for underneath a window sill (f igure 6) or parapet with the necessary overlap. The outer vertical flanks of this cover-

Fig. 5

ing must overlap the upper jointing of the panel, thus :

Height of building < 8 m > 5cm < 20 m > 8cm > 20 m > 10 cm

Fig. 6

Patination and surface

The chemical process which results in the protection film on the surface of RHEINZINK® (see 1.4) has several stages and may take a long time to develop, dependent on seasonal, weather and other factors. During this transitional phase, it has been ob­served that the surface seems to be ir­regular due to light reflection since, as has already been mentioned, thin gauge material never lies absolutely flat. With progressive patination these reflections will disappear; the greyish blue protective film will become denser and the colour more uniform .

Builders and designers frequently find this trans itional phase irritating as they feel it has a prejudicial effect on the overall architectural picture. For this reason only , RHEINZINK® has been pre-weathered (1.5) so that the transi­t ion al phase does not show.

However, the transit ional period up to completion of patination of the RHEIN­ZINK® surface shou ld not matter in evaluating th e material forfacade c lad­ding, as functionally and aesthetically it will serve its pu rpose for several ge­nerations.

A furth er, very important prerequisite for well executed facade c ladding with RHEINZINK® is not only a prec ise and clean preparation of the individual components by qualified experts, but also the orderly storage of the semi­products (strips/panels) and prefabri­cated components to avoid dirt and white rust.

During storage and transportat ion, no water must be allowed to pen etrate between stacked panels, strips or other profiles or co ils . It is a well known fact that in such ca ses of humidity and simultaneous exclusion of air; white rust develops on the su rface. See 1.4. This is a visual defect only but should be immediately removed by brush and a lot of water; as otherwise it will always be visible to a greater or lesser degree.

L

42

Roof in RHEINZINK'" doub le standi ng seam co v­ering. Facade in RHEINZINK' angled standing seam cl add ing. Details: Box gutter behind corn ice with function of ex­pose d gutter. Drip edge of wall c ladd ing above window lintel. Window flash in g with join ting to lower angled standing seam cladd ing or win d ow sill flash ing over facing brickwork.

Roo f and parape t apron clad in RHEINZINK" angled standing seam cove ring with co ncea led parapet copi ng. Detail s : Conc ealed parape t cop ing abov e slop ing sur ­face with inside fasc ia. Detailing of apro n curb with stand ing, visually co ntino us, seam. Lower edge of wall c ladding with weath ering to p lint h . Detai l : Sect ion of visually continuo us seam

Roof and parapet ap ro n in RHEINZINK"' angled standing seam covering with visibl e parape t cop ­ing : Details: Parapet co ping above sloping surface . Detailing of apron curb with standi ng, visuall y sep arated, seam. Eaves line of wall c ladd ing above window lin tel.

Illustration of parapet ap ro n wit h substructure, venti late d

Seamed parapet bays in ap ron cover ing Detail : Sta nding seam termi nus

Curb in apro n c lad ding with visu ally c ontinuous sea m

43

5.4 .1 Fire Protection

In accordance with building regula ­t io ns of the (German) Federal States special requirements may be laid down for fac ad e cladd ing with regard to their behaviour in ca se of fi re.The mand ato ­ry build ing material categ orie s B 1 or A corresp ond , together with th e a~tua l

surface c ladd ing of RHEINZINK , to subst ructures of cem ent- bonded wood c hipboard (1 6 mm) suc h as Duri­panel from Eternit. Various aluminium subframing systems are available for fi xing these Duripanel boards. Their suita bility for employment for thi s pur­pose IS to be ascertained either by re­ference to cu rrent regulati ons for tech­nical construct ions, or following com­ponent tests in the form of an authori ­zation. Included among the aluminium subframing systems, consisting es­sentially of wall anchors and fixing sec­t ions, and wh ich have proved them­selves in connection with Duripanel facade boarding, are the systems from Haase, Ickier and Wagner. Advice in th is matter can be obtained from the techn ical service of Eternit.

Between the Duripanel boards and RHEINZINK® cladding a separation membrane of PE sheeting is usually placed, spotfixed with a solvent-free contact adhesive. Alternatively, un­sa nded bitum inous felt or Duripanel impervious coating 250 g/m 2 may be used.

The fastenings are carried out with ri­vets, for example. Honsel, Alfo 5 x ap ­propriate length, rivet head diameter14 mm AIMg6.The boards are predrilled to accept the rivets.

Extracti on values in accordanc e with statical evidence for an already com­pleted object amount to 560 N/rivet with triple safety facto r. In order to pro­vide ge nerally valid da ta, ext raction values are being currently investigated by an independent institute and will be p ublished when compl eted.

The foregoing rules apply in equal measure for lay ing sh eet ing in bays.

Aluminiu m subfram ing, Wagne r System. Normal and abutted areas fo r cement-bonded woo d ch ipboarding .

Detail : Su bframin g with riveted woo d c hi pboard Dur ipanel with bu tt joints

Example : Municipa l Savings Bank, Dor tmund Desig n : Architects BDA Rick meyer & Saalkamp Roo fing contractor : Arge Aufderheide Gm bH, 4400 MOnster Kentzlc r Metall beda ch ung , 460 0 Dortmund

5.5 Snow G ards For th e safety of tra ffic, and depe nd ing on the degree of roo f slope and height , legally binding bu ilding regul at ion s may presc ribe me asures for protect ion against fall ing ic e and snow. These measure s ca n add it io nally serve in any fu rth er roof work to prevent accidents by slipp ing .

For RHEINZINK®double standing roo f­ing a sys tem has proved itself over yea rs in wh ic h a suff ic iently st rong tube (25 - 30 mm) is fix ed to the seam by mean s of two specially formed clamps (cf. ph oto) . The eff ectiveness of thi s system is based on the preven­tion of a thrust effect from the snow ly­ing on th e roof by th e binding eff ec t of

:"..

Exampl e : Rees snow guard system

th e tube in th e layer of snow, fr ozen snow or ice . The system has recently been co mplemented by ice guards fixed to the tubes (photo) to prevent the slipping of thin sheets of ice whi ch oft en rema in after a snow th aw.

Th e techni cal adva ntage of th is syst em lies in the fixing method wh ich avoid s penetrat ing the roo f skin, and th erefore allows the roof skin its unobstru cted th erm ally co nd it io ned c hanges of length .

In addit ion, the visu al restraint of thi s system provides fo r a pleasant appear­an ce in th e roofscape.

The clamp s and th e tub ing are ava il­ab le in specia l hard aluminium alloy, in

44

Comp lete Rees snow guard system wi th add it io nal ice guard

chrome-nickel steel and in galvanised steel, thou gh we do not recom mend the use of galvanised steel becau se the thi n laye r of zinc will be worn away over the years due to th e co ntinuous surf ace abraison. This results in rust­ing with subsequent drainage stre aks to the visual detriment of the roofing surface. In applying non-rusting mate ­rials attention should also be paid to using the appropriate non-rusting scre ws and nuts.

In areas of heavy snowfall experience shows that all tubes should be fixed at eac h seam ; whilst in the more moder­ate snowfa ll areas a c lamp to every second seam is adequate.

Tall c lamp fo r the second tube

Where necessary, severa l snow guards must be provided across the roof sur­face in acc ordance with the func ti on al principle described above (ct. pho to). Dependin g on the degree of roof slope and snow load ings a vertical spacing of 1.5 to 4 m shou ld be used.The applica­tion of double snow guards (tall clamps) at the eaves is recumrnenued in the case of widely cantilevered roo fs

to prevent masses of wet snow dro p­pin g into street areas. However, for structural reasons, the supporting effe ct of snow gua rds provide d at higher level is definitely required, especially in suc h cases. In so far as the snow gua rds in mode rate snowfall area s serve to relieve loading on the gutter system,as is frequ ently the case in northern Germany, a single snow guard at the eaves is generally ad­equ ate.Apart from this, th e question as to the necessary numb er of snow guards ca n only be answered by con­side ring each object individually.

