Please brochure for more information.

April 2010
(Replaces November 2005)
ZINCALUME
®
COAT E D ST E E L P RO DU CT S
ZINCALUME® Coated Steel
New Zealand Steel Limited introduced ZINCALUME®, zinc/aluminium alloy coated steel to the
New Zealand market in 1994. ZINCALUME® coated steel represents a significant improvement on
the traditional zinc coated galvanised steel. Since its introduction, ZINCALUME® coated steel has
been widely accepted and has the major share of the steel building products market.
The ZINCALUME® coated steel has been formulated to give a significantly longer service life than a
galvanised coating in the majority of applications*. This is of particular value in New Zealand where
the prevailing winds carry corrosive salt laden air many kilometres inland.
The ZINCALUME® steel coating combines the corrosion protection of aluminium with the sacrificial
protection of zinc, giving the advantages of both metals. The resulting alloy coating enhances
corrosion resistance, making it ideal for such applications as roofing and cladding.
ZINCALUME® coated steel is produced by a continuous hot dip process similar to that used to
manufacture galvanised steel. While both ZINCALUME® steel and galvanised steel products have a
steel base, galvanised steel has a coating of 100% zinc, whereas ZINCALUME® coated steel has an
alloy coating of 43.5% zinc, 55% aluminium and 1.5% silicon. Zincalume® coated steel has met the
requirements of AS1397:2001, and is manufactured under a quality management system to monitor
ongoing compliance with this Standard.
Cross Section of ZINCALUME® Coated Steel
PA G E O N E
* Refer INFORMATION TO HELP YOU AVOID PROBLEMS (page 5) and SPECIAL ENVIRONMENTS (page 11) for more information.
ZINCALUME®coatedsteelisrecommendedforthemanufactureof:
• roofingandflashings
• wallcladding
• guttersanddownpipes
PA G E T W O
• fences
• garagedoors
• gardensheds
• somevehicleexhaustcomponents
• flues
andotherapplicationswherelonglifeisanessentialrequirement.Itisformable,weldableand
readilyacceptspaintfinishes.
ZINCALUME® COATED STEEL CONTINUES A TRADITION Of DEPENDAbILITy
Zinc/aluminiumcoatedsteelhasanimpressivetrackrecordwithover100milliontonnesproduced
worldwidetotheendof2008.
Thezinc/aluminiumalloycoatingwasoriginallydevelopedintheUSAbyBethlehemSteel.BHP
SteelinAustraliawasfirsttotakefulladvantageoftheZINCALUME®steelcoating’scharacteristics.
ItwasintroducedintoAustraliain1976andquicklygainedwideacceptanceamongusers.
Architects,engineersandbuilderssawthepracticalandaestheticmeritsofthenewproduct.
fLASHINg
fLASHIN
gS AND ACCESSORIES
Flashingsandridgecappingshouldbemanufacturedfromthesamecoatingsystemasusedforthe
mainroofareatoensureequaldurabilityforCOLORSTEEL®prepaintedsteelandZINCALUME®
coatedsteelproducts.Extendedridgecaps,softzinc,orpracticessuchascuttingandnotching
arerecommended.
Wherepenetrationflashingsarerequired,neopreneorsiliconerubber,EPDMaluminiumorsoftzinc
allgiveexcellentperformance.
MAR
ARk
kIN
INg
g ZINCALUME® CO
COA
ATED STEEL
BlackleadpencilsmustneverbeusedformarkingGALVSTEEL™,ZINCALUME®coatedsteelor
COLORSTEEL®prepaintedsteelproducts.Thecarboninthepencilpromotescorrosionwhichwill
etchthesurface,leavingapermanentmark.Useapencilofanyothercolour.
ZINCALUME® – bUILDIN
UILDINg
g fOR THE fUTURE
Thegalvanisingprocesswhichbroughtsheetsteelintowidepopularityasaroofingmaterialwas
firstpatentedbyaFrenchchemistin1837.Thesamebasicprinciplesarestillappliedtoproduce
today’shotdipgalvanisedandZINCALUME®steelcoatings.
Commercialproductionof‘galvanisediron’beganinBritainin1838.Forroofing,flatsheetsof
galvanisedironhadtobesupportedorunderlaidiftheyweretobestructurallysound.Theprinciple
ofcorrugationsolvedthisproblem.Whenthetwoideasofgalvanisingandcorrugatingwere
combined,anewerainbuildingtechnologywasborn.
