metsec joists

Lattice beam technical manualLightweight joists and trusses

www.metsec.com

CI/SfBSeptember 2008

(28) Hh2

486.2 Lattice Beams 23:Layout 1 2/10/08 09:50 Page 3

486.2 Lattice Beams 23:Layout 1 2/10/08 09:50

3

Product range 6-9

Roof beams 10-19

Floor beams 22-23

Ceiling and service supports 20-21

Metsec: Investing in quality and service 4-5

Features and benefits 6-7Product range 8-9

Metal roof systems 10-11Traditional roof systems 12Green roof systems 13Complete lightweight systems 14-15Eaves cantilever systems 16-17Over-roof systems 18Cradle support systems 19

Traditional floor systems 22Mezzanine floor systems 23

Fixing details 24-27

Typical fixing details 24-27

Chord and bridging details 28-29

Chord details 28Bridging details 29

Ceiling and service support systems 20Walk on ceiling systems 21

Design examples and load tables 30-37

Design examples 30-33Load tables 34-37

Services and design software 38-39

Contents

Services and general notes 38Software 39


4

Investing in quality and service

The CompanyMetsec plc is the UK’s largest specialist cold roll-forming company, providing structural steelcomponents for the UK construction andmanufacturing industries. We have beenestablished for over 75 years and are based inOldbury in the West Midlands.

Today, Metsec are part of the Profilform Divisionof voestalpine - the world’s largest manufacturerof cold roll-formed sections, with a globalnetwork producing over 800,000 tonnes of coldrolled steel per annum.

We focus on adding value through expert design,precision manufacturing and on-time, in-fullproduct delivery. Our aim is to provide excellentservice and quality products that offer ourcustomers cost effective solutions.

Metsec Lattice Beam DivisionLightweight steel lattice beams were firstintroduced by Metsec in the 1950’s and theirinherent advantages very quickly established theproduct as the first choice for structurally sound,cost effective construction.

Since this introduction, the Metsec policy ofcontinual research and development has ensuredthat quality and technical properties haveimproved over the years and availability of typehas increased in parallel with development inbuilding technology and architectural styles.

The Metsec Lattice Beam Division offers a widerange of joist and truss solutions pre-engineeredoff site. We can achieve spans of up to 40m andall of our designs give optimal levels of structuralperformance in roof, floor or any other applicationwhere light weight and long span performance isimportant. All sections are designed inaccordance with BS 5950-5:1998.

QualityMetsec operates strict design and qualityprocedures through a Quality ManagementSystem accredited to BS EN ISO 9001:2000 which covers both our design and manufacturingoperations.

This commitment to quality ensures that weprovide the highest levels of performancethroughout our operations, ensuring the highestlevel of customer satisfaction.

Quality and service


5

Quality and service

SustainabilityCertification

Metsec and voestalpine both regard the issue ofsustainability as a core social, as well ascorporate, responsibility.

This has been recognised by the award of BS EN ISO 14001:2004 for our EnvironmentalManagement System.

Metsec were the first cold roll-forming companyto be awarded the prestigious gold standardunder the Steel Construction SustainabilityCharter.

Additionally, Metsec recognise thatenvironmental responsibility is both a local aswell as a global issue. We were therefore pleasedto be awarded the Sandwell Borough PlatinumEnvironmental Charter Award following an auditof our Environmental management proceduresand award of BS EN ISO 14001:2004.

Design

Our market-leading LatticeSPEC design softwareprovides cost effective solutions to maximise thedesign efficiency of structures. Comprehensivetechnical support is provided by our designoffice.

The latest version of LatticeSPEC offers theunique advantage of producing completeprofiles/sections of joists and trusses in .dxfformat, saving the professional team valuabletime when specifying our products.

For full details on our technical support serviceand how to obtain a free copy of LatticeSPECplease refer to page 39.

“The baseline SPeAR® diagram shows a well balanced performance in terms of sustainability, and that Metsec is already meeting legislation or best practice in the large majority of areas. In some cases Metsec is starting to move beyond best practice.”

Re-use and recycling

Steel is one of the World’s most recycledmaterials. According to the British ConstructionalSteelwork Association (BCSA), recovery rates forsteel components from building demolition sitesare 84% for recycling and 10% for re-use*. This gives a total potential recovery and re-use factor of steel from buildings of anincredible 94%.

* BCSA publication no. 35/03

SPeAR®

Independently, as well as with voestalpine,Metsec will continue to pursue sustainability as akey business objective. The cornerstone of this isthe very thorough and detailed societal, economicand environmental sustainability review of ouroperations carried out in the SPeAR® (SustainableProject Appraisal Routine) Report from Arup.This report gives us both an assessment of ourcurrent environmental position as well asidentifying key areas for improvement in thefuture.

To quote from the report:


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Product Range

Features and benefitsMetsec lattice beams are designed andmanufactured to BS 5950-1: 2000 and 5: 1998 andare formed from two cold rolled chord sectionswith a central web joining the two together.Typical profiles are shown on page 8-9. Thechord sections are all formed from high yieldsteel to BS EN 10149-2: 1996 and have aminimum yield strength of 355N/mm².

The web members are usually constructed fromsolid bar on the smaller joists or hollow sectionfor the deeper joists and trusses. These are joinedto the chord sections by CO2 shielded arcwelding in a pre-set jig to ensure dimensionalaccuracy.

This process allows for the design andmanufacture of a vast range of profiles, fromsimple parallel joists through to complex doublecurve, wave trusses, to suit almost anyapplication.

Services - excellent head heightThe open web configuration of Metsec latticebeams allows for the simple passage of servicesthrough the web lacings. However, the weblacings will not necessarily align unless this isspecifically requested.

Where special duct openings are required theseshould be positioned near the centre of the beamwhere shear is less critical.

Please consult the Metsec Lattice Beam TechnicalDepartment for further information.

Long span - light wieghtThe open web configuration of Metsec latticebeams allows for the simple passage of servicesthrough the web lacings. However, the weblacings will not necessarily align unless this isspecifically requested.

Where special duct openings are required theseshould be positioned near the centre of the beamwhere shear is less critical.

Please consult the Metsec Lattice Beam TechnicalDepartment for further information.


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Product Range

Pre-engineered offsite - to ease site accessWhere site access is a consideration, bolted jointscan be used. The joists are then assembled onsite using H.T. grade 8.8 bolts to join the sections.

Flush site joints to the top and/or bottom chordsare also available.

Factory joints may occasionally be incorporatedinto joists. They will always consist of anappropriate jointing arrangement with a fullpenetration butt weld.

Finish – as flexible as your designAll Metsec lattice beams are supplied shotblasted and factory finished with a ZincPhosphate primer as standard. Other paintedfinishes, including any standard RAL colour, areavailable upon request. This feature isparticularly important if it is desired to leave thelattice members exposed as part of a ‘feature’internal roof structure.

A hot-dipped galvanised finish is also available.This is recommended for cold roofs and roofs withlimited access or exposed locations.

Timber - for rapid, secure fixingsFlush fitting standard ‘Vac-Vac WR’ treatedtimber can be supplied if required in the topand/or bottom chords of all beams. The timber isrigidly attached to the chords by shot-fired pins at600mm staggered centres. This offers a simplefixing medium for certain floor/roof finishes,timber firrings and/or plasterboard ceilings.

Optimised wall/ceiling junctionsDue to the slim profile offered by Metsec latticebeams’ excellent strength to weight ratio, beamscan be incorporated at the head of partitioningand drylinig systems without any requirement forseparate boxing in or encaement.

This allows continous and parallel studwork tofull ceiling height, simplifying and acceleratinginstallation, maximising use of space andoptimising aesthetics.


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Parallel beamRoofs – suitable for use with flat roofs or sloping roofs

where the lattice beams can be laid to falls. They can

also be used as long span purlins and are suitable for

use with most external finishes from lightweight metal

sheeting through to heavier constructions with tiles on

battens or decking.

Floors – suitable for use as joists in all types of flooring

including timber, pre-cast concrete slabs or profiled

metal decking with in-situ poured concrete.

Product range

Pitched trussPitched trusses are suitable for all types of duo-pitch

roof construction and can be used with most external

finishes from lightweight metal sheeting through to

heavier constructions with tiles on battens or decking.

Tapered trussTapered trusses are suitable for all types of mono-pitch

roof construction. They can be used with most external

finishes from lightweight metal sheeting through to

heavier constructions with tiles on battens or decking.

Inverted trussInverted trusses are generally used on low pitched

roofing with timber or metal decking and built up

finishes. When used in conjunction with Metsec

Z-section purlins the design of deep valley gutters can

be simplified.

Parallel pitched beamParallel pitched beams are suitable for all types of duo-

pitch roof construction providing extra headroom over

that afforded by the pitched truss. They can be used

with most external finishes from lightweight metal

sheeting through to heavier constructions with tiles on

battens or decking.