5.6 Lightning Protection Owing to th e relatively good electrical co nduct ivity of RHEINZINK® special lightning co nductors need not be in­sta lled with th e doubl e standing seam sys tem. Onl y th e metal surface must be earthed in compliance with th e rel­evant specificat ions.

Exampl e: Earth ing be tween roof and gutte r

Example: Earth ing to ve rge

Example: Ligh tning co nductor at ch imney wi th earthing to ridge

45

6.0 Weatherings and Flashings In th e area of wea therings and flash ­ings RHEINZINK® is an exce llent com ­pl ement to the fun ction of ot her mate­rial s.

Ow ing to the good form abili ty and duc­t ility of RHEINZINK®, almo st any joint­ing wor k can be satisfactorily carried ou t.

6.1 Jointings For all jo intings to upper wall areas the angle strips must be formed at least 150 mm above the upper edge of the promenade roofing . For terracing or gravel chippings this can be some 200 mm and more. The upper edge of the angle strip is indi rect ly fixed with clips an d covered with a capping strip or fla shing to avoid wat er entering behind th e angle str ip. See 6.3.

The capping strip is turned into a groove or jo int in the wal l at a depth of 20 mm and fastened with hot dip galva­nised masonry (plaster) hooks, no me­tal sect ions or cover flashings with drip ed ge having to be used . There are other methods, but great care is need­ed with water-proofing (primer).

6.2 Weatherings a nd Flashings ­Hard Roofing Roofing of ti les, slate, fibre cement or si mi lar coverings is by overlapp ing of in divi dual roofing elements ; th is is not backfl ow-resistant and th erefo re a mi nimum roof pitch is requi red.

For pitches over 58 % (30°) the ind ivi­dual lengths of RHEINZINK® flash ings need not be so ft soldered; an overlap of 3 minimum of 50 mm suffi ces and the

~;;;;~~~::==::il

Eaves fin ish wi th projecti ng box gutter in accordance with DIN 18 461 and cornice flashin g with slate roof

The same method is applied in respe ct Flash ings for chimneys, roof wind ows of val ley gutters.A wate r check is fitted and to roof st ruc tures are soldered or at bo th sides and sho uld lie flush on a welted and, as usual , fi nished off with a recessed board . capp ing str ip . An expansion joint need

not be fitted so long as the length of a side does not exce ed 2 m.

- . o

o o

ends shou ld be grooved. Eaves finish wit h projecting gutte r in accordanc e with DIN 18461, with roo fing ti les

46

Valley gutter to slate roof

Valley detail as box gutte r fibre ceme nt roof ing (625 mm long - so -c alled "Ber liner Well e")

Verge with verge gutter and roof til es

Verge detai l with wall cladding coping ]II

Iii

47

6.3 Flashings for Built-up Roofs Rigid joints are made by turning up th e flat roof membrane. The sh eets to be jointed to vertical constructions must be fixed and flashed at the upper edge to make them rainproof

Th is is by meane of capping strips with or without clamp . Sealing can also be achieved by overlapping co ver ings , s uch as wall c lad d ing, parapet coping o r similar details.

Overlapping

Th e usual measures against penetra ­ti on of rainwat er and for fixing are not suffic ient. The turned-up membrane to vert ical construct ions must be protec t­ed against ultra-violet radia t ion and mech anical damage to avoid prema­ture ageing or destruction. Using RHEINZINK'" for this purpose fulfil s these protective requirements perma­nently. The RHEINZINK'J angle strip is formed in accordance with local requi­rements and is placed without a fixed joint on the turned-up roof felt , fastened and additionally held with clips. See 3.3.

The individual flashings can be fixed in standard lengths of 3 m.Thi s is done by 5 cm overlap joints . The joints are not connected, as no water-proofing fun c­tion is involved here .

To avoid any possible damage du e to sharp metal edges at the joints, th e ang le strip flashing on the roof edge is fold ed, so th at a c lip can be secured in it. For roofs with gravel ch ippings or c ement slabs , the lower edge of th e RHEINZINK® flashing should be at least 1 cm be low the upper surfac e of th e covering.

The height of the angle strip and the protection of the upper edge must be carried out in accordance with section 6 .1.

/

/

/

Capping strip w ith sealing rop e

Ang le str ip flashing as protoct ion again st ult raviolet radi atio n and mech anical damage, above the roof relt

48

Capp ing strip c lampe d into meta l section

-e-: Slop e of the plastering edge ­ 15°

/

RHEINZINK" capping str ip, lon g, as protection again st ultra violet radiation and mechanical da mage, with holder and metal section.

Capp ing strip turned into brick jo int with maso nry hook s

Bonding

Movable or rigid joints between the flashing at the water plane and pene­trating or bordering constructions are safely made by angle strips of RHEIN­ZINK® with out endangering the water­tightn ess of the roof sk in.

In the vert ical area the angle strip must be turned up at least 15 cm above th e surface of the gravel or concrete tiles.

The flange joint of th e angle strip must be at least 12 cm wide. For bett er adhe­sion of the seal, the f lange is painted with a co ating of solvent. The metal sur­face must be clean and dry .

The angle strip must be bond ed be­twe en layers. The fir st layer must be turn ed up on th e construction up to the upp er edge of the angle str ip . This complies with the requirements for a linin g between metal and masonry, ~.C? ~c!e~~_9!: _ l ~ I.~~ b~_lj~~e . ~ ~ N. 1.~. 3?9).

49

------_._._.__.._-- - - - - --- --- - - - - -- -------_.. ._-- - -- - - - - - _ .__.- -­

Further layers are fu lly bonded on the f lan ge of the angle st rip. The joint ing g roove is then further bo nded by means of a hot adhesiv e, dressing compound, or similar.

To accommodate movem ent , the tran­sit ion from metal to the firs t layer of the roof lining must be covered with a 10 cm wide separator strip, fixed on one s ide , before furth er layers are bonde d.

The angle strip must be fastened down to make it storm-proof. This precludes it from being placed directl y on th e in­sulation. A timber edg ing strip must be laid under the angl e strip, with a min i­m um proj ection of 4 cm beyond the angle st rip on the roof side for secure nailing.

The indi rect fastening of angle st rips by clips, batten s or tooth ed clips is abso­lutely necessary (exception RHEIN­ZINK System Type 1) to ensure that linear expansion of the angle st rip is not prevented.

Again and again one reads that the angle st rip is to be fast ened by nailing at 5 cm intervals. It could be con clud­ed, therefore, that direct fastening of the angle strip is permissible.

In contrast to the indirect fastening by clips, as described above, direct fas­tening prevents linear movement. A nailed angle strip, when bonded, is fixed like a locomotive rail. Therefore no forces can act by linear expansion on the individual soldered joints, and the soldered seam cannot break. On closer examination, however, this is not correct. The flange of the angle strip cannot be regarded on its own, for the vertical joint is not fixed firmly.

Here the forces of thermal movem ent beco me fully effective. The process becomes cle arer, the more note is taken of the fact that in bonding, linear expansion and contraction due to fluc­tuations in tempe rature, is impeded by direct fastening with nai ls at 5 em inter­vals, and thu s is equ ivalent to zero. In the vert ical zone , where there are no nail s, the change in length pe r 6 m of angle strip is up to 1.3 em. There is, therefore, cons ide rable stress. '

,A. roof temperature difference of 100 K (- 20DC to +80 DC) is assumed. When laid at a temp erature of +15DC , RHEIN­ZINK®will expand some 8.6 mm per 6 m length and contract 4.6 mm, See 3.6.

In th e lower temp erature zon e the angle st rip becomes too "short", Stress on the soldered seam may th erefore become so great that it cracks ope n. Stresses cause d by fluct uat ions in tem perature may cause the opening of the soldered seam to cont inue to the flang e and result in permeability The split in th e soldered seam may con ti­nue into the roof felt and cause it to tear.

In detail , the process can be explained as follows: By splitting of the soldered seam, a small gap of a few millim etres is created. Initially th is equ alled zero.