InNewZealandthe‘corrugatediron’roofisasmuchapartofourEuropeanheritageasthegum
diggersofNorthlandandtheGoldminersofCentralOtago.
NewZealandSteelfirstcommissionedthegalvanisinglinein1968.Thiswasthefirsttimethat
continuouslycoatedgalvanisedcoilhadbeenlocallyproduced.In1994thesameline,followinga
considerableupgrade,startedproductionofanewproduct,ZINCALUME®coatedsteel,whichhas
provedtobeofexceptionalbenefittothebuildingindustry.
TheupgradedlineiscapableofproducingbothtraditionalgalvanisedsteelandZINCALUME®
coatedsteelusinga‘dualpotsystem’.Thelinemodificationsalsoincludedequipmenttoapplythe
mostrecentlydevelopedpassivationsystemforunpaintedZINCALUME®coatedsteelproduct.
PA G E T H R E E
HOW THE ZINCALUME® STEEL COATING ENHANCES STEEL
CORR
ORROSION
OSION RESIST
ESISTANCE
ANCE
PA G E F O U R
ZINCALUME®coatedsteelhassuperiorlongtermcorrosionresistanceinmostatmospheric
conditions.Thisisachievedthroughthecombinationofthesacrificialprotectionofthezincandthe
barrierprotectionofthealuminium.
Testsitesfromaroundtheworldoveraperiodoftwenty-fiveyearshaveprovidedawealthof
informationaboutcomparativeperformanceofgalvanisedandZINCALUME®coatedsteelproducts.
Testsitesareplacedinmanydifferentenvironments,rangingfromtypicalrural,toseveremarine.
CorrosionratesaredeterminedbyexposingsamplesofZINCALUME®coatedsteelandgalvanised
steelonstandardtestracksandregularlymonitoringthecoatingperformanceoveranumberofyears.
Thoughcorrosionratesvaryaccordingtotheseverityofconditions,ZINCALUME®steelcoatings
out-performgalvanisedcoatingsinalmostallenvironments.Thisisparticularlytrueinmarine
environmentswhereZINCALUME®coatedsteelwillprovideasignificantlylongerservicelifethan
galvanisedsteel.
Estimated life
of galvanised and
ZINCALUME®
coated steel
APPEARANCE
ZINCALUME®coatedsteelhasafinelyspangledsilverymattfinish.Afterexposurethesurface
finishdarkensovertimeastheresincoatingweathersaway.Thiscanoccuratvaryingrates
duetodifferencesinaspect,degreeofshadingandtheeffectofrainrivuletsoverthe
ZINCALUME®surface.Thischangeisanaturaloneandisvisualonly.Theprotectiveproperties
oftheproductarenotaffected.
PAINTIN
AINTINg
g ZINCALUME® CO
COA
ATED STEEL
ZINCALUME®coatedsteelisreadilypaintableusinggoodqualityprimersandwater-basedacrylic
topcoats.Paintmanufacturers’instructionsshouldbefollowed.
Dirt,greaseandanyloosematerialsmustbecleanedoffsothesurfaceiscleananddrypriortothe
firstcoatbeingapplied.
INfORMA
ORMATION
TION TO HELP yOU AvOID PRObLEMS
Inalmostallapplications,ZINCALUME®coatedsteelwillout-performgalvanisedsteel.Thereare
however,asmallnumberofapplicationsforwhichgalvanisedsteelismoresuitable.
ZINCALUME® coated steel must not be used for:
• Formworkincontactwithwetconcrete.
• P
roductstobeembeddedinconcrete.However,whereverysmallvolumesofconcreteare
involved(e.g.splashes)whichareabletocurequickly,thereislittlecorrosiveeffect.
• Animalshelterswhereammonialevelsareconstantlyhigh.
• Fertiliserstorageshedsandcontainers.
• Culverts,orwhereZINCALUME®coatedsteelmaterialisburiedintheground.
• Watertanks.
• Coolroomproducts.
Since1994ZINCALUME®hasbeenusedasthesubstrateforNewZealandSteel’s
architecturalrangeofprepaintedsteelproducts.
