Alumasc Vtherm: Vacuum Insulated System for Inverted Roofs

www.alumascroofing.co.uk

NEW WAVE INSULATION SOLUTIONS FOR PROTECTED MEMBRANE FLAT ROOFS AND GREEN ROOFS

• Rigid vacuum insulation panel with optimal performance – aged design value thermal conductivity 0.007 W/m.K

• Insulationperformanceuptofivetimesbetterthan commonly used insulation materials

• Ideal for projects with shallow construction depth

• Protectsthewaterproofingmembrane

• Minimalwaterabsorption

• Resistant to freeze / thaw cycling

• Ideal for green roof applications

• Panelsareover90%recyclable(byweight)

• Resistant to the passage of water vapour

• Idealfornewbuildandrefurbishmentprojects

• Non-deleterious material

Microporous Core

Protective Wrap

Multi-Layer Foil

1. Alumasc Separation Layer

2. Alumasc XPS Insulation

3. Kingspan Optim-R Vacuum Insulation Panel

4. Protective Rubbercrumb Layer

5. Hydrogard Protection Layers Reinforced,modifiedbitumenprotectionsheets

6. HydrotechMM6125Waterproofing Highperformancebituminousstructuralwaterproofing

7. FlexFlashReinforcementLayers OptionsforFlexFlashForFlexFlashUN

6. HydrotechMM6125Waterproofing Highperformancebituminousstructuralwaterproofing

8. Alumasc Bitumen Primer

9. Structural Concrete

TYPICAL SYSTEM BUILD UP OPTION

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INTRODUCTION

The Problem

Whetheryouaredealingwithanewbuild,orupgradingtheroofsofexistingbuildings,theremaybearequirementtoachievelowU-valueswiththethinnestpossibleroofbuild-up.

Withnewbuildapplications,regulatoryrequirementsareevermorestringent,whileeconomicfactorsandtheneedtoconserveenergymeansthatenergyefficiencyisthehighestpriority.Oneofthemoreeffectiveapproachesistoimprovethermalperformancewhilekeepingtheoverallconstructionasthinaspracticable.Highperformanceinsulationproductsareavailablethatfulfilsome,butnotall,oftheregulatoryandperformancerequirements,particularlyinapplicationswherethereiscallforathinnerinsulationproduct.

Inrefurbishmentprojects,therecanbeanevengreaterneedtokeeproofbuild-upsasthinaspossible.Internalspacemaybeatapremium,ortheremaybelittleornospaceavailableforinstallingnewroofinsulation-forexampleinbuildingswherethereareplanningheightrestrictions.

TYPICAL CONSTRUCTIONS AND U-VALUES

Assumptions

U-valuesarecalculatedunderamanagementsystemcertifiedtotheBBASchemeforAssessingtheCompetencyofPersonstoUndertakeU-valueandCondensationRiskCalculations,usingthemethoddetailed in BS / I.S. EN ISO 6946: 2007 (Building Components and buildingelements.Thermalresistanceandthermaltransmittance.Calculationmethod),andusingtheconventionssetoutinBR443(ConventionsforU-valuecalculations).ThemethoddetailedinpartD4.2ofBS/I.S.ENISO6946:2007hasbeenusedtotakeaccountoftheeffectofahighperformancenon-woven,polyethylenemembraneovertheinsulation,andan(fx)factorof≤0.012hasbeenassumed.

Theyassumeanominalselectionofpostcodes,selectedtorepresenttheinfluenceofgeographicalvariationsinrainfallonthermalperformance.

Theceiling,whereapplicable,istakentobea3mmskimcoated12.5mmplasterboardwithacavitybetweenitandtheundersideofthedeck.

Please Note:

• For the purposes of these calculations the standard of workmanship has been assumed good, and therefore the correction factor for air gaps has been ignored.

• Thefiguresquotedareforguidanceonly.AdetailedU-value calculationandacondensationriskanalysisshouldbecompleted for each project.