The rat io zero millimetres to a few milli ­metr es equals : infinity. As the roof felt is firmly bonded to the angle strip, this has the same ratio as the soldered seam . No material possesses unlimit ­ed elastic ity, It must break. Conse-

RHE II~ Z Il~ K expans ion jo int with bond ed angle strip

quent ly the crack in the soldered seam continues into th e roof felt

If theoretically th e roof fel t were bond­ed to c oncrete, a split would result like the so ldered sea m and th e same me­chani cal processes would become ef­fective . Therefore, the angle strip must be fastened indirect ly with clips.

The laying inst ructi ons in Sec tion 3.7 must be observed.

As a precautionary measure all angle strips or similarly bonded components in th e water plane should be bitumen­coated. In respect of terrace tiling in part icul ar, bituminous coating is es­sential, as air cannot reach th e moist zon e. See 1.4. In this case the protec­tive coating, commencing in the water plane, must be applied up to 2 em above the terrace tiling.

1 ,... ~ .: .. r--: ' 1 1 " . _

, 1 I .. . ~ ,

50

RHEINZINK Systems Type 1 Together with th e trade, we have devel­oped two sys tems for these angle joints , particularly for the joints in the water plane of loggias and terrac es.

The previously described require­ments for th e fastening of angle st rips and flashings or sim ilar bond ed join ts are fulf illed by a special process with co nsiderable advantages in handling and execut ion. Following a period of test s, patents have now been regis­tered.

As th e drawing shows, fastening of th e RHEINZINK(; joint s and cappings or angle strips to be bo nded is by nailing to the first layer of th e roof felt. Hot dip galvanised flat headed nails/d ecking tacks must be used.

In order to allow the play of forces through fixing by nails, certain provi­sions must be exactly observed.

Instead of nail holes as required for direct fastening, slot perforat ions are punched into the profile prior to us ing the RHEINZINK® angle strip. These should be about 2.5 cm from the roof­side edge of the angle strip to be bond­ed.

RHEINZINK expa ns ion joint wi th bond ed angle strip Typ e 1

The slot perforatio ns are parallel to th e longitudinal axis of th ermal expansion. The slot holes are 3 mm wide and 16 mm long. With a nail diameter of 2.8 mm, a 13 mm movement of RHEIN­ZINK® strips is pos sible. This is suf­fic ient for full y acco mmodat ing thermal line ar ch anges, as th e worked example , Secti on 6.3 "Bond ing", proves.The distance between perfora ­t ion is approx. 5 ern, i.e. once every 7 cm the RHEINZINK®str ip is held by a nail , and connection to th e edge or eaves board is made. For indirect fastening of bonded RHEINZINK® angle strips by nails in the area of slot perforation, a further provi sion must be obse rved.

The nail head must not press th e RHEINZINK®strip to the base because in th is way lateral movement of th e metal could be considerably impeded or even blocked. To avoid thi s, a metal strip 0.5 mm thick is interposed be­tween the nail and the edging board before impact which , upon removal , leaves suff icient play for movement of the RHEINZINK® strip. In accordanc e with the guidelines, every 6 m (or 3 m) a 1-head expansion joint is required. See 3.7.

, ' , ' I ' "

To balance out the diffe rent move­ment s between metal and roof felt, th is area is cove red wit h a slid ing st rip, 12 cm wide . The slidi ng st rip is made from 0.5 m m thick RHEINZINK® and fixed by a few nails on the roof side, but no adhesive sho uld be applied to eithe r side . Due to all th ese steps the usual rise in th e roof felt where it meets the metal, caused by we lts, c lips and 4 mm thic k sliding fe lt , is almost totally avoid­ed.

Impairment of water flow in the jointing zones to vertical structures as well as at the eaves is avoided, so that there is pract ically no danger of ponding on flat roof s.

The second and third layers of the roof fe lt are fully bonded to the 12 cm wide RHEINZINK" strip flange. Prior to th is a coating of so lvent is app lied. For thi s th e material must be clean and dry The precaut ionary prot ective coating of the angl e str ip, see 2.6 and 6.3 "Bonding" last paragraph, is carried out as des­cribed.

Bonded angl e st rip with 1-head dilato r (expan­sion j o int)

51

RHEINZINK Systems Type 2 For jo ints to vert ical constructions we have introduced a system for fastening the bond ed RHEINZlf-.JK ang le strips. This is distinguished by the fact that plumbing work can be ca rried on inde­pendently of the roofing work, as soon as all layers of the roof co nstruction below insulation level are laid .

By fastening the RHEINZINK® angle strips with RHEII\JZII\JK anchoring sec­tions, the otherwise necessary edging board used as a support for nail s wh en sec uring clips can be omitted.

RHE INZINK anchoring sectio ns are U­shaped as shown in the drawinq, Th is section is placed with its op en side to the cent re of the roof on the insulation lining.

Th e shank of the RHEINZINK anchor­ing section is fastened firmly by the usual means and bonded with the substructure bearing the roof felt. Th e c lea r height of the U-shape corre­sponds to the insulation thickness.The edg e of the RHEINZINKanchoring sec­tion is already turned up 120 0 at a width of 20 mm at the upper free shank and, aft er laying the RHEINZINK angle strip,

/

is folded down as a cli p to form a finis hed sing le welt.

The RHEINZINK anchoring sect ion is 0.8 mm thi ck . Th e fixing screws should be spaced abo ut 25 cm apart. There are sl its in the up per edge of the vert i­cal web . By thi s means jointing of the vapour pre ssu re expansion layer with the roof edge is obta ined. The lay ing and fast ening of the ang le strip and th e so lde red 1-head dil ators can follow in­de pendently from any further roof seal­ing work .

With the RHEINZINK®angle strip with a 17 cm wide flange, the RHEINZINK an­choring section is mounted with a 14 cm c lear dist ance from the vertical construction to be flashed, so that after covering with the separator strip the flange is 12 cm wide. The space in be­tween is filled with insulating material in accordance with the predetermined thi ckness.

Prior to mounting the RHEINZINK® angle strip, this area of weathering is covered with the first layer of the roof felt. This is bonded by spot application, or may be laid loosely. Fastening of the RHEINZINK® angle strip by the single welt allows thermal linear movement. Ac commodation of this th ermal ex pan­

RHEINZINK - 1-h ead di lator wit h bo nded parap et jui nt and parapet wea the ring

sion is by means of 1-head dilators , see Sec t. 3.7. The separator str ip over the tran sition metal to roofing felt, is placed in posit ion as des c ribe d. Thi s can also be don e in th e subse qu ent roof sea ling work. The roof felt is bonded on to th e specially prepared flange. In accor­dance with th e cod e of practice the angle strip mu st be protected up to a heigh t of 2 c m above the finish ing layer by an appropr iate dense coa ting. See Sect. 2.6

Correct arr angement of RHEINZINK expansion joints (d i lato rs) 3 .7.

52

Eaves detail - f lat roof wit h gravel board and RHEINZINK expans ion joint

6.4 Eaves Flashings 1. Eaves fla shings fo r roof coverings

2. Eaves flashings for metal roof s

3. Eaves flashings for roof sealing - bo nded into t he sealing felts - as a su pport for roof sealing

1. Eaves flashings for roof coverin gs. In tiled or slated roofs, the flashin g can also serv e as a drainage areawh ere the covering does not project over the rear edge of the gutter. Th is flashing can be fixed with a loose 5 cm wide overlap.As a precaution, the joint edges in the water plane should be lightly grooved to avo id capillary suction. The seating width on the eaves board depends on the type of roof covering and roof slop e. See 6.2. Fixing is by galvanised nails.

section wid th mm

> 240 250 200 16 7

Min. Thickness mm

0.80 0.70 0.70 0.70

Eaves deta il w ith proj ec ting gutte r in accorda nce wit h DIN 18461 - tiled roofing

2. Eaves flashings for metal roofs Eaves flashings for metal roofs are a special product. See 4.9 .

3. Eaves flashings for roof sealing - bond ed into the sealing felt.

The same provis ions apply to laying, fast en ing, bonding of individual length s and inclusion of expan sion joints as for bonded angle strips. See 6.3. The eaves board should be 1 cm thinner th an th e insulation to avoid pud dle s.