Becausetheentirecoatingoperationiscarriedoutunderstrictfactory-controlledconditions,
COLORSTEEL®prepaintedsteelcoatingsprovideafarsuperiorfinishtomostsiteappliedcoatings
intermsofstrength,durabilityandflexibility.
ThecoloursofferedintheCOLORSTEEL®prepaintedsteelproductrangearespeciallyselectedto
complementNewZealandarchitecturalstylesandourlandscape.
PA G E F I V E
• Highlyalkalineenvironments(e.g.cementmanufacture).
PA G E S I X
MAINTENANCE
Allroofingandcladdingproductsaresubjecttothecumulativeeffectsofweather,dustandother
deposits.Normalrainwashingwillremovemostaccumulatedatmosphericcontaminantsfrom
roofs.Forwallcladding,manualwashingevery3to12months,dependingonthepaintsystem,
isrecommendedinmoderatetoverysevereenvironmentstopreventaccumulationofdirt,debris
orothermaterialnotremovedbyrainwashing.Forareasthatdonotreceiveanyoradequaterain
washing(calledunwashedareas)suchassoffits,wallcladdingundereaves,undersideofgutters,
fascias,shelteredareasofgaragedoorsandunwashedroofareas,moreextensivemanualwashing
isrequired.Similarly,otherHigh Riskareas,aroundflues,undertelevisionaerialsoroverhanging
treesandsitespronetomould,lichen,birddroppingsordebris,needtohaveextensivemanualwashing.
Regularwashingofsteelproductsincreasesthedurabilitybyreducingattackfromairbornesalts
andpollutants.
Steelsurfacesshouldbemanuallywashedwithwaterandaspongeorasoftnylon-bristledbrush.
Forlargeareasitmaybemoreappropriatetousewaterblastingatpressuresupto20Mpa.
If New Zealand Steel Limited products are maintained according to the following
recommendations, the requirements of the New Zealand building Code b2 for 15 year
durability for roofs and exterior walls will be met or exceeded.
Note:
1. TheNewZealandBuildingCodedurabilityrequirementdoesnotincludeaestheticappearance.
2. TheNewZealandBuildingCoderequiresadurabilityof15yearsminimum(withmaintenance)
forroofing,includingvalleys,andwallcladdingproducts.Thismeansnomoisturepenetration duetoproductfailure.
3. T
heNewZealandBuildingCoderequiresadurabilityof5yearsminimum(withmaintenance)for
rainwaterproducts,guttersanddownpipes.Thismeansnoperforationduetoproductfailure.
4. NewZealandSteelLimitedproductsaredesignedtoexceedtheNewZealandBuildingCode
B2:Durabilityrequirements.Continuedmaintenanceandoverpaintingwillgreatlyextend
theultimatelifeofallproducts.
5. W
herea50yeardurabilityisrequiredORwhereaproductistobeusedinaggressiveinternal
environments,NewZealandSteelLimitedshouldbeconsulted.
6. InIndustrialEnvironments,thetypeofpollutiongeneratedmayaltertheabove
recommendations.Ifindoubt,consultNewZealandSteelLimited.
ThefollowingmaintenanceinformationintheEnvironmentalChartisforguidanceonly.
Eachproprietarybuildingproductshouldcarryitsownmanufacturers’recommendationsforusage.
NewZealandSteelLimitedwillnotacceptresponsibilityforproprietaryroofingandcladding
productswhichdonotconformtoourrecommendationsformanufacturing,environmentaluse
ormaintenance.
Unwashed
Unw
ashed areas
PA G E T W E LV E
Compared to galvanised steel, ZINCALUME® coated steel performs exceptionally well in most
areas not regularly washed by rainwater. However, as with any steel based product, regular
washing of areas not naturally rain washed is essential to ensure that a satisfactory life is realised
from the product.
ZINCALUME® steel
cladding with large
soffits resulting in
unwashed areas.
R
ZINCALUME® steel
cladding.
WATER PONDIN
PONDINg
g
Roofs
Wheretheroofpitchislow,changesinroofloadingsmayresultinanegativepitchandconsequently
leadtowaterponding.WaterpondingisdetrimentaltotheperformanceofZINCALUME®coated
steelproducts.Thefollowingconditionscommonlycausewaterponding:
• Over-spacedpurlins.
• Deformationoftimberpurlins.
• Placementofexternalloadssuchasairconditioningunits.
• R
igidfixingonlongspanswhichcausesdeformationoftheprofileasaresultof
thermalexpansion.