Product Range


9

In many of the applications listed above Metsec Z-section purlinsprovide an excellent design solution to carry the external finish.Similarly the wide range of Metsec mezzanine floor C-sections canprovide a range of system solutions for the designer.

Curved trussCurved trusses can provide an aesthetically enhanced

roof profile. When used with a standing seam roof this

type of construction is easy to detail and install giving a

very low maintenance roof.

Curved beamCurved beams provide an aesthetically enhanced roof

profile construction providing extra headroom over that

afforded by the curved truss. When used with a

standing seam roof this type of construction is easy to

detail and install giving a very low maintenance roof.

Double curved (wave) trussDouble curved trusses provide an ideal solution for the

designer working with modern multi-curved roof

structures. When used in conjunction with Metsec SFS

framing system the structure can be built to a constant

datum and can be used with all typical external finishes

Inverted curved trussInverted curved trusses offer designers a simple solution

when specifying a single curve roof structure. This can

be used to enhance the appearance of roof structures

and is frequently specified with standing seam roofing

to create a smooth appearance.

Product Range


10

Metsec lattice beams can offer the ideal solutionfor supporting a wide variety of roofing systemsdue to their excellent strength to weight ratio. A typical Metsec typical lattice beam can weighup to 50% less than its hot rolled counterpart andyet still achieve spans of up to 40m without theneed for intermediate support columns – whichcan allow designers greater flexibility whenworking to optimise internal space.

Internal space can also be optimised by passingservices through the web of the lattice ratherthan having to suspend them underneath causinga significant loss of headroom.

Metal roof systems

Curved truss with structural deckMetsec curved trusses can be used to supportstructural decks with a suspended ceiling. The natural open web of the truss allows for thesimple passage of services.

Roof beams

Leasowes Medical Centre, West Midlands

Similarly their aesthetic properties mean thatthey can be supplied painted and left exposed aspart of a ‘feature’ internal roof structure.

In addition to the direct reduction of theenvironmental footprint of a construction projectby virtue of their lighter weight, lattice beamscan also help to reduce the environmentalfootprint of the project by using off-sitefabrication to speed up the construction processof the roof as the lighter sections can generally betransported and handled more efficiently on site.


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Parallel beam laid to fall Metsec parallel beams can be used to support Z-section purlinsbolted to cleats pre-welded to the top chord of the beam. Liner tray,insulation and metal deck provide the weather-proof layer and arefixed to the Z-section purlins.

Pitched truss with flush-fitting Z-section purlinsMetsec pitched trusses are supported on a hot rolled steel structuralframe. Z-section purlins are fitted flush to the top chord of thepitched trusses to support standing seam roof, or similar.

Flush fitting Z-section purlins are often used to minimise theoverall construction depth of the roof.

Roof beams

Vauxhall Sales Centre, West Midlands

Staplehurst Medical Centre, Kent


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Roof beams

Parallel beam used as purlinMetsec parallel beams can beused as long span purlinssupported on load bearingmasonry walls. In thisapplication timber firrings arefixed directly to flush fittingtimber inserts in the top chordof the beam. Timber roof raftersare then fixed to the timberfirrings to support counterbattens, underlay, tiling battensand tile or slates.

Pitched truss used to supporttimber purlinsTraditional timber purlins canbe supported on a Metsecpitched truss. Ply or similarsheathing is then used tosupport weatherproofing layersof battens, underlay and rooftiles or slates.

Traditional roof systems

Firringsby others

Timber insert for nailability


13

Roof beams

Parallel beams used to supportsteel decking with green roofsurfacingMetsec parallel beams can beused to support a structural deck,membrane, substrate and Sedumroof.

These beams can be up to 50%lighter than hot rolled beams anduse far less steel with considerablyless environmental impact thanother systems.

Item 8

Smithswood School, Solihull

Green roof systems


14

Roof beams

Complete lightweight systemsMetsec lightweight trusses, combined with SFSstand-alone walling systems, are becoming evermore popular for constructing completestructures.

The Metsec Lattice Beam and Framing Divisionswork together closely to provide totalconstruction solutions for the developer.

Grange School

The complete wall and roof solution is frequentlyinstalled through the Metsec Framing Division’sapproved installer network. This adds to thecomplete, one-source nature of the package inkeeping with the demands of the modernconstruction industry.


Patching Lodge, Brighton

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Roof beams

Metsec double curve roof systemMetsec lightweight trusses and Z-section purlins can also becombined with stand alone, light gauge, cold rolled SteelFraming Systems (SFS) to provide complete one-sourcebuilding solutions.


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Roof beams

Cantilever bolted to weldedstub-postThis detail can be used formedium span cantilevers ofup to 2m.

The cantilever arm is boltedto the end post which issupplied welded into the endof the lattice.

Since the cantilever roofelement does not require aninsulation layer the line ofthe supporting cantilevereaves structure iscorrespondingly raised tosupport the top sheet.

Eaves cantilever systems

Top chord cantileverThis detail can be used forsmall span cantilevers of up to 1m.

Stiffener angles can be weldedto the sides of the top chord, ifrequired, to provide aneconomic cantilever solution.


Roof beams

Loose, bolt-on cantileverThis detail can be used forlarge span cantilevers ofover 2m.

The cantilever arm extendsinto the building to provide anadequate backing span and isbolted on to the top chord ofthe lattice.

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Park Central Apartments, Birmingham


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Roof beams

Over-roof systems

Where existing flat roofs are starting to fail orrequire upgrading, one option to consider is thecreation of a new pitched, or curved, over-roofwhich can be constructed quickly and costeffectively using lattice trusses.

The lightweight lattice over-roofing systemavoids the need to strengthen the existing roofstructure and can give an existing building amuch needed facelift - typically at a fraction ofnew build costs.

The new trusses can be spaced at much widercentres than other over-roof systems, whichresults in fewer penetrations and fixings into theexisting structure.

St. Lukes School, Portsmouth.

The new lattice trusses are installed to spanacross the building and provide a range ofbenefits for the building owner, includingimproved water run-off and enhanced buildinginsulation. The additional space created underthe new structure can also be used to housebuilding services making usable space availableelsewhere in the structure.

The Metsec lattice team have gainedconsiderable expertise in the design of trusses foruse in over-roofing projects both large and small.

Building services

Ring beams


Cradle support systems

The solutionBy avoiding the need to re-roof, with all the associated disruption and cost this may cause, thecradle support system offers a permanent solution in a more straight forward and cost-effective waythan any of the alternatives previously available.

“ Under the direction of Atkins project managers, the cradle system has been successfully installed within anumber schools in the Essex area over the past few years. The system has enabled the school to remain inoccupation at all times as the work is undertaken overnight with the majority of furniture, fittings and finishes leftin place but covered.

This has allowed the schools to continue concentrating on educating rather than managing the impact of theworks on their school and has been seen as a significant benefit by the client.”

Rob Moy,Senior Building Surveyor at Atkins

The unique Metsec cradle support system can beused to save flat roofs that are nearing the end oftheir functional life.

Metsec offers a simple solution to any Re-inforced Autoclaved Aerated Concrete(RAAC) plank roof where deflection is leading tolong-term structural damage to the roof. In thissystem a grid of lattice beams are fixed below theexisting roof and a precise air lifting system(PALS) is inflated to correct deflection. Once thedeflection has been corrected the void betweenroof plank and beam is filled with high density,non shrink grout to take the load.

This results in up to 50% lower costs than a newroof and allows weekend and/or night working,minimising disruption.

Ponding water resulting from deflection

Deflected RAAC roof plank

Deflected RAAC roof plank

Primary Metsec beamsSecondary Metsec beams

Pre-existing roof support beams

The problemWhere RAAC planks have been used for flat roofing, problems can arise as the planks start to deflectover time. This deflection can allow rainwater to pond on the roof, which in turn, can exacerbate thestresses on the roof structure already caused by the deflection.

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Roof beams


20

Ceilings and service supports

Ceilings and service support systems

Service support/pipebridgeMetsec provide an economic system to formpipebridge and service supports.

Lightweight lattice joists are provided in pairsand braced together to form spans of up to 40m.

The majority of pipebridges are supplied with agalvanised finish for external applications.However, various paint specifications are alsoavailable where required.

Metsec parallel lattice beams are the idealsolution for the support of ceiling structureswithin existing buildings. Whether the ceiling is asimple suspension from a secondary grid of C-sections or is ‘walk-on’ and supported from thebottom chord of the lattice beam, Metsec has arange of solutions.

Lattice beams are ideal for clean rooms, datahalls, telecommunications facilities, retail unitsand secure locations where long, unobstructedspans are essential and where their light weightcan minimise the load on to the existingstructure.

Millennium Dome, LondonMillennium Dome, London

They can also allow the passage of servicesthrough the lattice’s web without any loss of headroom or need for exposed pipework which canform a potential dust trap.

Metsec lattice primary members together with Z or C-section secondary members provide a costeffective solution to ceiling/service supportrequirements.