• Ifyourconstructionisdifferentfromthosespecified,and/orto gainacomprehensiveU-valuecalculationalongwitha condensationriskanalysisofyourproject,pleaseconsultthe AlumascTechnicalDepartmentforassistance(seerearcover).

• For the purposes of these calculations, the bridging effect of the infillpanelhasbeentakentobe15%.

The Solution

TheAlumascVThermVacuumInsulatedSystemhasbeendevelopedtohelpsolvesuchproblems.AlumascVThermisaninvertedroofsystemincorporatingtheinnovativeKingspanOPTIM-Rinsulationpanelsystem.Thiscomprisesrigidvacuuminsulationpanelswithamicroporouscore,whichisevacuated,encasedandsealedinathin,gas-tightenvelope.Theresultisoutstandingthermalconductivityinthethinnestpossibleinsulationsolution.ThevacuuminsulationpanelsintheVThermSystemareaugmentedbyrigidextrudedpolystyreneinsulationinfillpanels,whichcanbecuttofitaroundproblemareassuchasrooflightsorventilatorkerbs.

Inretrofitapplications,theAlumascVThermVacuumInsulatedSystemistheidealsolutionforareaswherelackofspacecouldpreventupgradingoftheinsulation,andinnewconstruction,AlumascVThermcanenhanceU-valuesinareaswherethermalperformancewouldotherwisebediminished.

TheKingspanOPTIM-Rpanelshaveanagedthermalconductivityof0.007W/m-K,andhaveaninsulatingperformanceuptofivetimesbetterthancommonlyusedinsulationmaterials.

Aboveall,theAlumascVThermVacuumInsulatedSystemsolvestheproblemofinsulatingareaswherethereisalackofconstructiondepth.

DESIGN SERVICE

Bespoke Project Design

Alumascoffersafulldesignservice,whichmaximisestheratioofVacuumInsulationPanelstoinfillpanels.Wewilldesignthepanellayoutquicklyandeffectively,readyforclientapproval.

Eachproject-specificlayoutwillshowthesize,numberandlocationoftheVacuumInsulationPanelsandsimilardataforanyinfillpanelsthatmayberequired.

Formoredetailspleasecontactourtechnicalteamon 01744 648 400.

Kingspan OPTIM-R produced at Kingspan Insulation’s Pembridge manufacturingfacilityiscertifiedtoBES6001(FrameworkStandardfortheResponsibleSourcingofConstructionProducts)‘VeryGood’.

Linear Thermal Bridging

Makeprovisiontolimittheeffectsofcoldbridging.Ensurethatrooflightorventilatorkerbs,gutters,etc.areadequatelyinsulatedwithAlumascUpstandBoard.Similarlyinsulatearoundtheperimeteroftheroofontheinternalfaceofparapets.

Maintainaminimumdistanceof300mmbetweenthetopoftheinsulationupstandandthebottomofthehorizontalroofinsulation.Carrywallinsulationupparapetsashighastheflatroofinsulationupstand.PleasecontacttheAlumascTechnicalDepartmentforfurtheradvice(seebackcover).

Sample Specification Clause

SpecifytheVacuumInsulationPanelelementoftheVThermsystemsasfollows:

TheroofinsulationshallbetheAlumascVThermVacuumInsulationPanel……mmthick:comprisingarigidvacuuminsulationpanelwithamicroporouscore,whichisevacuated,encasedandsealedinathin,gas-tightenvelope.TheproductshallbemanufacturedunderamanagementsystemcertifiedtoISO9001:2008,ISO14001:2008, BS OHSAS 18001: 2007, and ISO 50001: 2011 and installed inaccordancewiththeinstructionsissuedbyAlumascRoofingSystems.

Protected Membrane Roofs

ThisliteraturedemonstratestheAlumascVThermVacuumInsulatedSystemusedasacomponentofprotectedmembraneroofingsystemswithagravelorpayingslabfinish,andasacomponentofgreen roofs.

Inprotectedmembraneroofingsystemstheinsulationislocatedabovethewaterproofing,aconstructionthatoffersseveraladvantagesovertraditionalwarmflatroofs.