- as a support for roo f sealing

The flashing assum es anotherfunctio n where in "cheap roofing" reinforced st rips or th e roo f seali ng itself can be dres sed over the outer edge of th e eaves .

Here the flashing has a supportive rather th an a weathe ring functi on whi ch is exercised by th e roof sealing felts. Watertight jointing with the indivi­dual lcnqths L~ U1 -, r,~\"'","'"cll y. A G \jIll

overlap is sufficient. Th e flash ing is

53

fi xed directly with galvanised nails in a sta ggered arrangement at 5 cm inter ­val s. The bond ing flange is 12 cm and is painted with a solvent for bett er adh e­s ion of the roof felts. Here also the eaves board should be 1 cm thinner th an the insulation.

Of course in th is method the laws of physi cs concerning th ermal expan­sion are not canc elled out, but becom e effe ct ive along the seam of th e loose ov erlapping This movement must not be tran smitt ed to the bonded roof seal­ing , as otherwise th e elasti c ity of the roof felt would be over-stressed and break. See 6.3. Therefore, the loos e seams of two eaves flashings must have an unbonded zone of 15 cm on both sides instead of the otherwise ful­ly bonded felt. Where the roof sealing is by roof felt or welded bitumen sheets with glass fibr e, then the first layer in the eaves flashing zone must have an additonal bituminous cloth/fabric fla shing or equivalent, as sheets with glass fibre cannot be folded down into the gutter on the front edge of th e eaves flashing strip.

Th e use of the eaves flashing strip as a support should be restri cted to small, very simple and undemanding ("ch eap" ) roofs.

RHEINZIN K-Detail : Eaves flash ing strip bo nded with roo f - indi rec t fasten ing by c lips

RHEINZINK-Deta il : Eaves flash ing st rip as sup port, fi xed direc tly with nail s, with bo nde d cover strip

R;: .,I ·C~ LJ

~ -CCr ~ ,~

-CtV

{)Ic6.: .,

w '-.~.

c

I .r=p ~

y".y \ 1 .,i \~ LJ\;\ -l~

~ ,1­RHEINZINK" prod uc tion programme - eaves flash ings

54

6.5 Weatherings

Parapet co ping and angl e strip joint

Cornice, wall or other copings are indi­rectly fixed by sliding clips or strips to allow for thermal Iinear movement. The spacing of the ind ividual fasteners depends upon the construction, local requirements and wind load. See 4.7.

The overhang of the metal flashings is made with a drip edge with a distance of 20 mm min. from the construction to be protected (DIN18 339). An overhang of 30 mm is recommended .

Every 8 m or, measured from the edges, every 4 m, an expansion joint must be provided. Expansion can take place by means of a flat sliding seam expansion joint or an additional weathered under­lay with open joint.