Metsec parallel beamUsed with secondary C-sectionsto support a suspended ceiling.In the illustration shown, theability to run split-level ductingthrough the lattice without anyloss of internal headroom isclearly demonstrated. A furtherbenefit is that future changes tothe building services can easilybe accommodated by runningpiping or ducting through thelattice.


Metsec parallel beamsupporting walk-on ceilingMetsec parallel ceiling supportbeams can be used for walk-onceiling applications.

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Ceilings and service supports

Walk-on ceiling systems

Clean room ceiling support structure

Ceiling and service support structure

Metsec lattice beams are frequently used tocreate a support structure for walk-on ceilings inwhich an interlocking system of steel facedplanks is used to create a load bearing ceilingconstruction. These systems are particularlypopular in the creation of “clean rooms” wheresealing the joints of these planks creates a closedceiling void in which the high level mechanicaland electrical services can be installed withoutthe need for secondary floors or complex supportsystems.

These systems provide an excellent solution tothe location of services and are specificallydesigned to allow maintenance engineers to walkon top of the ceiling system. This facilitates theeasy access to services and components withoutthe need for the access equipment normallyassociated with more basic ceiling installations.

The two photographs to the left show projectswhere Metsec lattice beams are employed inwalk on ceiling constructions.


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Floor beams

Traditional floor systemsMetsec lattice joists offer a simple solution for theconstruction of both conventional and mezzaninefloors due to their excellent strength to weight ratio. This means that a typical lattice joist can weigh up to 50%less than their hot rolled counterparts.

Of great importance to the designer is the fact that theinternal space can be optimised by passing services throughthe web of the lattice joists rather than having to suspendthem underneath causing a significant loss of headroom.

Similarly, the ability to insert flush fitting timber sectionsinto the top and bottom chords offers a simple medium forthe fastening of floor decking and/or plasterboard ceilings.

White Rose Shopping Centre, Leeds.

Traditional floorsMetsec parallel floor joists at600mm centres with the floordecking nailed to the top chordand two layers of plasterboardto the bottom chord.

In addition to the direct reduction of the environmentalfootprint of a construction project by virtue of theirlighter weight, lattice beams can also help to reduce theenvironmental footprint of the project by using off-sitefabrication to speed up the construction process of thefloor as the lighter sections can generally be transportedand handled more efficiently on site.


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Floor beams

Mezzanine floorsMetsec parallel floor joists with C-sections supporting floor decking.

The photograph below shows aproject where 17m span lattice joistswere designed to carry storageloadings.

Zurich Insurance, Wiltshire

Mezzanine floor systems


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Fixing details

Typical fixing details

F1 – Shoe fixing to concrete padstone

F4 – Full depth seating with beam extended

F5 – Beam fixing to internal wall F6 – Beam laid to fall with full depth seat

F3 – Full depth fixing to concrete padstone

F2 – Beam laid to fallon sloping shoes


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Fixing details

F7 – Fixing to concrete face with loose angle cleats F8 – Shoe fixing to hot rolled steelwork

F9 – Shoe fixing to hot rolled steelwork (pair) F10 – Full depth fixing to the web of hot rolledsteelwork

F11 – Full depth fixing to hot rolled steelwork F12 – Fixing to internal hot rolled steelwork


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F13 – Beam to column flange fixing

Fixing details

Typical fixing details

F14 – Beam to column fixing with plate weldedto column

F15 – Beam to beam trimmer fixing F16 – Typical bridging fixing detail

F17 – Bracing fixing detail Note

‘F’ and ‘T’ details illustrate a typical range of connections that are

available. Other connections can be fabricated to suit site conditions .


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Fixing details

T1 – Full depth fixing with bearing plate T2 – Purlin to truss fixing

T3 – Truss to column flange fixing T4 – Standard shoe fixing to hot rolled steelwork

T5 – Beam to truss trimmer fixingT6 – Standard shoe fixing to concrete padstone


230

7070

6

100

90

x x

y

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Chord and bridging details

Chord details

35

50 2.5

3550

120

yx x

37.5 37.560

450

135

x xy

40 75 40155

575 x x

y

210

6565

5

80

100 x x

y

Nominal dimensions

Chord y Area rxx ryy Ixx Iyy Zxx Zyy

type mm cm2 cm cm cm4 cm4 cm3 cm3

MB 23.27 5.16 1.97 3.14 19.96 50.90 7.47 8.48

MD 24.25 8.53 1.93 3.66 31.84 114.12 12.36 16.91

MG 38.13 13.89 2.84 4.27 112.13 253.58 29.41 32.72

MJ 45.04 19.14 3.85 5.32 283.15 542.17 51.52 51.64

ML 45.51 23.84 3.85 5.94 353.90 840.11 64.94 73.05


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BridgingBridging is recommendedduring the construction periodto enable the beams to supportthe construction loads, and tohold the beams at the centresand positions indicated on theplans.

However, when constructionloads are deemed to be light,bridging can be omitted at thediscretion of the Metsec LatticeBeam Technical Department.

Bridging consists of steel anglesconnected to the top chord ofthe lattice. Bridging may alsobe required to the bottomchords depending on designconsiderations. The slendernessratio l/r of the bridging anglemust not exceed 250.

Chord and bridging details

Bridging details

Wind reversalWhere construction loads arelight the bottom chords shouldbe checked for compressiondue to the wind reversal forces.

Please contact Metsec LatticeBeam Technical Department forfurther advice.

Maximum spacing of bridging for chord sections (m)

Type MB MD MG MJ ML

3.8 4.4 5.2 6.4 7.5

Sizes of bridging angle for various joists centres

Centres of joists (m) Standard bridging angle (mm)

0 – 2.4 50 x 50 x 3

2.4 – 3.0 60 x 60 x 5

3.0 – 3.9 80 x 80 x 6

3.9 – 4.9 100 x 100 x 8

Bridging

Knee bracing


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Design examples and load tables

Design examples

Parallel beam - span/depth ratioAs a guide, depths of roof beam, conform approximatelyto the following:

Approximate depth = span/24i.e. 12m span/24 = 500mm deep

Design example

Joist span 10,000mm

Joist spacing 4,500mm

Roof loading:

Decking and insulation 0.20kN/m2

Ceiling and services 0.30kN/m2

Allow S.Wt steelwork 0.10kN/m2

Dead load 0.60kN/m2

Imposed load 0.60kN/m2

Unfactored total load 1.20kN/m2

Therefore load requirement = 1.2 x 4.5 (joist spacing) =

5.4 kN/m and imposed load requirements = 0.6 x 4.5 = 2.7kN/m.

Refer to load tables.

Use Metsec lattice beams ref: MD50

Total load capacity 5.52kN/m (>5.4)

Imposed load capacity 3.83kN/m (>2.7)

Important

The lighter the beam, the more cost effective the solution

DesignationThe designation of beam configurations and depths isgiven by a simple letter and number code, as follows:

Chord Depth at Configuration Pitch

type shallow end or radius

MB – ML (cm) T (tapered) Gradient (o)TR (pitched) Radius (m)

PP (parallel pitched)I (inverted)

CT (curved truss)CB (curved beam)

Example 1

MD 50

Thus MD50 comprises MD type chord sections with an overall beamdepth of 500mm without pitch or taper.

Example 2

MJ 60 TRW 100

Thus MJ60TRW(100) comprises MJ type chord sections with anoverall truss depth at the shallow end of 600mm rising to a centralridge with a Warren type web pattern and a 100 slope.

Stone Road, West Midlands


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Summerhill Primary School, West Midlands

Typical truss optionsN – type trussThis is the most economical type of joist or truss whenconsidering gravity loading only and where stressreversals are insignificant - i.e. longer diagonal membersare in tension.

Warren type trussMay be preferred in having a better appearance than theN – type joist or truss. Diagonals are alternatively strutsand ties.

This results in a frame less susceptible to deflection thanthe N – type.

Typical tapered truss options

Warren type truss with vertical postsAdditional members are introduced to the basic warrentype joist or truss to support loads which do not occur atnode positions.


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Lattice beam, in steel frameconstruction

Lattice beamThe Metsec lattice beam canprovide a very attractive,lightweight, economicalsolution when used as a mainsupport to the roof structure,being able to meet short,medium or long spanrequirements.

The beam can be provided withfully fixed end connectionsdetermined by simple frameanalysis if required.Alternatively, they can besimply supported to carryvertical applied dead andimposed loads and fixed forhorizontal wind as a commondesign assumption.

PurlinsThe most economic sectionused for supporting the roofcladding is a cold rolled purlin.

Metsec cold rolled Z-sectionpurlins provide adequatelateral restraint to the top(compression) chord of thelattice beams.

BracingThe longitudinal tensile forcesin the Metsec Z-section purlinsresulting from lateral restraintto the lattice beams aretransmitted to the diagonalrafter bracing system providedat each end of the building. Inaddition to providing stability tothe lattice beams, bracing alsoresists wind loading at thegable ends (i.e. gable postspropped at bracing nodepoints) and acts as stabilitybracing during erection.

