plastic sheeting: its use for emergency shelter and other purposes

8/7/2019 Plastic Sheeting: Its use for emergency shelter and other purposes

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Plastic SheetingIts use for emergency she lterand other purposes

AN OXFAM TECHNICAL GUIDE

Prepared byJim Howard and Ron Spice


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First published March 1973Revised September 1977Second revision February 1981Third revision May 1989

Oxfam 1989

British Library Cataloguing in Publication DataHoward, Jim 1926-

Plastic sheeting: its use for emergency housingand other purposes - 2nd ed.1. Developing Countries. Residences. Buildingma terials. Plastic sheeting.I. Title II. Spice, Ron691 ' .92ISBN 0-85598-140-7

Oxfam is a partnership ofpeople committed to therelief of poverty, distressand suffering in any part ofthe world.We believe in the essentialdignity of people and Intheir capacity to overcomethe problems they facewhether they stem fromnatural, social, political oreconomic conditions. 85/MJ/89This book converted to digital file in 2010


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C o n t e n t s 1 Introduction 12 Types of flexible plastic sheeting available 33 Properties of polythene sheeting 53.1 General properties 53.2 Mechanical properties 63.3 Thicknesses 63.4 Colours 73.5 Sunshine degradation or weakening 83.6 Thermal properties of film-coveredstructures 93.7 Condensation in film-covered structures U4 Structures covered with plastic films 134.1 General points 134.2 Semi-cylindrical structure 1 44.3 Ridge tent structure 164.4 The Oxfam temporary shelter 225 Use of plastic sheeting in combination

with traditional construction materials 276 Details of manufacturers 297 Appendices 33I Useful data for water storageII Precipitation dataIII Other useful dataIV A guide to prices of polythene sheetingand accessories

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Introduct ion This technical guide arises from Oxfam'sexperience of using considerable quantities ofplastic shee ting in disaster situations . It hasbeen prepared to help field staff and othersunderstand the properties of these sheetingmaterials with a view to successful emergencyshelter construction.Plastic sheetings are now widely used in a varietyof structures, w ith a sa tisfactory degree ofreliability. This is demonstrated by the largeareas of greenhouses covered with plastic film tobe seen in the UK and elsewhere, and the greatnumber of semi-permanent plastic-clad farmbuildings used for farm stock, mushroom growingand storage.Polythene or, more correctly, polyethylenesheeting is now readily available in many parts ofthe world in large quantities and various gradesand qualities. In addition to its use for shelter, itcan be used for storage, tank linings, tarpaulin-type covers, groundsheets, food containers, cropprotection, inflated-walled houses, irrigation andsoil mulching.

EnvironmentalProtection We would like to emphasise the importance ofprotecting the environment from careless orindifferent management of plastic sheetingmaterials. Although these materials can be usedwith great effect for the purposes intended, theycan also be a major form of trash and litter inurban or rural situa tions . Some plastic materialsare biodegradable, however most will deterioratewith age and exposure to sunlight anddisintegrate. It is essen tial that every effortshould be made to control the distribution ofplastic sheetings, and that cuttings and otherplastic waste and garbage, should be gatheredup and utilised or disposed of in an appropriatemanner in the given conditions.


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Types offlexibleplasticsheetingavailable

Most plastic materials such as polythene,polyvinyl chloride (PVC), nylon, terylene,polypropylene, etc. can be produced in the formof thin, flexible sheeting. Also available areseveral kinds of flexible sheeting reinforced witha square mesh of natural or synthetic fibres togive greater strength and resistance to tearing.Such reinforcement increases the cost andweight per unit area. The maximum seam lesswidths of 100 0 gauge (25 0 micron or 0.25 mm)sheeting available are 4 metres reinforced and 8metres with no reinforcing. Wider sheets have tobe fabricated by stitch ing or heat sea ling. Thereinforced sheeting is available with ready-fixedeyelets in various spacings and configurations.Most of this guide relates to polythene sheeting.However, all the techniques discussed will workequally well with any flexible plastic sheeting tha tis available on site.