Metal thickness re lat ed to sectio n

Sec tion width Min . Thickn ess mm mm

up to 167 0.6 5 up to 333 0.70 up to 400 0.80 up to 600 1.00

"f~

A+A,,Sect ion B-B

r - -, I -, : I: ~ } *, A,

~ A Section A1 - A1 I Covering in

acco rda nce with gu id elin es for flat roo fs

10 mm >-----< I i

Sectio n A-A

Various possibilities with RHEINZIN K:' parapet copin gs

II

II

L/ Section C - C

~~~~~

•.j . •' :' '- • ': \:~ ~: ." . ~ " ' , : . '. ~- ' .: " •

R H E INZI NK~w indow sill cover with wood en wi n- RHEINZIN K"' wintl ow sill cover with wooden dow fra mes and -side upturn to rend erinq fram8:;'

55

wall copings ; roof edges outs ide water Compensation for plane ; internal recessed, unbonded

Expansion gutters ­To co mp ensate for th ermal linear Sec tion larger tha n 500 mm 8 m [~] movement, an expans ion joint has to be made without causing permeability.

The appro x. value for max. spac ing of exp ansio n joints is as follows:

RHEINZIN K" wall coping with edging strip

RHEINZINK~ wall coping with edging strip and flat slid ing joint Vert ical face : Possibility 1.

Sec tio n B-B

10 mm

n

Section A-A

RHEINZINK" wa ll coping with edging strip and fla t sliding join t Verti cal face : Possibi lity 2.

10mm

!

Sect ion C-C

56

RHEI NZINK~ wa ll copi ng bonded fully with EN­KOLlT, jo int area with underlay butl joint 5 mm for 3 m indiv. len gths Can also be used fo r win dow sill cov er

A

Section A-A

RHEINZINK" wall coping with RHEINZINK ex­pansion joint and joi nt cap pi ng

Sec tion A-A

57

7.0 RHEINZINK-massiv Roof Drainage General Code of Practice - VOB - DIN Standards

Terminology, Calculation and Dimen­sions for roof drainage are defin ed in two DIN Stan dards.

Th ese are:

01N 18460" External rainwater pi pes on buildings and gutters . Terminology and Princi ­ples governing Calcula­tion

DIN 18461 * Eave s gutters, exte rna l rainwater pipes and fit ­tings made of met al.

* Published Sept. 1978

7.-',

Peak loads in a brief unit of t ime and their frequency are esse ntial factors in calculating roof drainage.

The frequ ency (n) rep resents the num­be r of exces ses per annum of defined vo lume of rainfall , e.g. n = 1 means th at a measured peak load is exceeded once annually.

The peak loads of some cit ies are sum­mari sed in Table 1.

Tabl e 1. Peak Load : Rainfall r fo r n ~ 1. T ~ 5 min.

Tab le 3 Drain age coeff ic ient ')

Type of adjace nt 41 Drainage ro of area coeffic ien ts

Roofs > 15° (27%) 1 Roofs < 15° (27%) 0.8

Roo f garde ns 0,3

' ) Extract from DIN 1986, part 2 (Issue 1978), Table 13, Drainage coefficients for determining rainwater drain­age Or:

DIN 18 460 (Iss ued 1978) Table 4 shows the pr ecipitation area in respect of rainw ater pipes in compliance with DIN 1986 (Drainage installations for build­ings and land) Part 2,Table 11, with local rainfall of 300 I/(s . hal .

For int ern al recessed gutters the downpipe and co rresponding gutter cross-sections must likewise be dimensioned in accordance with DIN 18460.

As a precautionary measure, however, two rainwater pipes must be installed,

Calculation Calculation of rainwater pipes and also associated gutter size depend on the amount of rainfall, effective roof area and drainage coefficient (pitch, nature

Tabl e 2, Rainfall for Germany for : n ~ 1; T ~ 5, 10 & 15 min , of surface) .

City I/ (s ' hal I/( min . rn") City I/ (s' hal I/(min ' mO)

Augsburg Bonn Fran kfu rt/M ain Kar lsruhe

333 532 370 53 2

2.00 3.20 2.22 3.20

Kassel M6nch engladbach MOnchen-Pasing Rotenburg/H ann .

203 300 416 490

1.22 1.80 2.50 2.94

Calculation of rainwater pipes and as­soc iated gutters is based on th e cross sectional areas calculated from the c lear dimensions of the profiles carry­ing the water. In rainwater pipes of rec­tangular cross section the smallest side must be at least equal to the dia­meter (nominal size) of corresponding rainwater pipes of circular cross sec­tion.

Because of the greater pollution hazard in gutters, rainwater pipes are dimensioned for rainfalls of at least 300 I/ (s . hal to prevent the ingress of precipitation moisture from the gutter into the building .

Te rminology and Principle of Cal cuia­ti on

Rainfall (r) is th e measured quantity of rain per unit of time in relation to area in I/ (s ' hal. Rain volume is defined as rain intensity measured in relation to dura­tion.

Duration of T rain 5 10 15

I/( s ' hal . mO)I/ (min I/ (s' hal I/(min ' mO) I/ (s ' hal I/(m in 'mo)

N. W. Germany 154 0 ,92 110 0 ,66 85 0,51 North East to Centr. Germany 162 0.97 121 0.7 3 94 0.57 West Germany 162 0.97 124 0.75 96 0.58 Saxo ny/ Sile s ia 174 1.04 132 0.80 106 0.64 So uth West Germ. 2 12 1.28 150 0.90 119 0.72

Further definitions are: Rainwater discharge (Qr) defined as the volume of water per second flowing into rainwater pipes (l/s) .

Rainwater flow (q.).Rainw aterflowas a factor of area in I/ (s . hal .

Table 2 shows five main regions of Ger­many with different climatic conditions and average rainfall.

Discharge coefficient ljJ Factor: Ratio of rainwater flow to rainfall (Table 3) .

Q (I/ s) = area (ha) . Rainfall I/ (s . hal . Discharge coefficient lV .

each of which must have the cal culat­ed cross section for only one outlet. Thus in th e event of a blockage, one rainwater pipe can take over from th e other. This ar rangement of rainwate r pip es assumes that the flow from rain­pipe to rainpipe is not blocked by a conventional sliding seam .

Therefore, an expansion joint situated in the flow must be used. RHEINZINK 'T

!

expansion joint ­ see 3.7.

The usual pract ice , for precautionary reasons, of doubling the cross section of recessed gutters rema ins without proven effect, as is demonstrated by calculation at the end of Ch apter 7.1 .

58

Table 4 Calc ulating rainwater pipes wit h c ircu lar cro ss section and related half- roun d and bo x- shaped metal gutt ers (see DIN 184 61) (Extract from Table 11 DIN 1986, part 2, Issue 1978)

Effe ctive roof area

with max. rainf all r : 300 I/(s . ha)")

m'

, rainwater

d rainage' )

Qrzul

l/ s

Rainwater pipe

Diam. Cros s ON sect.

mm ~ em'

Nom . size

Haif -rd .

gu tter c ro ss sect.

- em'

Related gutt er

Box - shaped

gutter cro ss Nom . size sect.

- em'

37

57

83

150

24 3

270

44 3

1.1

1.7

2.5

4.5

7.3

8,1

13.2

60')

70

80

100' )

120')

125

150 ')

28

38

50

79

113

122

177

200

-

250 285

333

400

-

500

25

-

43 63

92

145

-

245

200

-

250

333

400

-

500

23

-

42

90

135

-

220

*) Where local rainf all is greater th an 300 I/ (s . hal. corresponding values must be calculated (see example) ') Usual nom inal sizes for roof dra inage ') The values indicated derive from funnel-shaped outlets.

Where an arrangement of two separate rainwater pipes is not possible then, to gain space for an overflow, the upper edges of the gutter must be sufficiently high to permit the backflow to drain off without entering the building, in so far as an emergency gutter does not per­form this function.

These essential precautionary steps must be considered at the design stage.

It must be noted that when calculati ng external roof drainage on the basis of the above criteria, it is not the gutter cross-section which is calculated, but the required diameter of the drain pipe as a closed pipe. Of importance is only the size of the pipe cross-section for safe drainage of water; the gutter is merely related to the size of the pipe, as it only delivers water to the pipe as an open gutter.

In accordance with DIN 1986, part 2, 4.2.4, calculations for dimensioning rainwater pipes are based on funnel­shaped outlets. This means, however, that with cylindrical outlets commonly in use, the rainwater pipes must be one dimension larger. If, for example,Table1 indicates a rainwater pipe dimension of 100 fo r Or = 4.5 li s , a nominal pip e di ­

mension of 120 mm must be selected when using a cylindrical outlet. This can be readily seen, since with a straight, angular downflow, due to con­traction, the effective pipe cross-sec­tion is reduced to about 60%.lnstead of a DN 100 pipe, effectively it is only DN 80.

For this reason DIN 18461 has stand­ardised funnel-shaped outlets, so as to comply fully with the requirements of DIN18460 as well as with the principles of calculation in DIN 1986.