For longer buildings additionalbracing may be required tointermediate bays.

Vertical bracing as shown onthe roof plan ensures that allforces are transmitted to thefoundations.

Optional bottom tie

Ridge

CL

Knee brace as required

Gable posts

Metsec lattice beam

Metsec lattice beam

Metsec lattice beam

Vert

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Vert

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Cleader rail

Met

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Raf

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Metsec Z-section purlins

Metsec lattice beam

Metsec lattice beam

Metsec lattice beam



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Lattice truss in load bearing wallconstruction

Lattice trussThe Metsec lattice truss provides alightweight, economic solutionwhen used as the roof lid mainsupport member on load bearingwall construction. The lattice formprovides a more flexible servicezone within the ceiling void.

Large spans of up to 40m areeasily accommodated.

PurlinsMetsec cold rolled Z-sectionpurlins are used as economicsupport to the roof cladding andprovide adequate lateral restraintto the top (compression) chord ofthe lattice truss.

Rafter bracingThe longitudinal forces in theMetsec Z-section purlins resultingfrom lateral restraint to the latticetruss are transmitted to thediagonal rafter bracing system.

Bottom tie bracingThe wind loading on verticalspanning side walls is resisted bya horizontal bracing systemutilising a steel or concrete ringbeam at bottom chord (eaves)level. This ring beam may bereturned on the gable ends toprovide intermediate lateralsupport to the walls.

The longitudinal ties also serve aslateral restraint members to thebottom chord of lattice truss incompression from wind uplift.

Optional bottom tie

Ridge

CL

Knee brace as required

Gable posts

Metsec lattice beam

Metsec lattice beam

Metsec lattice beam

Vert

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bra

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Vert

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Cleader rail

Raf

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Metsec lattice beam

Metsec lattice beam

Metsec lattice beam

Raf

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Hor

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pan

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beam

Metsec truss

Metsec truss

Metsec truss

Metsec truss

Eaves bracing

Long

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Long

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Ring beam

Load bearing walls

“Suspended” ceilingServices




Span (m)18 19 20 21 22 23 24 25 26 27 28 29 30

1.400.97

1.801.252.23 1.90 1.631.55 1.32 1.13

1.711.192.25 1.91 1.641.56 1.33 1.142.79 2.37 2.03 1.761.94 1.65 1.41 1.22

2.08 1.771.45 1.232.75 2.34 2.00 1.731.91 1.62 1.39 1.203.41 2.90 2.49 2.15 1.872.37 2.01 1.73 1.49 1.30

1.671.162.49 2.12 1.821.73 1.47 1.263.30 2.81 2.41 2.08 1.81 1.582.29 1.95 1.67 1.44 1.26 1.104.10 3.49 2.99 2.58 2.25 1.96 1.732.85 2.42 2.08 1.79 1.56 1.36 1.20

1.96 1.671.36 1.162.94 2.50 2.14 1.85 1.612.04 1.74 1.49 1.29 1.123.91 3.32 2.85 2.46 2.14 1.87 1.652.71 2.31 1.98 1.71 1.49 1.30 1.144.85 4.12 3.54 3.05 2.66 2.33 2.05 1.813.37 2.86 2.46 2.12 1.85 1.61 1.42 1.262.61 2.22 1.90 1.641.81 1.54 1.32 1.143.95 3.36 2.88 2.49 2.17 1.89 1.672.75 2.33 2.00 1.73 1.50 1.32 1.165.27 4.48 3.84 3.32 2.89 2.53 2.22 1.97 1.753.66 3.11 2.67 2.30 2.00 1.75 1.54 1.37 1.216.55 5.57 4.77 4.12 3.59 3.14 2.76 2.44 2.17 1.94 1.744.55 3.87 3.31 2.86 2.49 2.18 1.92 1.70 1.51 1.35 1.213.25 2.85 2.44 2.11 1.83 1.602.32 1.98 1.69 1.46 1.27 1.115.11 4.35 3.73 3.22 2.80 2.45 2.16 1.91 1.703.55 3.02 2.59 2.24 1.94 1.70 1.50 1.33 1.186.84 5.82 4.99 4.31 3.75 3.28 2.89 2.55 2.27 2.03 1.82 1.644.75 4.04 3.46 2.99 2.60 2.28 2.00 1.77 1.58 1.41 1.26 1.148.50 7.23 6.20 5.35 4.66 4.08 3.59 3.17 2.82 2.52 2.26 2.03 1.85.90 5.02 4.30 3.72 3.23 2.83 2.49 2.20 1.96 1.75 1.57 1.41 1.26.12 5.46 4.68 4.05 3.52 3.08 2.71 2.40 2.13 1.90 1.714.46 3.79 3.25 2.81 2.44 2.14 1.88 1.67 1.48 1.32 1.197.70 7.29 6.28 5.43 4.72 4.13 3.64 3.22 2.86 2.55 2.29 2.06 1.85.98 5.09 4.36 3.77 3.28 2.87 2.52 2.23 1.99 1.77 1.59 1.43 1.29.98 9.11 7.81 6.75 5.87 5.14 4.52 4.00 3.55 3.17 2.85 2.56 2.3

7.44 6.33 5.42 4.69 4.07 3.57 3.14 2.78 2.47 2.20 1.98 1.78 1.618 19 20 21 22 23 24 25 26 27 28 29 3037 41 45 50 55 60 65 71 77 83 89 96 10

34

Load tablesDesign examples and load tables

Joist Overall Typical node Ixx Self weight

type depth (mm) centres (mm) (cm4) (kg/m)MB22 220 250 816 10

MB27 270 350 1328 10

MB30 300 380 1697 11

MD30 300 380 2762 16

MB35 350 600 2416 12

MD35 350 600 3941 17

MG35 350 600 5429 28

MB40 400 600 3263 12

MD40 400 600 5334 17

MG40 400 600 7504 28

MB45 450 600 4240 13

MD45 450 600 6940 20

MG45 450 600 9926 29

MJ45 450 600 12965 37

MB50 500 600 5345 14

MD50 500 600 8759 19

MG50 500 600 12696 29

MJ50 500 600 16649 37

ML50 500 600 20650 46

MB55 550 600 6580 14

MD55 550 600 10791 19

MG55 550 600 15813 30

MJ55 550 600 20812 38

ML55 550 600 25824 47

MB60 600 600 7943 13

MD60 600 600 13037 18

MG60 600 600 19277 28

MJ60 600 900 25453 36

ML60 600 900 31594 45

MB65 650 600 9436 15

MD65 650 600 15496 20

MG65 650 600 23088 29

MJ65 650 900 30572 37

ML65 650 900 37960 46

MB70 700 900 11057 16

MD70 700 900 18168 21

MG70 700 900 27247 29

MJ70 700 900 36171 37

ML70 700 900 44922 46

MD80 800 900 24153 22

MG80 800 900 36606 30

MJ80 800 900 48803 38

ML80 800 900 60635 47

MD90 900 900 30990 22

MG90 900 900 47355 31

MJ90 900 900 63349 39

ML90 900 900 78732 48

MG100 1000 900 59492 32

MJ100 1000 900 79809 40

ML100 1000 900 99214 49

Span (m)Standard camber (mm)