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P r o p e r t i e s 3 .1 General prope rtiesO f. . . Polythene sheeting has many advantages whenp o i y i n e n e c o m p a r e c | to other flexible materials that can beS h e e t i n g used as waterproof membranes. The chief

advantages are its low cost and weight per unitarea. It is available from the manufacturers instandard seamless sheeting up to 8 metres widein 1000 gauge or 1500 gauge (250 and 375microns). Its properties are as follows:a. Resistance to water. It is completelywaterproof and has a very low moisturevapour permeability.b. Chemical resistance. It is una ffected bysalts, dung- urine and most agriculturalchemicals. Petrol and lubricating oils maycause swelling by absorption and should notbe stored in contact with the sheeting.c. Ageing and weathering. Polythene sheetingcannot mildew or rot in store and it isunaffected by moisture . Clear shee tingdeteriorates slowly in sunshine and theprogressive loss of strength and flexibility maybecome apparent after a period of from 12 to15 months. Black sheeting , however, isresistant to sunlight and is recommended formost outdoor uses where light transm ission isnot essen tial.d. Thermal properties. The sheeting isflexible down to temperatures well belowfreezing point. It melts at 115" C (239* F), i.e.above the boiling point of water, but starts tosoften and lose tens ile strength at above80* C (175 F)


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3.2 Mechanical propertiesAs a buried membrane, the main propertiesrequired of any plastic material can be listed asfollows:

a. Flexibility, for ease of insta llation and toconform to minor undulations of the excavatedbase.b. Toughness, to remain undamaged duringthe installation process and subsequent'backfilling' operation.c. Durability, to retain its physical propertieswhen buried.d. Resistance to attack by soil fauna.e. Resistance to extremes of temperature.

Polythene is an inert material; it will not rot evenif buried in fertile soil and is not readily attackedby rodents or insects (although termites havebeen known to eat it and obviously polythene willnot provide a barrier to determined rats or mice).Polythene film will not de teriorate during storagealthough clear films must be stored in shade.

3.3 ThicknessesPolythene films are made in thicknesses rangingfrom 12 microns (50 gauge) to 1000 microns(400 0 gauge). Cost per unit area is proportiona lto thickness.Polythene sheeting is available from UK,Continental and American manufacturers inseamless widths of up to 8 metres in 1000gauge and in seamless widths of 17 metres in500 gauge. For ease of transport this wide


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sheeting is normally folded twice at the fac toryso that it can be rolled on to a cardboard core.Thus, 8 metre wide seam less sheeting is rolledon a 2 metre wide core. The weight of 10 00gauge sheeting is approximately 0.25 kg persquare metre.Polythene films are marginally stronger in themachine direction (along the length of the film)than in the transverse direction .Unreinforced polythene film of 1000 gauge istough enough to withstand wind stressesadequately if correctly fixed to structures . (Mostof the greenhouse acreage already mentioned iscovered with film of 500 gauge. The 50 kg sacksused to transport fertilisers and other chemicalsare usually made from 8 00 gauge sheeting andsome farmers use cut open plastic sacks forsimple farm buldings such as calf housing.)Polythene is the cheapest flexible plasticmaterial; for example, rolls of sheeting 8 metresx 28 metres would cost the UK farmer about 55in 1000 gauge or 105 in 1500 gauge, at 1988prices.For emergency housing purposes films thinnerthan 500 gauge would be unsuitable and it isrecommended that 10 00 or 15 00 gauge shouldbe used.

3.4 ColoursThe two most common colours are natural (clearor translucent) and black-pigmented. However, awide range of colours are available including red,blue, green and white.


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3 .5 Sunshine degradation or we aken ingClear plastic deteriorates fairly quickly in strongsunlight, although coloured polythenes are farless susceptible to degradation due to sunshine,with darker colours being more resistant andblack extremely resistant.All transparent plastic films are slowly weakenedby continuous exposure to sunshine. Thedurability of clear films intended for use outsidecan be considerably increased by addingchemicals called 'ultra-violet light absorbers'during manufac ture. Such 'ultra-violet lightinhibited' films currently commercially availablelast for at least two years when continuouslyexposed to sunsh ine on greenhouse structuresin the UK and it would be reasonable to expect atleast a one-year life from them even in countrieslike India. Ultra-violet light inhib ited films oftenhave a slight yellow or green colour which is dueto the nature of the absorbing chemical used.An interesting and important observation fromOxfam's field operations is that in locations withlong sunshine periods, at high temperatures thedegradation of reinforced plastic sheeting can beaccelerated when such sheetings are directlyexposed to sunlight. The reinforcing mater ial,whether this be metal wire, nylon or some plasticsubstance, can cause 'hot spots' within thesheeting and these temperature differentialscause local damage - brittleness or laminating -which reduces the structural strength of thesheeting material.To a lesser degree this same 'hot spot' problemarises where polythene film is stressed over anystructure which will absorb and hold heat, suchas metal tub ing. Film in contac t with this hotstructure will weaken more quickly for any givenamount of ultra-violet light radiation than film at