The gutter opening must be oval, about 30% larger than the cross-section of the pipe and the edges must be flanged downwards.

For recessed gutters the use of funnel ­shaped outlets is essential. If cyl indri­cal outlets are nevertheless used , one does not select the calculated value , but the next higher standard nom inal width in Table 4 to ensure the preven­t ion of possible backflow.

Ft-H3r'.-Z\!'II<'. ou 'ets ;',;!h I\.r oel-sh<l:;:ed .,le l R-ilNZiN-< 0C01ets I'l ith eyilnd·::;.aI rfl!e\ Ov-dl Pl.~lc · CDC~ ng - 30 % JarQC' IIV'l D'N 01'CUk1' j)l/. IC' ~rW1r;l- Ol'l p-oe

~oe

C<Y.1: f~ion 1/-~ - 1 Cont,a::'Q"lIl-~ - C.6'

EX<lmv.c: cal culation as per [)I N 1t14 tiU Funnel-3hnped outle l: Pipe dt.:lrn,,;,l(:l ON 100 Cylindfrc al ou tlet: Pipe dlamp.IW I) N 120

59

Th e following worked example de­monst rates the hydro-mechanical im­portance of a correct ly calculated rain­w ater pipe in re lati on to th e negli gible flow capacity of gutters.

Ro of are a to be drained Len gth of recessed g utt er 10 rn G utter c ross-section as in Table 4 Nominal gutter size 333 Capacity c ross s ection of gutter 90 drn" With rainfall of 300 I/(s . hal th e result is Qr inflow = 45 li s

By dividing the gutter flow capacity by the rainwater flow of 4.5 lis (Table 4) the time nece ssary to fil l the entire gut­ter will be obtained

20 s = 0.33 min.

This calculation proves that an ade­quately dimensioned downpipe is alone responsible for reliable roof drainage. Enlargement of the gutter cross section ~a s no measurable drainage effect.

Calculat io n examples:

Example 1 : (local rain fall up to 300 I/ (s hal

Rainfall r = 300 1/\s ' [; ' -) Effective roof area 12.5 m x 17.5 m A = 220 m Drain age co effi c ient (Roof ~ 15°) ljJ ~ 1.0

220 Rainwater discha rge Qr - - - - . 300 . 1.0

10000 Qr ~ 6.6 I/ s

from Tabl e 4 se lec ted pi pe for Qr ,.: 7.3 l/ s 1 downpipe nomina l size 120 mm

or, optionally, 2 down pi pes nominal size 100 mm

Example 2: (local rainfall r > 300 I/ (s ' hal Rainwater di scharge Qr = A . r . ljJ l/ s Rainfall e.g. r ~ 400 I (s hal Effective roof area : 12.5 m x 17.5 m A = 220 m' Drainage coeffi ci ent: (Roof 2.: 15°) ljJ = 1.0

Or =~ '4 00 ·1 . 0 10 000

Qr ~ 8.8 I/ s from Tabl e 4 se lec ted pip e for Qr ~ 13.2 l/ s 1 downpipe nominal size 150 mm

or, optio nally , 2 downpipes nomin al size 100 mm

~ : ~ Qj RHEINZINK nomogram for determining downpipe size as a factor of ,g .~ 0 ';;; roof area to be drained (DIN 18460 + DIN 1986)

Roof area to be drained

7.2 Jointing RHEINZINK-massiv gutters are jointed eitherfirmly by soft soldering or loosely by sliding seams.

By the soft soldering method the over­lap at the joints should be at least 10 mm, and the soft solder should cov­er the gap to a width of 10 mm horizon­tally and slightly inclined. In th e verti cal area in particular , the solder seam should be at least 5 mm. The det ails in Section 3.5 should be noted.

7.3 RHEINZINK-massiv Gutters The recent DIN Standard 18461 has added the box-shaped to the half­round hanging gutter. Omitted here is size 285, the reason being the very small cross sectional enlargement of about 15 ern? next to size 250. The 285 gutter is frequently seen in competition with the larger size 333, although it is really only a slightly larger size 250 gut­ter. The cross sect ional difference of approx. 48 ern" can be useful within the range of increasing sizes.

60

, 5

"" 22 - max. gu tt er ro ll (bead)

·- t ~ il< "> /\ --nf--- - --L.

Half-rd. gutter and brackets, sizes as per DIN 18461 Sizes in mm. Tole rance, w here not stated , ± 1 mm

Nom. II> rd. Gutter brack ets No m. Row

size Mel. with 2 springs FF with nosing & sprin g NF size

gutter sizes 1 2 3Thickn. verI. verI.

D d e f Acrn? s d1 a2 c1 c2 c2 d1 N ct c2 c2 b x s b x s b xs

200 80 ' 6 5 8 25 0.65 80 18 40 200 240 80 12 40 200 240 200 25 x 4 250 105 '18 7 10 43 0.65 105 20 50 230 280 105 14 50 230 280 250 25 x 4 30 x 4 25 x 6 285 127 18 7 10 63 0.70 127 20 60 230 290 127 14 60 230 290 285 30 x 4 30 x 5 25 x 6 333 153 20 9 11 92 0.70 153 20 75 230 300 153 14 75 230 300 333 30 x 5 40 x 5 25 x 6 400 192 22 9 11 145 0.70 192 20 95 250 340 192 14 95 250 340 400 30 x 5 40 x 5 25 x 8 500 250 22 9 21 245 0.80 250 20 125 250 390 250 14 125 250 390 500 40 x 5 40 x 5 25 x 8

d2 = 6 mm w ith s < 5 mm and 7 mm with s > 5 mm Front sp riil g with s ~ 4 mm 20 x 1.25 x 100 mm, with s = 5 mm 24 x 1.25 x 100 mm and wi th s > 5 mm 24 x 1.50 x 100 mm Rear sp ring with s < 5 mm 20 x 1.00 x 80 mm & with s > 5 mm 24 x 1.25 x 80 mm With s = e mm a2 becom es 5 mm sho rter Approx. values . See also DIN 1055 sheet 5

~i~L .L

11- t ;:,

I U

0 ~

I I

-l.

'----'C== = -=3I-- [ Box-shaped gutter and brackets, s izes as per DIN 18461 Sizes in mm. Tolerance, where not stated, ± 1 mm

Nom.. size

200 250 333 400 500 667

bo x gutte r

Sizes I Mel. ! Thickn I

I s

a b c d e A ern" min . a1

42 70 50 16 5 28 0.65 31 55 85 65 18 7 42 0.65 43 75 120 085 20 7 90 0.70 62 90 150 100 22 9 135 0.70 76

110 200 130 22 9 220 0.80 96 180 225 200 22 9 400 0.80 166

Gutter brac ket s Nom. Row size

with 2 sp rings FF . with nosin g & spri ng NF , 1 2 I 3

a2 b c1 c2 c2 a3 N b c1 c2 c2 bx s b x s bx s

18 70 34 200 240 31 12 70 34 200 240 200 25 x 4 20 85 46 230 280 43 14 85 46 230 280 250 25 x 4 30 x 4 25 x 6 20 120 65 230 300 62 14 120 65 230 300 333 30 x 5 40 x 5 25 x 6 20 150 79 250 340 76 14 150 79 250 340 400 30 x 5 40 x 5 25 x 8 20 200 99 250 390 96 14 200 99 250 390 500 40 x 5 40 x 5 25 x 8 20 225 169 260 390 166 14 225 169 260 390 667 40 x 5 40 x 5 25 x 8

b = Num. size. Basically : Gutter = b - 1 rnrn, bracket b + 2 mm d2 = 6 mm wi th s < 5 mm and 7 mm with s > 5 mm

Only w ith s = 8 mm a1 bec omes 10 mm and a2 5 mm shorter Front spring with s = 4 mm 20 x 1.25 x 100 mm, w ith s = 5 mm 24 x 1.25 x 100 mm and wi th s > 5 mm 24 x 1.50 x 100 mm Rear spring with s < 5 mm 20 x 1.00 x 80 mm and with s > 5 mm 24 x 1.25 x 80 mm Appro x. va lue s. See also DIN 1055 sheet 5

'lengt hened

61

As the tables show, exac t bracket sizes f or halfround and box-shaped gutters in finished bent co ndit ion are given. Thu s there are standardi sed brack ets for every size of gutter. For specia l applications the dimension c is length ened:

in stead of 200 240 instead of 230 280, etc.

Gutters are fixed to a fall. Hor izont al f ix­ing is possibl e, but great ca re must be taken to maintain an exact horizontal position, not only while fixing , but in the long term.

Gutters are also subject to th erm al mov ement. Bec ause of expansi on their lengths must be limited to 15 m, corners, e.g. in joints with angles, being treated as straight lengths. Long er gut ­ter lengths must be divided into dra in­age lengths. The conventional gutter sliding seam arranged at the upper fall is preferable , prov iding separation of the movable interlocking gutte rs by means of gutter stop ends with cap­ping or freely movable joint into an out­let at the lower fall. If possible the downpipe spacings should be adjust­ed to the maximum gutter lengths. For long lengths of gutter, the install ation of RHEINZINK exp ansion gutters as a ready-to-install unit is recommended. See 3.7.

For recessed drainage gutters, e.g. shed gutters, gutter length s can some­times not be redu ced by a closer arran­gement of downpipes.A subd ivision by mean s of stepped falls is not always c onstruc tively possibl e eith er.

The employment of the RHEINZINK c h loroprene expansion joint is a sim­pler solution.

7.4 RHEINZINK-massiv Downpipes DIN 18461 now differentiates between horizontal and vertical so ldered seams.

In the vertical area, int o which catego ry downp ipes fall, a sold ered seam width of at least 5 mm is required. Soldered seams in downpipes must be regarded with a degree of scepticism.

The frequently indifferent quality of sol­dering as well as the DIN stipulation motivated RHEINZINK to develop a RHEINZINK downpipe, soldered inter­nally, whi ch complies with the DIN re­qu irement for a 5 mm wide solde red seam. In this type of downpipe the seam does not break , not even du e to frost. Furthermore, the RHEINZINK downpi pe also meets cr itical aesthetic requirements.

VOB (DIN 18339, 3. 8. 9) spec ifies the fixing of the downpipe so that the seam is visible. This is for th e bette r co ntrol and repair of possible damag e to the