Span (m)5 6 7 8 9 10 11 12 13 14 15 16 17

4.11 2.38 1.502.86 1.65 1.044.01 3.34 2.44 1.634.01 2.69 1.69 1.137.08 4.91 3.12 2.09 1.475.94 3.44 2.16 1.45 1.028.33 6.94 5.07 3.40 2.39 1.748.33 5.59 3.52 2.36 1.66 1.218.47 5.88 4.32 2.97 2.09 1.528.45 4.89 3.08 2.06 1.45 1.0610.68 8.90 7.24 4.85 3.40 2.48 1.8610.68 7.98 5.03 3.37 2.36 1.72 1.2923.13 15.83 9.97 6.68 4.69 3.42 2.57 1.98 1.5618.99 10.99 6.92 4.64 3.26 2.37 1.78 1.37 1.089.87 6.85 5.04 3.86 2.82 2.06 1.549.87 6.61 4.16 2.79 1.96 1.43 1.0710.73 8.95 7.67 6.56 4.61 3.36 2.52 1.9410.73 8.95 6.80 4.56 3.20 2.33 1.75 1.3525.17 19.29 13.78 9.23 6.48 4.73 3.55 2.73 2.15 1.7225.17 15.19 9.57 6.41 4.50 3.28 2.47 1.90 1.49 1.2011.27 7.82 5.75 4.40 3.48 2.67 2.0111.27 7.82 5.41 3.62 2.54 1.85 1.3913.85 11.54 9.89 7.76 6.00 4.37 3.28 2.53 1.99 1.5913.85 11.54 8.85 5.93 4.16 3.04 2.28 1.76 1.38 1.1126.76 22.27 16.36 12.21 8.57 6.25 4.70 3.62 2.85 2.28 1.85 1.5326.76 20.10 12.66 8.48 5.95 4.34 3.26 2.51 1.98 1.58 1.29 1.0626.36 21.97 18.83 15.95 11.20 8.16 6.13 4.73 3.72 2.98 2.42 1.99 1.6626.36 21.97 16.53 11.07 7.78 5.67 4.26 3.28 2.58 2.07 1.68 1.38 1.1512.66 8.79 6.46 4.95 3.91 3.17 2.53 1.95 1.5312.66 8.79 6.46 4.57 3.21 2.34 1.76 1.35 1.0613.41 11.17 9.58 8.38 6.90 5.52 4.14 3.19 2.51 2.01 1.6313.41 11.17 9.58 7.48 5.25 3.83 2.88 2.22 1.74 1.40 1.1328.01 23.34 18.55 14.20 10.97 8.00 6.01 4.63 3.64 2.91 2.37 1.95 1.6328.01 23.34 16.19 10.84 7.62 5.55 4.17 3.21 2.53 2.02 1.65 1.36 1.1327.70 23.08 19.78 17.31 14.38 10.48 7.88 6.07 4.77 3.82 3.11 2.56 2.1327.70 23.08 19.78 14.22 9.99 7.28 5.47 4.21 3.31 2.65 2.16 1.78 1.4834.96 29.14 24.97 21.85 17.84 13.00 9.77 7.53 5.92 4.74 3.85 3.17 2.6534.96 29.14 24.97 17.64 12.39 9.03 6.79 5.23 4.11 3.29 2.68 2.20 1.8412.74 9.76 7.17 5.49 4.34 3.51 2.90 2.40 1.89 1.5112.74 9.76 7.17 5.49 3.95 2.88 2.16 1.67 1.31 1.0512.76 10.64 9.12 7.98 7.09 6.21 5.11 3.93 3.09 2.48 2.01 1.6612.76 10.64 9.12 7.98 6.47 4.72 3.55 2.73 2.15 1.72 1.40 1.1529.00 24.16 20.71 15.88 12.55 9.96 7.48 5.76 4.53 3.63 2.95 2.43 2.0329.00 24.16 20.16 13.51 9.49 6.92 5.20 4.00 3.15 2.52 2.05 1.69 1.4128.75 23.95 20.53 17.97 15.97 13.11 9.85 7.58 5.97 4.78 3.88 3.20 2.6728.75 23.95 20.53 17.78 12.49 9.10 6.84 5.27 4.14 3.32 2.70 2.22 1.8536.29 30.25 25.92 22.68 20.16 16.26 12.22 9.41 7.40 5.93 4.82 3.97 3.3136.29 30.25 25.92 22.06 15.49 11.29 8.49 6.54 5.14 4.12 3.35 2.76 2.3011.97 9.97 7.88 6.04 4.77 3.86 3.19 2.68 2.28 1.8211.97 9.97 7.88 6.04 4.77 3.47 2.61 2.01 1.58 1.2712.00 10.00 8.57 7.50 6.67 6.00 5.45 4.74 3.74 2.99 2.43 2.00 1.6712.00 10.00 8.57 7.50 6.67 5.70 4.28 3.30 2.60 2.08 1.69 1.39 1.1629.78 24.82 21.27 17.55 13.87 11.23 9.12 7.03 5.53 4.42 3.60 2.96 2.4729.78 24.82 21.27 16.47 11.56 8.43 6.33 4.88 3.84 3.07 2.50 2.06 1.7225.73 21.44 18.38 16.08 14.30 12.87 11.70 9.28 7.30 5.84 4.75 3.91 3.2625.73 21.44 18.38 16.08 14.30 11.13 8.36 6.44 5.07 4.06 3.30 2.72 2.2732.48 27.07 23.20 20.30 18.05 16.24 14.77 11.51 9.06 7.25 5.90 4.86 4.0532.48 27.07 23.20 20.30 18.05 13.82 10.38 8.00 6.29 5.04 4.09 3.37 2.8116.85 11.70 8.60 6.58 5.20 4.21 3.48 2.93 2.49 2.15 1.7616.85 11.70 8.60 6.58 5.20 4.13 3.10 2.39 1.88 1.50 1.2222.55 18.79 15.19 11.63 9.19 7.45 6.15 5.17 4.41 3.56 2.89 2.38 1.9922.55 18.79 15.19 11.63 9.19 6.78 5.09 3.92 3.08 2.47 2.01 1.65 1.3830.41 25.34 21.72 19.01 15.19 12.31 10.17 8.41 6.62 5.30 4.31 3.55 2.9630.41 25.34 21.72 19.01 13.85 10.10 7.59 5.84 4.60 3.68 2.99 2.47 2.0626.49 22.07 18.92 16.55 14.71 13.24 12.04 11.04 8.76 7.02 5.70 4.70 3.9226.49 22.07 18.92 16.55 14.71 13.24 10.05 7.74 6.09 4.87 3.96 3.26 2.7233.52 27.94 23.94 20.95 18.62 16.76 15.24 13.83 10.88 8.71 7.08 5.84 4.8733.52 27.94 23.94 20.95 18.62 16.60 12.47 9.61 7.56 6.05 4.92 4.05 3.3818.25 12.67 9.31 7.13 5.63 4.56 3.77 3.17 2.70 2.33 2.03 1.7018.25 12.67 9.31 7.13 5.63 4.56 3.63 2.80 2.20 1.76 1.43 1.1820.73 17.28 14.81 12.60 9.96 8.06 6.66 5.60 4.77 4.11 3.39 2.79 2.3320.73 17.28 14.81 12.60 9.96 7.95 5.97 4.60 3.62 2.90 2.35 1.94 1.6227.15 22.62 19.39 16.97 15.08 13.38 11.06 9.29 7.81 6.25 5.08 4.19 3.4927.15 22.62 19.39 16.97 15.08 11.92 8.95 6.90 5.42 4.34 3.53 2.91 2.4327.03 22.52 19.31 16.89 15.02 13.51 12.29 11.26 10.37 8.30 6.75 5.56 4.6427.03 22.52 19.31 16.89 15.02 13.51 11.88 9.15 7.20 5.76 4.69 3.86 3.2234.30 28.59 24.50 21.44 19.06 17.15 15.59 14.29 12.88 10.31 8.38 6.91 5.7634.30 28.59 24.50 21.44 19.06 17.15 14.76 11.37 8.94 7.16 5.82 4.80 4.0021.62 18.02 15.44 13.51 11.48 9.30 7.69 6.46 5.50 4.75 4.13 3.63 3.1021.62 18.02 15.44 13.51 11.48 9.30 7.69 6.11 4.81 3.85 3.13 2.58 2.1527.72 23.10 19.80 17.32 15.40 13.86 12.60 10.78 9.19 7.92 6.83 5.63 4.6927.72 23.10 19.80 17.32 15.40 13.86 12.03 9.26 7.29 5.83 4.74 3.91 3.2627.67 23.06 19.76 17.29 15.37 13.83 12.58 11.53 10.64 9.88 9.11 7.50 6.2627.67 23.06 19.76 17.29 15.37 13.83 12.58 11.53 9.71 7.78 6.32 5.21 4.3435.33 29.44 25.24 22.08 19.63 17.67 16.06 14.72 13.59 12.62 11.31 9.32 7.7735.33 29.44 25.24 22.08 19.63 17.67 16.06 14.72 12.07 9.66 7.86 6.47 5.4022.28 18.57 15.91 13.93 12.38 10.54 8.71 7.32 6.24 5.38 4.68 4.12 3.6522.28 18.57 15.91 13.93 12.38 10.54 8.71 7.32 6.17 4.94 4.02 3.31 2.7627.85 23.21 19.90 17.41 15.47 13.93 12.66 11.61 10.46 9.02 7.85 6.90 6.0727.85 23.21 19.90 17.41 15.47 13.93 12.66 11.61 9.43 7.55 6.14 5.06 4.2227.86 23.21 19.90 17.41 15.48 13.93 12.66 11.61 10.71 9.95 9.29 8.71 8.1227.86 23.21 19.90 17.41 15.48 13.93 12.66 11.61 10.71 9.95 8.21 6.76 5.6435.83 29.86 25.59 22.39 19.90 17.91 16.28 14.93 13.78 12.80 11.94 11.20 10.0935.83 29.86 25.59 22.39 19.90 17.91 16.28 14.93 13.78 12.55 10.20 8.41 7.0127.68 23.07 19.77 17.30 15.38 13.84 12.58 11.53 10.65 9.89 8.81 7.74 6.8627.68 23.07 19.77 17.30 15.38 13.84 12.58 11.53 10.65 9.48 7.71 6.35 5.3027.72 23.10 19.80 17.32 15.40 13.86 12.60 11.55 10.66 9.90 9.24 8.66 8.1527.72 23.10 19.80 17.32 15.40 13.86 12.60 11.55 10.66 9.90 9.24 8.52 7.1035.94 29.95 25.67 22.46 19.97 17.97 16.34 14.97 13.82 12.83 11.98 11.23 10.57