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air tempera ture. Ways of providing thenecessary protection are:a. Using a black polythene adhesive tape onthe outside of the polythene cover, so that itprotects the sheet itself from sunshine in thiscritical area (black polythene film is almostcompletely resistant to ultra-violet lightdegradation).b. Painting the film with aluminium orbitumastic paint at those points where it is incontact with the structure.c. Using anti-hot spot foam tape.

3 .6 Therm al prope rties of film-coveredstructuresBlack films expand when the sun shines andcontract at night. The actual expansion factor is1% per 38 C (100 F) tem perature change.Thus, a black plastic skin fitted to a structurewhen the sun is shining will become drum-tightafter nightfall; allowance should be made duringconstruction for this expansion and contraction.Clear films do not absorb heat energy from thesun and stay at ambient temperature;consequently the expans ion/contraction rate cangenerally be ignored.The thermal insulation properties ('U' factor) ofpolythene film s are poor. However, well-insulatedbuildings can be made by using two sheets ofplastic between which is sandwiched aninsulating material. In the UK some verysatisfactory mushroom-growing houses havebeen made in this way, using fibreglass ormineral wool as an insulant. In Italy, farmbuildings have been made in the same manner,using two layers of plastic with straw as an


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insulant. Any lightweight, dry material whichcontains a lot of air spaces would be suitable. Ifan organic material like straw or hay is so used itwould be desirable to pre-treat it with aninsecticide.If the tem perature within any plastic-cladstructure becomes too high in sunshine it can bereduced by spraying the outer surface withalum inium or light-coloured paint. Even a lime-wash or thin mud slurry might give temporaryprotection in extreme circumstances. Somepaints do not adhere very well to polythenesurfaces, and may need to be replaced after aperiod of tim e.Alternatively, a special polythene netting can beused over the sheeting to provide partial shade.Netting can also be used on its own to providesome protection against wind and sun insituations where some air movement andsubdued light is desirable.Living cond itions in an emergency sheltercovered with white, green or blue film might bemore agreeable than in structures clad with clearor black f i lm; day temperatures would ce rtainlybe more equable as emergency housing sheltersclad with plastic film will tend to be hot when thesun shines and cold at night.The fire hazards to the occupants of a structurecovered with a single skin of polythene areminimal; the film melts at temperatures inexcess of 100 C (212 F).However, this is not true where two layers ofplastic are used with a straw or hay inner filling .Clearly, the risk of ignition from cooking, lightingor cigarettes is much higher. It is essential thatthe fire risks and danger are appreciated by theusers of the structures.

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3 .7 Condens ation In film-covered struc turesWhen the temperature inside the shelter isgreater than tha t ou tside, condensation mayform on the inner surface . This may be causedby dampness in the soil and in this case theamount of condensation forming can be reducedby using a polythene film 'carpet' on the floor ofthe shelter to help prevent evaporation from thesoil. Condensation can also be caused bycooking or by the drying of wet clothes inside astructure. Increased ventilation can help toreduce condensation caused in these ways.

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Structures 4.1 General pointsc o v e r e d A , . 4 . . . .w i t h y plastic structure intended for emergencyW | W 1 housing must:plastic

f i l m a. offer shelter from the weather;b. be stable in wind;c. not be unbearably hot in daytime .Choice between different films as a coveringwill depend on :a. availability;b. expected life of the shelter;c. prevailing climatic conditions .

The circumstances in which any emergency andlocally available structural materials are used willobviously vary greatly. It would therefore beunhelpful to be dogmatic in these notes, whichare intended fo r general guidance only.There are three problems in supported polythenestructures, namely:

a. erection of the framew ork;b. securing the plastic to the framework;c. securing the plastic to the ground.

An obvious but extremely important rule withpolythene structures is to prevent the polythenepressing against sharp or rough points whichcould initiate tearing. Thus, contact areasbetween sheeting and other materials should befree of sharp edges and points and be as largeas possible to minimize stresses.