Round pipes

seam. For aesth etic reasons, however, the seam of a conventional downpipe should not be to th e front but to the side.

A remarkable extension to DIN18 461 is the standard isation of plug-in gutter out lets. These are in th e RHEINZINK produ ction programme. Two types are offere d : the st raight and the s lop ing plug-in outlets are manufactured as standard. With the funn el-shaped in­lets the requ irement s of DIN 18460, and thus the principles of calculatio n of DIN 1986, are fully met.

Round dow npipes. internall y solde red, and brac ket. Sizes as per DIN 18461

Diameter round pipes Metal Brack et

Dimen sions thi ckn. Diam. I Nail DW d A c m? s d I lverl.

60 60 28 0.60 60 120 76 45 0.65 76 120

80 80 50 0.65 80 120 200 87 59 0.65 87 120 200

100 100 79 0.65 100 140 200 120 120 113 0.70 120 140 200 150 150 177 0.70 150 140 20 0

Sectional d etail of mec hanica lly internally sol dered downpipe seam by th e RHEINZINK proc ess DBP 2607970

62

Nom. size

Oiam. Oia. rd.

pipe

Ou tlet, Form G, strai ght

Height I Put- inO. D. Width length ..-

Gutter openings ap prox.

val.

200

250

285

ON 60

80

80

d 60 76 80 80 87

d , 58 74 78 78 85

d 2

100

112

b 140 150 165 165 165

h 75 80 80 80 90

I 35 40 40 40 40

~ . - ,

I ; :­ I '

~r:~ 115/ 60 140/80 155/ 85 155/85 120/ 90

333 100 100 98 129 190 95 45 150/ 110 400 12 0 120 118 205 95 50 240/ 135

out lets, welded Form G, st raight, size In mm

Nom. Oia m. Dia. Outlet, Form S, slop ing Gutt er size rd. opngs .

pip e O. D. Wid th Height Put- in

appro x. val.

length

~~ON d d , d2 b h I (max.) 200 60 60 58 140 75 35 -i=_. -~ ~ - - - 11 5/ 60

250 80 76 74 100 150 80 40 / \ ' \ 140/ 80

80 78 165 80 40 \0· 155/ 85 80 78 165 80 40

.. \" t\

155/85285 80 87 85 112 165 90 40 120/ 90

333 10 0 100 98 129 190 95 45 150/ 110 400 120 120 118 205 95 50 240/ 135

outle ts, wel ded Form S, angled, sizes in mm

Diameter

DW

Diam. rd.

pi pe

d

Spigo t lengt h

c

Metal Thickn .

s min. (~er /

/1/~ -?~ ,

a ~ 40 0 ,600,720

R= d x 1.75 R = d x 1.35

60 60 30 0.70 76 35 0.70

80 80 35 0.70

100 87

100 35 35

0.70 0.70

120 120 40 0.80 150 150 40 0.80

Elbows for round downpipes, internally soldered sizes as per DIN 18461

Mechanical ly inte rnal ly soldered RHEINZINK elbows, 600, to the RHEINZINK

process, pat ent regist ered (DE-OS-29 39319).

The outlets deve loped for easy fixi ng not only ensure co rrect drainage, but are design ed for economica l mou nting, as well as being aes thet ically accep­table . The gutter ope ning should be oval and the edges flanged dow n­wards . The use of a wire foliage trap in the inlet to th e dow npipe is not recom­mended, as th is wil l hinder necessary maintenance.A screen over the sta nd­pipe fitted with a RHEINZINK pip e flap will prevent fo uling due to de ad fo liage.

Gutt er corner

Gutter corners, deep drawn in one piece, are newco mers to th e RHEIN­ZINK production pro gramme. The form of the external and internal corn ers exa ctly matches tha t of the associated stan dard gutter. Accurate retenti on of the rear raised wall ensures safe f low and prevents overflow damage. The rounded corners between the sho rt legs ensure perfect c irculation of water. Th e short leg length of the ang les com­pe nsates for ang ular variat ions on bui lding co rners.

63

Ho lderbat s of RHEINZIN K-massiv for rai nwa ter pipes with triple protection against corrosion.

o holderbat of RHEINZINKGl

o sc rew and hinge non-rust ing o distance piec e, angled or

threaded to cho ice, galvanised

T h is means :

o th e same weath ered pati na on rainwater pipe and holderbat

o no rust ing sc rews with unsigh tly rust streaks

o maximum durability

Eaves gutter brackets of RHEINZIN I(® sheated mantled with triple protection against corrosion:

o of hot-d ip galvanised steel o with RHEINZINK® mantled o two spring clips of stainless stee l

This means:

o the same weathered patina on eaves gutter and gutter brackets

o gutter spring clips non- rusting o maximum dur ability

Hol derbat with galvanised angl ed pin , non-rusti ng sc rew, bead and hinge

Eaves gutter brack et, RHEINZINK" mantled , for hal f-rou nd gutters, wi th 2 non-ru sting spring c lips

Ho lderbat with galvanis ed thr eaded pin, length 200 mm, non-rusting sc rew, bead and hinge

Hol derbat wi th galvanised threaded pin, le ngth 100 mm , non-ru sting sc rew, bead and hinge

64

8.0 Tools for Sheet Metal Roofing A prerequisite for professional work­manship with RHEINZINK materials, in addition to observing appropriate construct ional tech niques, is the em­ployment of suitable tools , machinery and ancilla ry equipment.

The most important tools and ma­ch ines for seaming work on roofs and facade are depict ed below

Shears

Straigh t seam ing ton gs

Tool s for seaming by hand

Eaves locking tool Eaves fol ding tool

Hol din g down tool Sta nding seam tool

Hardwood mal let Deck hammer

Cranked seamin g tongs Dec k tongs Seam open ing tongs (0130 cra nked. rv1c.uth d",~l1l ~ 18 ern)

65

Profiling and Seaming Machines, Machines for Bending Seams

Fo rm ing double standing seams with tools fo r seaming by hand and with a ha rdwood mallet is very labour-inten­sive. Therefore seami ng machi nes are employed, parti c ularly for large roof areas.

Machine for closing an angle standing seam

S t retching machine for producing curved ba ys with a fixed radiu s. Smallest rad ius 1 m.

Clos ing the double standi ng seam with the RHE INZIN K-F alzomat.

RHEINZINK- profi ling mac hine in act ion: var iab le cont inuously from 380 to 88 0 mm , with cutti ng facili ty.

The co nt inuous ly variable adjus tment is very important fo r facad e cladd ing because of diffe rent grid di mension s.

66

Profimat and Falzomat

Profimat and Falzomat mach ines have proved their worth in the produ ction of double stan ding seam roofs with RHEINZINK®strips. Even now it is only by th e comb ination of thes e two ma­chines that strips with an initial width from 380 to 880 mm can jointed by means of the double standing seam in only two operat ions.

Work proceeds qu ic kly , simply and economically . Naturally, all jointing to eaves, ridge and roo f penetrations must be carried out by co nventiona l means.

The Profimat has a sys tem of rollers by means of wh ic h the RHEINZI N ~ strip is simu ltaneously profi led on both sides. See 5.0 .

The profiled and cut bay is laid on th e substructure and fastened with special RHEINZINK sliding clips. These perm it the thermal linear expansion of the bays. ~HEINZINK f ixed clips prevent slid ing. In order to facilitate lateral movement , the strips are pre -profiled to give a 3 mm tolerance within the fi­nished double standing seam.

The profiled bays are interlo ck ed. The Falzomat with its roll er sys tem pro­duces the double standing seam in one operation. The Falzomat uses the pro­fi led upstand as a "rail" on which it automatically moves forward . See 5.0.

Prior to using the Falzomat the vert ica l upsta nd of the interlocking profile of the bay must be closed along a length of 30 cm by mean s of cranked seaming tongs and wo rked as a 20 cm doub le welt. Ths process sh ould be repeated at intervals along the preseamed pro­file to acc urate ly secu re the interlock­ing prof iles.

The Falzomat can be int rod uc ed or withd rawn anywhere along th e doub le standing seam. The moto r is switched off and a lever diseng ages the lower roll

The Profimat form s the two ed ges of the str ips to a profil e at the rate of 6 m/ min. The Falzom at c lose s the doubl e standing seam at the rate of 12 m/m in.

These capac ities clearly show th e eco ­nomic advantages of using Profimat and Falzomat machines .

RHEINZIN roofing areas

Handling instructions for preforming RHEINZINK® strips.

It is known from experi ence that the small co ils used in the t rade (from approx .100 kg), brigh t mille d and "pre­weathered" fo r roof coverings and facade claddings, ca n be unrolled eith er from the bottom or from the top , according to the pos it ion ing in the Pro ­fimat. It fo llows that either the milled upp er side or the mill ed und erside appears as fac ing surface. Th is further mean s that in the initial stage the ca r­bon ization (weathering) develops with varying intensity. The cause of the se temp orary differenc es in weathering is founded in th e milling process.