35.94 29.95 25.67 22.46 19.97 17.97 16.34 14.97 13.82 12.83 11.98 10.59 8.835 6 7 8 9 10 11 12 13 14 15 16 173 4 6 7 9 12 14 16 19 22 26 29 33


Span (m)18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34

1.400.97

1.801.252.23 1.90 1.631.55 1.32 1.13

1.711.192.25 1.91 1.641.56 1.33 1.142.79 2.37 2.03 1.761.94 1.65 1.41 1.22

2.08 1.771.45 1.232.75 2.34 2.00 1.731.91 1.62 1.39 1.203.41 2.90 2.49 2.15 1.872.37 2.01 1.73 1.49 1.30

1.671.162.49 2.12 1.821.73 1.47 1.263.30 2.81 2.41 2.08 1.81 1.582.29 1.95 1.67 1.44 1.26 1.104.10 3.49 2.99 2.58 2.25 1.96 1.732.85 2.42 2.08 1.79 1.56 1.36 1.20

1.96 1.671.36 1.162.94 2.50 2.14 1.85 1.612.04 1.74 1.49 1.29 1.123.91 3.32 2.85 2.46 2.14 1.87 1.652.71 2.31 1.98 1.71 1.49 1.30 1.144.85 4.12 3.54 3.05 2.66 2.33 2.05 1.813.37 2.86 2.46 2.12 1.85 1.61 1.42 1.262.61 2.22 1.90 1.641.81 1.54 1.32 1.143.95 3.36 2.88 2.49 2.17 1.89 1.672.75 2.33 2.00 1.73 1.50 1.32 1.165.27 4.48 3.84 3.32 2.89 2.53 2.22 1.97 1.753.66 3.11 2.67 2.30 2.00 1.75 1.54 1.37 1.216.55 5.57 4.77 4.12 3.59 3.14 2.76 2.44 2.17 1.94 1.744.55 3.87 3.31 2.86 2.49 2.18 1.92 1.70 1.51 1.35 1.213.25 2.85 2.44 2.11 1.83 1.602.32 1.98 1.69 1.46 1.27 1.115.11 4.35 3.73 3.22 2.80 2.45 2.16 1.91 1.703.55 3.02 2.59 2.24 1.94 1.70 1.50 1.33 1.186.84 5.82 4.99 4.31 3.75 3.28 2.89 2.55 2.27 2.03 1.82 1.644.75 4.04 3.46 2.99 2.60 2.28 2.00 1.77 1.58 1.41 1.26 1.148.50 7.23 6.20 5.35 4.66 4.08 3.59 3.17 2.82 2.52 2.26 2.03 1.84 1.665.90 5.02 4.30 3.72 3.23 2.83 2.49 2.20 1.96 1.75 1.57 1.41 1.28 1.166.12 5.46 4.68 4.05 3.52 3.08 2.71 2.40 2.13 1.90 1.714.46 3.79 3.25 2.81 2.44 2.14 1.88 1.67 1.48 1.32 1.197.70 7.29 6.28 5.43 4.72 4.13 3.64 3.22 2.86 2.55 2.29 2.06 1.865.98 5.09 4.36 3.77 3.28 2.87 2.52 2.23 1.99 1.77 1.59 1.43 1.299.98 9.11 7.81 6.75 5.87 5.14 4.52 4.00 3.55 3.17 2.85 2.56 2.31 2.10 1.91 1.74 1.59

7.44 6.33 5.42 4.69 4.07 3.57 3.14 2.78 2.47 2.20 1.98 1.78 1.61 1.46 1.32 1.21 1.1018 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 3437 41 45 50 55 60 65 71 77 83 89 96 100 109 116 124 131

35


Notes on load tables1. All loads are safe working loads in kilo

Newtons per metre (kN/m).

2. Safe working loads have been derived byusing a global safety factor of 1.6 on ultimateloads calculated in accordance with BS 5950-1: 2000 and 5: 1998.

3. It is recommended that Unfactored total loaddeflections (before camber) are limited tospan/250. Therefore safe working loadsshown in black type are calculated with adeflection limit of span/250.

4. BS 5950-1: 2000 and 5: 1998 recommends thatUnfactored imposed load deflections arelimited to span/360 where applicable.Therefore safe working loads shown in redtype are calculated with a deflection limit ofspan/360.

5. By calculating Unfactored imposed loads andtotal loads in kilo Newtons per linear metre(kN/m) and referring to the appropriate tablea suitable selection can be made by satisfyingboth imposed load and total load criteria.

6. Tables are based on:

6.1 The top (compression) chord of the beamis provided with adequate lateral restraints atspacings not greater than 1.8m.

6.2 The load is uniformly distributed on thefull span.

7. Roof beams are fabricated with an upwardcamber. The approximate camber for variousspans is shown in the tables.

Floor joists are supplied straight unless acamber is specifically requested.

8. When design requirements are for depthsgreater than 2.0m, or when curved, pitched ortapered profiles are required, please refer toLatticeSPEC design software or consult theMetsec Lattice Beam Technical Department.