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4.2 Semi-cylindrical structureA semi-cylindrical structure covered with plasticfilm is commonly used for greenhouses in theUK. The basic structure is shown in Figure 1 .Because the plastic is stretched tautly over acurved surface no stress points exist and noflapping should occur in the wind. Thedimensions of the framework have to be tailoredto suit the plastic film available and to themethod used for securing the film to the ground.

Figure 1. Framework for plastic g reenhouseTubular spacers

Tubular support

Bracing al endsof tunnel only

Supportsfixed intoground

One possibility is that rolls of 8m width blackpolythene without eyelets or reinforcing might beavailable (see Table 1). In this case it might bemost appropriate to secure the sheeting byburying its edges in the ground . Methods of14


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doing this are described later, but about 800m mshould be allowed for this purpose on each side(Figure 2). The rema ining width will be sufficien tto cover a semi-circle of 4.3m diameter (D) and2.15m height (H). The length of curved polerequired for each arch, allowing for 30 0m in theground on both sides, is 7.35m.

Figure 2. Cross section of plastic greenhouse

Trench backfilledto retain sheet

Polythene sheeting

Edges of plasticsheet secured intrench at eitherside oi tunnel

Supports in ground

Another possibility is that rolls of 4m width greenreinforced tarpaulins and tentpegs are available.In this case two 4m rolls could be joined at thehighest point of the structure using the built-ineyelets. Securing the sheeting to the groundwith tent pegs through the other eyelets will allowthe full 8m width to be used for cover.In the UK, suitably curved steel tubing is used forthe framew ork. If th is is not available quickly in adisaster area, PVC rigid tube can be u tilized.PVC rigid tube arches sm oothly, returns to itsoriginal straightness, is relatively cheap,lightweight and easy to transport . The ridge of astructure made of PVC tubing could be joined to

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the hoops using standard Tee-piece pipe fittings(Figure 3) . The plastic sheeting is attached onlyto the end hoops. The end hoops should bebraced with guy ropes.

Figure 3. Use of 'Tee ' pieces to make greenhouse ridges fromPVC pipesPairs of oppos itelyfacing 'Tees'

4.3 Ridge tent structureThe ridge tent type of structure can probably bemade faster and with less special materials thanother types of emergency shelter. Basic she lterscan be made by driving two posts firmly into theground, stringing a rope tautly across them andhanging a sheet of plastic between the pos ts,burying its edges in shallow trenches the width ofthe tent apart (Figure 4).

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Figure 4. Basic shelter using rope as a ridge

Rope

Stake PolythenesheetingEdge of sheetburied and coveredwith stones

A more durable ridge tent can be constructed byspanning the upright posts with a m etal orwooden ridge pole. If the m aterials available tomake ridge poles are not sufficiently strong tospan the entire length of the ten t, thenintermediate uprights can be used (Figure 5).The stability of this type of structure will dependupon the rigidity of the ridge and the anchoring ofFigure 5. Simple plastic covered shelter with intermed iate uprights

BuriedUprightsupport pole

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the sheeting at soil level. Figures 6, 7 and 8illustrate techniques for securing the ridge usinground pole timber, tube steel and angle iron asthe ridge pole

Figure 6. Detail of apex of ridge using bush pole as the ridge

Polythene film

Figure 7. Fixing film to tubular metal ridgeTimber batten not lessthan 25mm

Timber batten

Polythene film

Figure 8. Fixing film to angle iron ridge'Roofing batten1 not lessthan 20mm x 25mm x section' Nail

Polythene film

Timber member is bolted,wired or tied ontoangle iron

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The ridge poles should be as free of protrusionsor irregularities as possible to avoid tearing theplastic and are most simply fixed to the uprightsby means of nails. Rather than having these nailspierce the plastic directly, it is preferable tosandwich the film between the ridge pole and asho rt upper piece of sawn timber which willresist tearing better. If sufficien t sawn timber isavailable, a piece the full length of the ridge polecould be used and nailed at several points.Obviously, sharp edges or rubbing points onthese lengths of sawn timber should be avoided.The simplest method of anchoring the sheetingto the ground is to dig a shallow trench and burythe length of sheeting. However, in areas withstrong winds or with sandy soils which do noteasily grip polythene, this is unlikely to proveadequate. Figures 9, 10 and 11 show methodsof improving the anchorage between thepolythene and the soil. The techniquesillustrated in Figures 9 and 10 have thedisadvantage of burying quite long lengths ofsheeting, with the result of reducing the effectivecoverage of the tent.