RHEINZINK® strips are regularly stretched to achieve optimum eveness and to obviate curved edges.

From these cons ide rat ions and also to provide th e mos t favourable conditio ns for laying, we have de cided in general to wind on the faci ng surfac e as the inner surf ace . In conseque nce, th is means for the roof-layer that th e small co ils always have to be unrolled fro m underneath, so that the correct fac ing surf ace is always laid uppermost.

Thi s proced ure offe rs in addition the advantage of bring ing the slightly con ­cave curved side of the bays to lay on the roof board ing and thus, togeth er with the locking of the seams , achiev­ing an almost fully flat surface.

Attention is here drawn once again to the fact that the flatness even of stretched sheeting can be impaired during laying. See 1.5.

In case of doubt, the fac ing surface can also be recognized from its appear­ance, being marred neither by punch marks nor adhesive tap ing. Punch marks and adhesive tape are always applied to the underside , not to the facing surface, of the strips.

RHEINZIN ~ "preweathered" always has as th e outside face of the coil the visually inferior surface, which is with­out subsequent treatment. Therefore, in this case too, always unroll from below for the pre-prof iling work.

For demonstration : Unr oll from underne ath onlv !

67

Seam-Bending ("Stretch-and-Com­pression') Machines

These machines facil itate the prod uc­t ion of curved joints. Addit ional pro­cesses such as heating, etc. are not re­qui red. The machine can be used fo r t he usual materi al thi cknesses.

Sea m bendi ng machin e for manua l work

Electrica lly powered stre tc hing machine

Example of app lica tion to barrel-vau lt roofs

Worki ng example : Stre tc h ing and compr essing to smalle r areas, e.g. dormers

. i .­ ~-~~~~ :

, . - t ; ~ . , . '" I

Working example : wall ascent: round

Exampl e of ap plicatio n to a " stun ted py ramid" wi th a curved transit ion to th e vertical

Sea ming Tongs for the Angle Welt

For aesthe tic reasons th e angle welt is often preferred to the double welt in facade cladding. The seaming tongs repro duced in th e photograph not only facilitate this wo rk, but a perfectl y straight seam is ac hieved. Normal' seaming ton gs can hardly produce an exactly st raight sea m. Therefore, seaming tongs sh ould be used only for short length s, suc h as cornices. For areas of c ladd ing us ing longer bays, the angle welt sea ming mach ine should be used, as bei ng more econo­mical.

Locking to ng s for ang le sea m

II Examp le involv ing the use of seam c losing p inc­ers

68

9.0 General Directionsfor the Specification of Items in Sheet Metal Roofing Technique and Roofing Contractor's Work Where th e descript ion of items of work in the bill of quantities or in the contract permits different interpretat ions, the contractor mu st indicate his preci se intent ions and oblig at ions not later than th e quotation date , i.e. prior to signature of the contract or, on being requ ested, bef ore this t ime.

Where the bidder or co ntractor find s variatio ns between th e terms of th e subm ission and works or detailed draw ings, this must be clarif ied wit h the proje ct representative prior to com ­menc ing work and the method of carry­ing out the work determined.

The contractor must take all dim en ­sio ns for th e execu tion of the work to be done. '

9.1 Notifying Reservations Befor e work co mmences, th e contrac ­tor must check that the project is one whic h he can car ry out. Querie s must be notified in writing with out delay

Obli gations for checking prelimin ary work by oth er contractors regardi ng suit ability are co ntained in VOB, Part B, DIN 1961 , para. 4 No.3.

10.0 Introductory Comments Regarding Quotations In the speci ficat ions which follow an at­tempt has been made to fo rmul ate c learly and exhaust ively, as far as pos­sible, the serv ices to be rendered in accordance wit h VOB Part A para. 9, and ampl ified by numerous drawings, so th at th e tende r is based on a clear, comparative description of services.

Prices include all materials and anc il­lary se rvices in accordance with the technical specificat ions for building serv ice s (VOB).

Examples of specificatio ns are c lassi­fied summarily, some being illustrated with drawings. Sentences or parts of sentences in brack ets are for informa­tion only. For the purpose of c larity some important table s have been sum­maris ed.

The relevant values should be inserted into the spe cif ication s.

Table 1: Strip widths & Metal

Height of Building

strip w idth

metal thickness

0-1 00 m 60 0 0.70 mm

0­ 20 m 700 0.70 mm

0­ 8 m 800 0.80 mm

Tab le 2: Pos it io n of fixed c lips as a facto r of roof pitch

in cent re of sheet

5%- 18% 3° -1 0° at upper third

18%-5 8% 10° - 30° at up per qua rter

58% 30° at upper end of bay

Table 4 . Cross seams for RHEINZINKfJ decking

Tab le 3 : Numbe r and spacings of clips in rela tion to he ight of building and least favou rable roof pitch (area of highest win d suc tio n loads)

Corner & edge areas Normal area Height of strip width /coordin. axes'" st rip width /coord in. axes " Building 600 /530 700 /630 800 /730 600 /530 700 /630 800 /730

m Him' cm/H Him' cmlH Him' cmlH Him' cmlH Him' c ml H Him' c ml H

0­ 8 4 50' 4 42 4 36 4 50' 4 42 4 36

8­ 20 6 33 6 28 5 40 5 33

20-100 8 25 6 33

Him' = cllps/m" cm lH = clip sp acings in cm • = max. c lip spacing (10m length of sec tio ns)

•• ­ width of bay c; unit spacing (coo rd inated axes)

Tabl e 5 : Double standing seam syste m Seaming loss for (Approx. values) 600 mm strips 01 %seam "lo ss" coord. 1O

extra height axis lo ss

25 80 520 13.3 15.4 90 17.7 30 5 10 15.0 Roll cap system 100 35 500 16.7 20.0

with 125 mm 110 49040 18.3 22.4 '-­

Table 6 : Roll cap sys tem (Approx. values)

batt en " lc ss" coo rd. % " 10

height ax is loss extra

8elg . 40 165 560 22.8 29.5 Decki ng 60 205 520 28.3 39.4 German 40 195 53 0 26.9 36.8 Deckinq GO ?1S dqn 32 .~ ~8 .0

69

Notifying Reservations Reservations are especially notif ied regardi ng: - unsuitable condition of the underlying surfaces, e.g. too rough, porous, mois t or

soiled - use of unsu itable wood chipboard ing on the facade:

e.g. phenolic- resin-bonde d, recommended isocyanate-bonded chipboa rd Type V100 G - ISO, min. 25 mm thi ck

- unsuitable boarding , e.g. insuff ic ient board th ickness (min. 24 mm), unequ al board thi ckness, e.g. eaves board for embedd ing gutt er brack ets (mi n. 40 mm)

- absence of or insuff icient means for fixing to joints, coveri ngs and c laddings - unsuitable position on site (alt itude or fall ),

e.g. of drainage facilities, jo ints and coverings - insuff ic ient space for conc ealed gutter, e.g. for necessary precautions (emer­

gency overflow, 'additional rainwater pipe, overflow gutte r) - insufficien t roof pit ch

e.g. strip decking min. 5%(3°) on all parts of the roof (eaves,dr ip,valley): recom ­mend ed 13 % (7°)

- diverqen ce from the hori zontal level or fall s as necessary on site - abse nce of recessing for eaves flash ings - non -provision of wedge/saddle above roof opening (bac k gu tter det ail) - use of RHEINZINK® and copper (contact corrosion) ; combin ation with alumin­

ium, lead, galvanised steel and stainless steel is possible - abse nce of prot ective coat ing of the drainage surfac es on eaves flash ings, gut­

ter s, etc . in combination with bituminous felts - absence of dense protect ive coating of the bonded angle strips up to a height of

2 cm above the layer - insufficient width of masti c flange (min. 12 c m, measu red with out the clip area) - insuff icient height of abutments (pitch < 5° z: 15 ern, ~ 5° c: 10 cm height abov e

the layer)

Drip edge: please not e!

height dim ensi ons of ke rb weather ing d rip edge b ui ld ing h i h. min. d istance

(rn) (mm) (rnrn) fro m co ns tructio n

:58 40 - 50 2: 50 20

8 - 20 40 - 50 2: 80 20

2: 20 2: 100 20

h i = up stan d of the bay , h2 = overlapp ing of th e kerb we athering over the co nst ruction to be protec ted

70

11.0 RHEINZINK® Practical Examples

2

71

Ir'I .

I i I

5

::

£ '

10

13 14

73

20

75