Span (m)6 7 8 9 10 11 12 13 14 15 16 17

2.38 1.506 1.65 1.04

3.34 2.44 1.632.69 1.69 1.13

8 4.91 3.12 2.09 1.474 3.44 2.16 1.45 1.023 6.94 5.07 3.40 2.39 1.743 5.59 3.52 2.36 1.66 1.217 5.88 4.32 2.97 2.09 1.525 4.89 3.08 2.06 1.45 1.068 8.90 7.24 4.85 3.40 2.48 1.868 7.98 5.03 3.37 2.36 1.72 1.293 15.83 9.97 6.68 4.69 3.42 2.57 1.98 1.569 10.99 6.92 4.64 3.26 2.37 1.78 1.37 1.087 6.85 5.04 3.86 2.82 2.06 1.547 6.61 4.16 2.79 1.96 1.43 1.073 8.95 7.67 6.56 4.61 3.36 2.52 1.943 8.95 6.80 4.56 3.20 2.33 1.75 1.357 19.29 13.78 9.23 6.48 4.73 3.55 2.73 2.15 1.727 15.19 9.57 6.41 4.50 3.28 2.47 1.90 1.49 1.207 7.82 5.75 4.40 3.48 2.67 2.017 7.82 5.41 3.62 2.54 1.85 1.395 11.54 9.89 7.76 6.00 4.37 3.28 2.53 1.99 1.595 11.54 8.85 5.93 4.16 3.04 2.28 1.76 1.38 1.116 22.27 16.36 12.21 8.57 6.25 4.70 3.62 2.85 2.28 1.85 1.536 20.10 12.66 8.48 5.95 4.34 3.26 2.51 1.98 1.58 1.29 1.066 21.97 18.83 15.95 11.20 8.16 6.13 4.73 3.72 2.98 2.42 1.99 1.666 21.97 16.53 11.07 7.78 5.67 4.26 3.28 2.58 2.07 1.68 1.38 1.156 8.79 6.46 4.95 3.91 3.17 2.53 1.95 1.536 8.79 6.46 4.57 3.21 2.34 1.76 1.35 1.061 11.17 9.58 8.38 6.90 5.52 4.14 3.19 2.51 2.01 1.631 11.17 9.58 7.48 5.25 3.83 2.88 2.22 1.74 1.40 1.131 23.34 18.55 14.20 10.97 8.00 6.01 4.63 3.64 2.91 2.37 1.95 1.631 23.34 16.19 10.84 7.62 5.55 4.17 3.21 2.53 2.02 1.65 1.36 1.130 23.08 19.78 17.31 14.38 10.48 7.88 6.07 4.77 3.82 3.11 2.56 2.130 23.08 19.78 14.22 9.99 7.28 5.47 4.21 3.31 2.65 2.16 1.78 1.486 29.14 24.97 21.85 17.84 13.00 9.77 7.53 5.92 4.74 3.85 3.17 2.656 29.14 24.97 17.64 12.39 9.03 6.79 5.23 4.11 3.29 2.68 2.20 1.844 9.76 7.17 5.49 4.34 3.51 2.90 2.40 1.89 1.514 9.76 7.17 5.49 3.95 2.88 2.16 1.67 1.31 1.056 10.64 9.12 7.98 7.09 6.21 5.11 3.93 3.09 2.48 2.01 1.666 10.64 9.12 7.98 6.47 4.72 3.55 2.73 2.15 1.72 1.40 1.150 24.16 20.71 15.88 12.55 9.96 7.48 5.76 4.53 3.63 2.95 2.43 2.030 24.16 20.16 13.51 9.49 6.92 5.20 4.00 3.15 2.52 2.05 1.69 1.415 23.95 20.53 17.97 15.97 13.11 9.85 7.58 5.97 4.78 3.88 3.20 2.675 23.95 20.53 17.78 12.49 9.10 6.84 5.27 4.14 3.32 2.70 2.22 1.859 30.25 25.92 22.68 20.16 16.26 12.22 9.41 7.40 5.93 4.82 3.97 3.319 30.25 25.92 22.06 15.49 11.29 8.49 6.54 5.14 4.12 3.35 2.76 2.307 9.97 7.88 6.04 4.77 3.86 3.19 2.68 2.28 1.827 9.97 7.88 6.04 4.77 3.47 2.61 2.01 1.58 1.270 10.00 8.57 7.50 6.67 6.00 5.45 4.74 3.74 2.99 2.43 2.00 1.670 10.00 8.57 7.50 6.67 5.70 4.28 3.30 2.60 2.08 1.69 1.39 1.168 24.82 21.27 17.55 13.87 11.23 9.12 7.03 5.53 4.42 3.60 2.96 2.478 24.82 21.27 16.47 11.56 8.43 6.33 4.88 3.84 3.07 2.50 2.06 1.723 21.44 18.38 16.08 14.30 12.87 11.70 9.28 7.30 5.84 4.75 3.91 3.263 21.44 18.38 16.08 14.30 11.13 8.36 6.44 5.07 4.06 3.30 2.72 2.278 27.07 23.20 20.30 18.05 16.24 14.77 11.51 9.06 7.25 5.90 4.86 4.058 27.07 23.20 20.30 18.05 13.82 10.38 8.00 6.29 5.04 4.09 3.37 2.815 11.70 8.60 6.58 5.20 4.21 3.48 2.93 2.49 2.15 1.765 11.70 8.60 6.58 5.20 4.13 3.10 2.39 1.88 1.50 1.225 18.79 15.19 11.63 9.19 7.45 6.15 5.17 4.41 3.56 2.89 2.38 1.995 18.79 15.19 11.63 9.19 6.78 5.09 3.92 3.08 2.47 2.01 1.65 1.381 25.34 21.72 19.01 15.19 12.31 10.17 8.41 6.62 5.30 4.31 3.55 2.961 25.34 21.72 19.01 13.85 10.10 7.59 5.84 4.60 3.68 2.99 2.47 2.069 22.07 18.92 16.55 14.71 13.24 12.04 11.04 8.76 7.02 5.70 4.70 3.929 22.07 18.92 16.55 14.71 13.24 10.05 7.74 6.09 4.87 3.96 3.26 2.722 27.94 23.94 20.95 18.62 16.76 15.24 13.83 10.88 8.71 7.08 5.84 4.872 27.94 23.94 20.95 18.62 16.60 12.47 9.61 7.56 6.05 4.92 4.05 3.385 12.67 9.31 7.13 5.63 4.56 3.77 3.17 2.70 2.33 2.03 1.705 12.67 9.31 7.13 5.63 4.56 3.63 2.80 2.20 1.76 1.43 1.183 17.28 14.81 12.60 9.96 8.06 6.66 5.60 4.77 4.11 3.39 2.79 2.333 17.28 14.81 12.60 9.96 7.95 5.97 4.60 3.62 2.90 2.35 1.94 1.625 22.62 19.39 16.97 15.08 13.38 11.06 9.29 7.81 6.25 5.08 4.19 3.495 22.62 19.39 16.97 15.08 11.92 8.95 6.90 5.42 4.34 3.53 2.91 2.433 22.52 19.31 16.89 15.02 13.51 12.29 11.26 10.37 8.30 6.75 5.56 4.643 22.52 19.31 16.89 15.02 13.51 11.88 9.15 7.20 5.76 4.69 3.86 3.220 28.59 24.50 21.44 19.06 17.15 15.59 14.29 12.88 10.31 8.38 6.91 5.760 28.59 24.50 21.44 19.06 17.15 14.76 11.37 8.94 7.16 5.82 4.80 4.002 18.02 15.44 13.51 11.48 9.30 7.69 6.46 5.50 4.75 4.13 3.63 3.102 18.02 15.44 13.51 11.48 9.30 7.69 6.11 4.81 3.85 3.13 2.58 2.152 23.10 19.80 17.32 15.40 13.86 12.60 10.78 9.19 7.92 6.83 5.63 4.692 23.10 19.80 17.32 15.40 13.86 12.03 9.26 7.29 5.83 4.74 3.91 3.267 23.06 19.76 17.29 15.37 13.83 12.58 11.53 10.64 9.88 9.11 7.50 6.267 23.06 19.76 17.29 15.37 13.83 12.58 11.53 9.71 7.78 6.32 5.21 4.343 29.44 25.24 22.08 19.63 17.67 16.06 14.72 13.59 12.62 11.31 9.32 7.773 29.44 25.24 22.08 19.63 17.67 16.06 14.72 12.07 9.66 7.86 6.47 5.408 18.57 15.91 13.93 12.38 10.54 8.71 7.32 6.24 5.38 4.68 4.12 3.658 18.57 15.91 13.93 12.38 10.54 8.71 7.32 6.17 4.94 4.02 3.31 2.765 23.21 19.90 17.41 15.47 13.93 12.66 11.61 10.46 9.02 7.85 6.90 6.075 23.21 19.90 17.41 15.47 13.93 12.66 11.61 9.43 7.55 6.14 5.06 4.226 23.21 19.90 17.41 15.48 13.93 12.66 11.61 10.71 9.95 9.29 8.71 8.126 23.21 19.90 17.41 15.48 13.93 12.66 11.61 10.71 9.95 8.21 6.76 5.643 29.86 25.59 22.39 19.90 17.91 16.28 14.93 13.78 12.80 11.94 11.20 10.093 29.86 25.59 22.39 19.90 17.91 16.28 14.93 13.78 12.55 10.20 8.41 7.018 23.07 19.77 17.30 15.38 13.84 12.58 11.53 10.65 9.89 8.81 7.74 6.868 23.07 19.77 17.30 15.38 13.84 12.58 11.53 10.65 9.48 7.71 6.35 5.302 23.10 19.80 17.32 15.40 13.86 12.60 11.55 10.66 9.90 9.24 8.66 8.152 23.10 19.80 17.32 15.40 13.86 12.60 11.55 10.66 9.90 9.24 8.52 7.104 29.95 25.67 22.46 19.97 17.97 16.34 14.97 13.82 12.83 11.98 11.23 10.57

4 29.95 25.67 22.46 19.97 17.97 16.34 14.97 13.82 12.83 11.98 10.59 8.836 7 8 9 10 11 12 13 14 15 16 174 6 7 9 12 14 16 19 22 26 29 33


36

Load tablesDesign examples and load tables

Factory extension, Oldbury

Joist Overall Typical node Ixx Self weight

type depth (mm) centres (mm) (cm4) (kg/m)MG110 1100 900 73019 32

MJ110 1100 900 98184 40

ML110 1100 900 122080 50

MG120 1200 1200 87935 31

MJ120 1200 1200 118472 39

ML120 1200 1200 147330 48

MJ130 1300 1200 140675 40

ML130 1300 1200 174965 49

MJ140 1400 1200 164792 40

ML140 1400 1200 204984 50

MJ150 1500 1200 190823 41

ML150 1500 1200 237388 51

MJ160 1600 1200 218769 42

ML160 1600 1200 272176 51

MJ170 1700 1200 248628 42

ML170 1700 1200 309348 52

MJ180 1800 1200 280402 43

ML180 1800 1200 348905 53

MJ190 1900 1200 314089 44

ML190 1900 1200 390846 54

MJ200 2000 1200 349691 44

ML200 2000 1200 435172 55

Span (m)Standard camber (mm)