Figure 9. Using stones to secure plastic at ground level

Trench backfilled

Soil level

Stone

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Figure 10. Using timber to secure plastic at ground levelPolythenefilmTrench backfilled.

Figure 11. Securing plastic at ground level using sawn timber

Batten or similar25mm x 20mmtimber

Polythene

Edge of polytheneis wrapped around battenand nailed to timberfixed at soil level

Timber rail fixed atground level50mm x 50mm75mm x 50mm

Soil level J/ /

Alternatively, where available, tent pegs can beused; however, they will require specialreinforcing eyelets to prevent the sheet tearing.Some plastic sheetings are manufactured witheyelets built in at various centres (see Table 1).When sheeting materials need to be fitted witheyelets in the field, these can be suppliedseparately. They come in two pieces and arefixed through sheeting m aterials e ither by using amandrel and die, or, for the snap-and-fix 'ARRO'eyelets, simply by hammering.

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Sheet materials should be double thickness, ifpossible, at eyeletting points. The materialshould be folded back from the edge, say100mm, before inserting the eyelet.If no other fixing methods are available, sheetingcan be secured by tying a knot in the corner of asheet (like tying a knot in a handkerchief) and, ifnecessary, tying a rope around the knot asshown in Figure 12.

Figure 12. Use of knot for securing p lasticCorner of polythene sheet

Rope t ied round knot ^ To anchor point

Where high winds are anticipated, the locationand orientation of the shelters should takeaccount of likely wind direction. In addition someof the following measures should be taken :a. The use of guy ropes, good practice in allcircumstances, is essential in areas withstrong winds.b. Any available ne tting material placed overthe plastic sheeting will help to reduce winddamage.c. Where available, reinforced polythenesheeting shoufd be used for the m ain body ofthe tent as its far greater resistance to tearingmakes the additional expenditure worthwhile.

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d. Special polythene mesh can be used as awind break, normally as a free standing barrierin front o f a line of ten ts. (Thin polythene meshmaterial is commonly used in Europe to protectcrops or prevent snow drifting on exposedhillsides.)Where very cold conditions are experiencedpeople using emergency she lters sometimesexcavate part of the floor area within the tent toprovide a sleeping space free from draughts.

4.4 The Oxfam temporary shelterThe Oxfam Technical Unit have designed a simpleridge tent, in kit form, based on polythenesheeting and tubular steel, to allow a rapidresponse to the need for durable temporaryshelters in emergency situations (Figure 13).

Figure 13. The Oxfam Temporary Shelter

The advantages of the kit are its ease ofhandling and transportation, simple erection,durability and low cost ( 60 in 1988 in the UK).22


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The tent's framework consists of a 4m steelridge pole supported at its ends and mid-point by2m high steel tent poles and secured by guyropes. One sheet of reinforced plastic goes overthe ridge pole and is pierced by the tent polesthrough reinforced eyelets. A second squaresheet of reinforced plastic is cut diagonally andeach half used to make doorways to close theends of the tent. The items making up this kitare listed in Table 2.

Table 2 Kit list of Oxfam temporary shelterITEM

i0

0

o14

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QUANTITY

7 metre x 4 metre 1reinforcedblack plasticsheeting

4 metre x 4 metre 1reinforcedgreen plasticsheeting

2 metre long x 25m m 3diameter metaltent poles1.9 me tre ridge poles 2male and female4 0 metre guy rope 1Wooden guy 6adjustment block45 0m m guy rope pegs (18") 6250m m tent pegs (10") 1 0

Card of 10 eyelet 1reinforcementsAccess ories bag 1

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The tent is large in size, with a floor area of 16square m etres, and can in an emergency sleep16 adu lts, although it is more suited to a familyunit of 6 to 1 0 persons plus belongings. The unitweight of the kit is 25kg.

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The Oxfam Temporary Shelter

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Use ofplasticsheetingincombin-ation withtraditionalmaterials

Plastic sheeting can be used in combination withtraditional construction materials to great effect.Plastic sheeting will considerably improve theresistance to wind and rain of traditionalconstruction methods while traditional materialssuch as grasses and ea rth can help overcomethe poor insulation properties associated withpolythene structures. In this way semi-permanent, as opposed to temporary, shelterscan be construc ted. A fine example is inSouthern Sudan, where traditional racubas(hemispherical structures made from a timberframework covered with reed or grass m atting orany other suitable material available) have beenconsiderably improved by the use of plasticsheeting sandwiched between the inner timberframework and an outer layer of empty sacks andcardboard . The use of sheeting was of particularimportance in this instance as the grass andreeds, traditionally used, were in short supply.In Bangladesh and India plastic sheeting hasbeen used in conjunction w ith bamboo m atting ina very successful way. Several thousand houseshave been built using plastic sheeting as awaterproof and windproof membrane sandwichedbetween an inner and outer woven bamboo mat(Figure 14).