• Becausethewaterproofingsystemisnotexposedtothe elements,itcanbeexpectedtohavealongerlifethannon- protectedmembranesystems.TheVThermSystemisprotected frommechanicaldamage,UVdegradation,anddailyandseasonal temperatureextremes.

• No condensation risk.

• TheroofachievesanEXT.FAAfireratingwithgravelballastand pavingslabprotectivefinishes.

• Insulationcanbeliftedtoallowinspectionofthewaterproofing.

• Additionalinsulationcanbeaddedatalaterdateifrequired.

• Successfulinstallationoftheinsulationisnotaffectedbyweather conditions.

Design Loads & Roof Structure

Thesuitabilityofanystructuretoacceptdesignloads–includingtheincreaseddeadloadfromballast,snowandrooftraffic–shouldbeverifiedinaccordancewithBS6399-3:1988(Loadingforbuildings.CodeofPracticeforimposedroofloads).

Theadditionalloadfromballastcanbeconsiderable.

Ballast Layer Dead Load

50 mm thick paving slabs 125 kg/m2

Gravel (16–32 mm diameter) 16 kg/m2 per 10 mm depth

Intensive green roof 180 – 500 kg/m2

Semi–intensive green roof 120 – 200 kg/m2

Extensive green roof 60 – 150 kg/m2

Thelayerofballastresistsupliftfromwind,preventsflotationoftheboardsafterheavyrain,preventsUVdegradationoftheboards,andgivestherooftherequiredexternalfireperformancerating.

DESIGN CONSIDERATIONS

Wind Loads

Ensurethattheresistancetowindupliftofthewaterproofingsystem,insulationandballastisassessedinaccordancewithBS6399-2:1997(Loadingsforbuildings.CodeofPracticeforwindloads)orBS/ I.S. EN 1991-1-4: 2005 (National Annex to Eurocode 1 Actions on structures.GeneralActions.WindActions).BREDigest295givesspecificdesignguidelinesforloose-laidinsulationsystems.

Inshelteredexposurezones,oronbuildingsofupto10storeys,theself-weightofaminimum50mmgravelballastlayer(minimum80kg/m2),installedoveranon-wovenpolyethylenemembrane,isgenerallysufficienttoensurethatboththeinsulationboardsandwaterproofingsystemremainstableunderthefulldesignload.

Inmoderateexposurezones,oronbuildingsofupto10to15storeys,a50mmgravelballastspecificationisgenerallysufficient,withtheperimeteradditionallyloadedwith50mmthickpavingslabs.

Seekspecialistadviceforsevereexposurezonesortallbuildingsover 15 storeys. Refer to BRE Digest 311 (Wind scour of gravel ballast onroofs).

FlotationTheballastspecificationsdetailedinthe‘WindLoads’section(above)willbesufficienttopreventflotationoftheinsulationboardsafterheavyrain.

Falls

ProtectedmembraneroofingsystemsincorporatingtheAlumascVThermVacuumInsulatedSystemcanbelaidonroofstozerofalls,allinaccordancewithHydrotechBBAcertificate90/2431.

RAINFALL FACTORS

Rainfall Analysis

TherequirementsofBS/I.S.ENISO6946:2007partD.4.2(Correctionduetowaterflowingbeneaththeinsulationandthewaterproofingmembrane)dictatethatinvertedroofconstructionsaresubjecttoageographicalrainfallanalysis.Thecoolingeffectofrainwaterflowingbetweenandbeneaththeinsulationboards,canmeanthatgreaterthicknessesofinsulationarerequiredtomeetdesiredU-values(particularlyinlocationsthatreceivehighlevelsofrainfall).

Theuseofahighperformancenon-wovenpolyethylenemembraneovertheinsulationcandramaticallyminimiseheatlossbyreducingtheamountofrainwaterthatflowsbetweentheinsulationboards.Thisreductioninrainwaterflowisrepresentedbytheinfiltration(fx)factorofthemembrane.Thefxfactorofamembraneisfall(gradient)specific,andanfxfactormeasuredonafallcannotbeusedtorepresenttheperformanceofamembraneifinstalledhorizontally.