10 12 14 16 18 20 22 24 26 28 30 32 3413.63 11.36 9.74 8.52 6.78 5.49 4.32 3.3313.63 11.36 9.74 7.80 5.48 3.99 3.00 2.3113.67 11.39 9.76 8.54 7.59 6.83 5.81 4.47 3.52 2.82 2.2913.67 11.39 9.76 8.54 7.36 5.37 4.03 3.11 2.44 1.96 1.5917.88 14.90 12.77 11.18 9.94 8.94 7.22 5.56 4.37 3.50 2.85 2.35 1.9617.88 14.90 12.77 11.18 9.15 6.67 5.01 3.86 3.04 2.43 1.98 1.63 1.3612.35 10.29 8.82 7.72 6.86 6.03 4.98 4.01 3.1512.35 10.29 8.82 7.72 6.59 4.81 3.61 2.78 2.1912.32 10.26 8.80 7.70 6.84 6.16 5.60 5.13 4.24 3.40 2.7612.32 10.26 8.80 7.70 6.84 6.16 4.87 3.75 2.95 2.36 1.9216.49 13.74 11.78 10.30 9.16 8.24 7.49 6.71 5.28 4.23 3.44 2.83 2.3616.49 13.74 11.78 10.30 9.16 8.05 6.05 4.66 3.67 2.94 2.39 1.97 1.6412.14 10.11 8.67 7.58 6.74 6.07 5.52 5.06 4.67 4.04 3.2812.14 10.11 8.67 7.58 6.74 6.07 5.52 4.45 3.50 2.80 2.2816.35 13.62 11.68 10.22 9.08 8.17 7.43 6.81 6.27 5.02 4.08 3.36 2.8016.35 13.62 11.68 10.22 9.08 8.17 7.19 5.54 4.35 3.49 2.83 2.34 1.9511.82 9.85 8.44 7.39 6.57 5.91 5.37 4.93 4.55 4.22 3.84 3.1711.82 9.85 8.44 7.39 6.57 5.91 5.37 4.93 4.10 3.28 2.67 2.2016.13 13.44 11.52 10.08 8.96 8.06 7.33 6.72 6.20 5.76 4.78 3.94 3.2816.13 13.44 11.52 10.08 8.96 8.06 7.33 6.48 5.10 4.08 3.32 2.74 2.2811.45 9.54 8.18 7.16 6.36 5.73 5.21 4.77 4.40 4.09 3.82 3.5811.45 9.54 8.18 7.16 6.36 5.73 5.21 4.77 4.40 3.80 3.09 2.5515.83 13.19 11.31 9.89 8.80 7.92 7.20 6.60 6.09 5.65 5.28 4.56 3.8015.83 13.19 11.31 9.89 8.80 7.92 7.20 6.60 5.91 4.73 3.85 3.17 2.6411.04 9.20 7.89 6.90 6.14 5.52 5.02 4.60 4.25 3.94 3.68 3.45 3.2511.04 9.20 7.89 6.90 6.14 5.52 5.02 4.60 4.25 3.94 3.54 2.92 2.4315.48 12.90 11.06 9.67 8.60 7.74 7.04 6.45 5.95 5.53 5.16 4.84 4.3615.48 12.90 11.06 9.67 8.60 7.74 7.04 6.45 5.95 5.42 4.41 3.63 3.0310.61 8.84 7.58 6.63 5.89 5.30 4.82 4.42 4.08 3.79 3.54 3.31 3.1210.61 8.84 7.58 6.63 5.89 5.30 4.82 4.42 4.08 3.79 3.54 3.31 2.7715.08 12.57 10.77 9.43 8.38 7.54 6.86 6.28 5.80 5.39 5.03 4.71 4.4415.08 12.57 10.77 9.43 8.38 7.54 6.86 6.28 5.80 5.39 5.01 4.13 3.4410.15 8.46 7.25 6.35 5.64 5.08 4.61 4.23 3.90 3.63 3.38 3.17 2.9910.15 8.46 7.25 6.35 5.64 5.08 4.61 4.23 3.90 3.63 3.38 3.17 2.9914.65 12.21 10.46 9.15 8.14 7.32 6.66 6.10 5.63 5.23 4.88 4.58 4.3114.65 12.21 10.46 9.15 8.14 7.32 6.66 6.10 5.63 5.23 4.88 4.58 3.889.69 8.08 6.92 6.06 5.38 4.85 4.41 4.04 3.73 3.46 3.23 3.03 2.859.69 8.08 6.92 6.06 5.38 4.85 4.41 4.04 3.73 3.46 3.23 3.03 2.8514.18 11.82 10.13 8.87 7.88 7.09 6.45 5.91 5.46 5.07 4.73 4.43 4.1714.18 11.82 10.13 8.87 7.88 7.09 6.45 5.91 5.46 5.07 4.73 4.43 4.179.23 7.69 6.59 5.77 5.13 4.62 4.20 3.85 3.55 3.30 3.08 2.89 2.729.23 7.69 6.59 5.77 5.13 4.62 4.20 3.85 3.55 3.30 3.08 2.89 2.7213.70 11.42 9.79 8.56 7.61 6.85 6.23 5.71 5.27 4.89 4.57 4.28 4.03

13.70 11.42 9.79 8.56 7.61 6.85 6.23 5.71 5.27 4.89 4.57 4.28 4.0310 12 14 16 18 20 22 24 26 28 30 32 3412 16 22 29 37 45 55 65 77 89 100 116 131


37


Showcase Cinema, Dudley

Notes on load tables1. All loads are safe working loads in kilo Newtons per

metre (kN/m).

2. Safe working loads have been derived by using aglobal safety factor of 1.6 on ultimate loads calculatedin accordance with BS 5950-1: 2000 and 5: 1998.

3. It is recommended that Unfactored total loaddeflections (before camber) are limited to span/250.Therefore safe working loads shown in black type arecalculated with a deflection limit of span/250.

4. BS 5950-1: 2000 and 5: 1998 recommends thatUnfactored imposed load deflections are limited tospan/360 where applicable. Therefore safe workingloads shown in red type are calculated with adeflection limit of span/360.

5. By calculating Unfactored imposed loads and totalloads in kilo Newtons per linear metre (kN/m) andreferring to the appropriate table a suitable selectioncan be made by satisfying both imposed load and totalload criteria.

6. Tables are based on:

6.1 The top (compression) chord of the beam isprovided with adequate lateral restraints at spacingsnot greater than 1.8m.

6.2 The load is uniformly distributed on the full span.

7. Roof beams are fabricated with an upward camber.The approximate camber for various spans is shownin the tables.

Floor joists are supplied straight unless a camber isspecifically requested.

8. When design requirements are for depths greaterthan 2.0m, or when curved, pitched or taperedprofiles are required, please refer to LatticeSPECdesign software or consult the Metsec Lattice BeamTechnical Department.


3838

Services and design software

Services and general notes

Detailing serviceWorking from Architects’ and ConsultingEngineers’ drawings, Metsec’s team of engineersand specialist 3D draughtsmen will producestructural layouts and sections to assist the siteteam along with full fabrication drawings.

NBS PlusTechnical specifications for Metseclattice beams are also available viaNBS Plus (www.nbsplus.com). Thisfacility enables you to create concise,

technically accurate up to date specificationswhich can be copied directly into your buildingspecifications thereby maintaining specificationquality and saving you time.

By using NBS Building you can be assured youare using the industry standard specificationsystem that conforms to best practice. It providesextensive guidance to help you select and editthe right clauses for your project

Customer serviceMetsec are committed to providing the highestlevels of customer satisfaction and ensure thatour staff are trained to the highest possible levelsin order to assist our customers at all stages of thedesign and installation process.

Our sales teams in particular have a thoroughknowledge of our products and should be able toresolve most of your questions quickly andprofessionally.

Research and developmentMetsec operate a policy of continuous researchand development reserving the rights to changethe specification for products in this literaturewithout prior notice.

Company RegistrationMetsec plc.Registered Office: Broadwell Road, Oldbury,West Midlands B69 4HF.Company Number: 1551970 (England)

CPDThe Metsec Lattice Beam Division offer acontinuous professional developmentpresentation which has been accredited by theConstruction CPD Certification Service in the useand application of Metsec products andLatticeSPEC design software. These can easilycan be arranged by contacting the Metsec LatticeBeam Division on 0121 601 6000 or by visitingwww.metsec.com.

Tividale High School, West Midlands.


3939

Services and design software

Software

Design software

Metsec are pioneers when it comes to theprovision of design software packages. Our firstpackage for lattice design was produced in 1989,since when we have been continually updatingand improving the packages that we offer.

Today, Metsec produce a number of stand-alonedesign software packages including LatticeSPECfor our complete range of lattice beam solutions.

This package enables the quick and easy designof all types of lattice beams. It also includes anoption to export the profile of the lattice with itsend section in .dxf format, enabling specifiers toimport direct to their working drawings and toquickly and efficiently complete their detailing.

For a free copy of the latest LatticeSPEC softwareplease contact Metsec on 0121 601 6000 or visitour website: www.metsec.com

Designed and produced by Communication Design Partnership 01959 562777

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Metsec plcBroadwell Road, Oldbury, West Midlands, B69 4HFTel: 44+ (0) 121 601 6000Fax: 44+ (0) 121 601 6109email: [email protected]

Lattice Beam DivisionLightweight Lattice Joists and TrussesTel: +44(0) 121 601 6000Fax: +44(0) 121 601 [email protected]

Purlin DivisionZ and C-Sections for Building Shell ApplicationsC-Sections for Mezzanine FloorsTel: +44(0) 121 601 6000Fax: +44(0) 121 601 [email protected]

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Metstrut DivisionCable Ladder and Metal Framing Systems for M&E SupportTel: +44(0) 121 601 6085Fax: +44(0) 121 601 [email protected]

Hepsec DivisionDry Linings, Partitioning and Ceiling SupportSystemsTel: +44(0) 2476 585600Fax: +44(0) 2476 [email protected]

Metsec plc is a member of the Profilform Divisionof the voestalpine group with companies inAustria, Belgium, Brazil, Czech Republic, France,Germany, Russia and the U.S.A.

© Copyright METSEC plc 2008

In the interests of a policy of continuous research and development,

Metsec Building Products Ltd reserve the right to change the

specifications in this publication without prior notice.

486.2 Lattice Beams 23:Layout 1 2/10/08 09:50 Page 2

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