Design Guide:
1. Neveruseapitchoflessthan3degreesortherecommendedfortheprofile,whicheveris
thegreater.Pitchesoflessthanthisinvalidatethewarranty.
2. Designtheroofaccordingtotheprofilemanufacturer’sspecifications.
3. Onminimumpitchroofs,ensurethatthegutterendofprofiledsheetsisturneddown.
4. Allowforthermalexpansiontopreventprofiledistortion.
5. C
onsidertheuseofwalkwaystopreventdamagewheretheroofmaybesubjecttoheavy
foottraffic.
6. Ensureroofpenetrationsdonotblocktheflowofwaterfromtheroof.
gutter
utters
s
Guttersmustbeinstalledwithadequatefalltoensureallwateristransportedtoappropriately
locateddownpipes.Pondingoccurswhenwaterremainsinthegutterwhenthefallisinadequate.
Overtime,thiscausesdegradationtothecoatingandultimatelyleadstogutterperforation.
Perforationofthegutterasaconsequenceofinadequatefallorpondinginvalidatesboththe
manufacturerandproducerwarranties.Theinstallationanddownpipeconstructionshouldallowthe
guttertodraincompletely.
Regularguttercleaningandmaintenanceisrequiredtoremoveleavesandotherdebristhatmay
restrictwaterflowtodownpipes.Particularcareshouldbetakenattheentrancetodownpipesand
corners,toavoidblockagesleadingtowaterponding.
Agutterprotectionsystem(oranyotherproduct)thatentrapswaterbetweenitselfandany
steelproductsurfaces,restrictingthecoatedsteel’sabilitytodry,isnotrecommendedandisan
exclusionintheproductwarranty.
WORKING WITH ZINCALUME® STEEL
ZINCALUME®coatedsteelandgalvanisedproductshaveverysimilarworkingcharacteristics.
However,thereareafewcharacteristicsthatyoushouldbeawareof.
Atthecutedge,ZINCALUME®steelprovidessimilarprotectiontogalvanisedcoatings.
Thezinc/aluminiumalloycoatingofZINCALUME®coatedsteelprovidesgalvanicprotectiontobare
steelexposedatcutedgesandbydeepscratches.
PASSI
ASSIv
vATION
SurfacepassivationenhancestheprotectionofthegalvanisedandZINCALUME®steelproduct
duringstorage,forming,handlingandfixing.Itlargelyeliminatestheneedforrollformingoils,offers
improvedwetstackcorrosionresistanceandgenerallymakestheproductmoremarkresistant
duringhandlingandfixing.
PA G E T H I R T E E N
PROTECTION AT CUT EDgES
HANDLIN
ANDLINg
g AND STORA
ORAg
gE
PA G E F O U R T E E N
Thenormalstoragecare,sitecleanlinessandinstallationproceduresusedforGALVSTEEL™
productsapplytoZINCALUME®coatedsteelproducts.
Althoughpassivationprovidesimprovedprotectionduringstorage,careshouldstillbetaken.
IfZINCALUME®coatedsteelbecomeswetduringstorage,theproductshouldbeimmediately
separated,wipedwithacleanclothandplacedinapositionwhereitcancompletelyairdry.
fORMINg
fORMIN
g
AswithGALVSTEEL™,ZINCALUME®coatedsteelissuitableforallbutthemostsevereforming
operations.
WithZINCALUME®coatedsteel,thepassivationsystemactsasadrylubricantandinmostcases
willeliminatetheneedforadditionallubricationinmostformingoperations.Solvent-basedlubricants
mustnotbeused.
WELDIN
ELDINg
g
ZINCALUME®steelcanbesatisfactorilyweldedusingthefollowingtechniques:
• GMA(GasMetal-Arc,oftencalledMIG)
• Resistancewelding(spotorseam)
• MMA(ManualMetal-Arc)
WhenweldingZINCALUME®steel,excessiveweldcurrentsmustbeavoided.Withcorrectwelding
procedures,sufficientcoatingisnormallyleftontheZINCALUME®coatedsteelsheettoprotectthe
substratefromcorrosion.Weldrepairshouldbecarriedoutbycoatingwithazinc-richpaint.
AdequateventilationmustbeprovidedeventhoughtheweldingofZINCALUME®coatedsteelgives
offfewerfumesthangalvanisedsteel.