Figure 14. Plastic and bamboo matting house, Bangladesh

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Details ofManufact-urersSuppliers of polythene sheetingMonarflex LtdLyon WayHatfield RoadSt AlbansHerts AL4 OLQAnaplast LtdLundholm RoadArdeerStevenstonAyrshire KA20 3NQCalnay LtdMaerdy Industrial EstateRhymneyGwent NP2 5XQBritish Visqueen LtdYarm RoadStockton-on-TeesCleveland TS18 3RDZedcor Marketing LtdBridge Street MillBridge S treetWitneyOxon 0X8 6U

Suppliers of reinforced polythene tarpaulinsMonarflex LtdLyon WayHatfield RoadSt AlbansHerts AL4 OLQ

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Suppliers of polythene lay-flat tubing andpolythene bagsZedcor Marketing LtdBridge Street MillBridge StreetWitneyOxon 0X8 6U

Suppliers of polypropylene ropeMonarflex LtdLyon WayHatfield RoadSt AlbansHerts AL4 OLQ

Makers and suppliers of eyelets and woodentent rope runnersThe North Face (Scotland) LtdPO Box 1 6Industrial EstatePort GlasgowScotland PA14 5XL

Makers and suppliers of tent poles and pegsAllvic Engineering CoElm CrescentKingston-upon-ThamesSurrey KT2 6HL

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Makers and suppliers of adhesive tapes forpolythene sheetingDRG Sellotape ProductsElstree WayBorehamwoodHerts W D6 1RUGawler PlasticsUnit 2Northavon Business CentreDean RoadYateBristol BS17 5NH

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Appendices Appendix I Useful data for water storage1 gallon of water1 cubic foot of water1 cubic metre1 gallon1 litre of water1 cubic metre of water1 cubic yard of water1 cubic yard1 cubic metre1 square metre1 hectare

= 10 Ib= 6.25 gallons= 1000 litres = 220 gallons= 4,546 litres= 1 kilogram= 1000 kilograms= 764.6 kilograms= 0.7646 cubic metres= 1.308 cubic yards= 1.196 square yards= 2.47 acres

Appendix II Precipitation data1 mm of water1 inch of water1 inch of water1 acre - inch1 acre - foot1 mm of water1 acre -10 0 mm1 hectare -100 mm1 hectare - inch

= 10,00 0 litre of water/hectare= 22,610 gallons/acre= 41/2 gallons/square yard= 22,610 gallons= 271,320 gallons= 1 litre of water/square metre= 405 cubic metres = 89,00 0

gallons= 1,000 cubic metres = 220,000

gallons= 254 cubic metres = 55,880

gallons

Appendix III Other useful data1,000 microns1 metre

1,000 gauge1 US gallon1 kilogram

= 1 millimetre = 0.039inches= 1,000 m illimetres = 3.28 feet= 0.25 millimetres = 0.0 1 inches= 0.83 Imperial gallons = 3.76

litres= 2.2 pound Avoirdupois

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Appendix IV A guide to prices of polythenesheeting and accessories (1988)Black non-reinforced 10 00 gauge 0 .2 3 /s q . metreBlack non-reinforced 15 00 gauge 0 .4 6 /s q . metreBlack reinforced 100 0 gauge 0 .7 6 /s q . metreGreen reinforced 10 00 gauge with bu ilt-in eye lets

0 .95 / sq . metre'ARRO' snap-and-fix eyelets 82 .0 0 per 10 00Oxfam temporary shelter 6 0. 00 per kitAirfreight - as a rough costing use 1.50 per kilogramfor transporting quantities of plastic sheeting.

This book has been prepared byThe Technical UnitOxfam House274 Banbury RoadOxford 0X2 7DZTel: (0865) 56777Fax: (08 65 ) 57 61 2Telex: 83 61 0

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plastic sheeting: its use for emergency shelter and other purposes

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