JOININ
OININg
g AND SEALIN
EALINg
g
ZINCALUME®coatedsteelcannotbesoldered.JoinZINCALUME®coatedsteelinthesamewayas
recommendedforCOLORSTEEL®prepaintedsteelproducts.Useaneutralcuresiliconesealantin
conjunctionwithmechanicalfastenerssuchasblindrivets.Careshouldbeexercisedinthechoice
ofrivets.Aluminiumrivetsarerecommended.Monel,stainlesssteelandcarbonsteelrivetsmust
notbeused.
fASTENERS
MostfastenerscomplyingwiththecorrosionrequirementsofAustralianStandardAS3566
“Screws–Self-drillingforthebuildingandconstructionindustry”,aresuitableforusewith
ZINCALUME®steel.
• S
tainlesssteelfastenersshouldnotbeusedwithZINCALUME®coatedsteelor
COLORSTEEL®prepaintedsteelproductsinanyenvironment.
• Leadheadednailsmustnotbeused.
• Useonlylowcarbon(<15%)non–conductivesealingwashers.
COMMERCIAL WARRANTIES
CommercialwarrantiesareissuedthroughtheRollformerbyNewZealandSteelLimitedandthetermsare
specifictoeachcontract.
Inordertoensuretheappropriateproductisspecifiedfortheintendedservicelifeinanygivenenvironment,
NewZealandSteelLimitediskeentobeconsultedasearlyaspossibleinthedesignstagetoensure
correctmaterialselectionandbackingbyanappropriatewarranty.
Warrantyapplicationsaregenerallymadethroughtheroofingmanufacturerandwarrantyperiodsand
conditionsareassessedbyNewZealandSteelLimited.
Factorssuchasroofdesign,roofpitch,profile,coatingtype,internalandexternalenvironmentsandspecial
conditions(suchasrequirementfor“CleaninPlace”)areallassessedatthetimeofthewarrantyapplication.
Maintenancerequirementswillbespecifiedaspartofthewarranty.
DraftwarrantiesareavailablefromNewZealandSteelLimitedtosupporttendersforspecificprojects.The
termsandconditionsofthedraftwillremainunchangedprovidingthatthetermsoftheprojectareunaltered.
Awarrantyisissuedonthesatisfactorycompletionofthecontract.Installationmustbecarriedoutin
accordancewithNewZealandSteelLimited’srequirementsandaccordingtogoodtradepracticesas
detailedinthe“NZMetalRoofandWallCladdingCodeofPractice”,availablefromtheNZMetalRoofing
ManufacturersInc.
AsiteinspectionbyNewZealandSteelLimitedmaybecarriedoutpriortotheissuingofanywarranty.
Themaintenanceprogrammespecifiedinthewarrantymustbecompliedwithtovalidatethewarranty.
PA G E F I F T E E N
Z I N C A L U M E® C O A T E D
S T E E L
P R O D U C T S
F
MAXX™ is a trademark of New Zealand Steel Limited.
ENDURA™ is a trademark of New Zealand Steel Limited.
COLORSTEEL® is a registered trademark
of New Zealand Steel Limited.
ZINCALUME is a registered trademark
of BlueScope Steel Limited.
®
®
GALVSTEEL™ is a trademark of
New Zealand Steel Limited.
is a registered trademark of New Zealand Steel Limited.
NOTE: WithNewZealandSteelLimited’scommitmenttocontinuousimprovement,informationprovidedin
thispublicationmaybesubjecttomodification.Atthetimeofpublicationwebelievetheinformationcontained
inthisdocumentisthebestavailable.Nonetheless,wereservetherighttomodifyanyproduct,technique,
equipmentorstatementtoreflectimprovementsinthemanufactureandapplicationofcoilcoatedproducts.
TheinformationissuppliedwithoutprejudicetoNewZealandSteelLimited’sstandardtermsandconditions
of sale. In the event of any conflict betweenthisinformationandthestandardtermsandconditions,the
standardtermsandconditionsshallprevail.
ThiseditionoftheNewZealandSteelZINCALUME®Guidesupersedesallpreviouseditions.
Copyright©2010NewZealandSteelLimited.
NewZealandSteelLimited,PrivateBag92121,Auckland1142,NewZealand. Ph0-9-3758999 Fax0-9-3758213
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