Drainage

Whenassessingthenumberandtypesofrainwateroutlet,refertoandensurecompliancewithBSEN12056-3:2000(Gravitydrainagesystemsinsidebuildings.Roofdrainage,layoutandcalculation).Therainwateroutletsshouldallowrainwatertobedrainedfromtheroofsurfaceatboththemembranelevelandtheuppersurfacelevel.

Types of Green Roof

Therearethreeprincipaltypesofgreenroof.

Extensive green roofs - Havearelativeshallowgrowingmedium,withlow-maintenancevegetationsuchassedumandgrass.Theyarelightweight,andsimpletodesign,constructandmaintain.Theyarenotsuitableforregularlytraffickedareasorrecreationalactivity.Extensivesystemshaveaestheticappealandofferecologicalbenefits.

Semi–intensivegreenroofs-Haveadeepergrowingmediumandsupportvegetationsuchasgrasses,perennialsandshrubs.Theycanaccommodatelimitedaccessformaintenanceandlightrecreation.

Intensive green roofs - Haveasignificantlydeepergrowingmediumandsupportawiderangeofflora,includinggrasses,shrubsandsmalltrees.Theyresemblenormalgardensasregardscareandmaintenance, and can be used for recreational activities.

Semi-intensiveandintensivegreenroofsrequirecarefuldesign,andincorporatethefollowingelements:

Growing Medium

Specialist,lightweightmixturesareavailable,incorporatingfiltration,drainage and moisture retention functions.

Drainage Layer

Normallyconsistingofacastellatedplastic(HDPE)sheeting,withfiltrationmembrane.Thislayerpromotestherapidremovalofexcessrainwaterfromtheroof,therebyavoidingsaturationofthegrowningmediumandassociatedincreaseinweight.

Root Barrier

Therootsofgrowingplantscanseriouslydamagewaterproofmembranes,bygrowingintoanysmallcracks,lapjoints,etc.Alumascroot-resistantprotectionsheetisadheredtotheHydrotechmembrane,withalljointssealedbytorching,andmustbecontinueduptheverticalfacesofupstands.

SITEWORK

Roof Waterproofing

TheAlumascVThermVacuumInsulatedSystemshouldbeusedoverthehydrotechhotliquidappliedwaterproofingsystem.

Water Vapour Control

Protectedmembraneroofsareinherentlysafeasregardscondensationrisk.Toassesstheriskofinterstitialcondensationina roof construction, refer to BS 5250: 2002 (Code of Practice for controlofcondensationinbuildings)orBS6229:2003(Flatroofswithcontinuouslysupportedcoverings.CodeofPractice).

Green Roofs

Benefits

Greenroofsareanalternativetoastandardprotectedmembraneroofandoffermanyadvantages.However,precisedesignanddetailingarerequired.

Greenroofscan:

• Reducelevelsofdustandimprovehumidity.

• Provideahabitatattractivetowildlife.

• Create areas for recreational activities.

• Retainrainfallandthereforepreventwatersurgesintothe drainage system.

• Improve sound insulation.

• Provideafinishthatisvisuallymoreattractivethangravelor paving slab ballast.

WATERPROOFING

BeforeinstallingtheAlumascVThermVacuumInsulatedSystem,itisessentialtoensurethatthewaterproofingsystemhasbeeninstalledcorrectlyandthattheroofiswatertight,cleanandleaktested.Thesurfaceofthewaterproofingshouldbesmooth,flatandfreefromprojections.

Insulation Boards

• UsearubbercrumbprotectionlayerundertheAlumascVTherm VacuumInsulatedSystem.Forfurtherinformationpleasecontact theAlumascTechnicalDepartment(seebackcover).

• LayVThermpanelsbreakbondedwherepracticable,withjoints lightlybutted.Ensuretherearenogapsatabutments.

• WhererunsofAlumascVThermVacuumInsulatedSystempanels donotaccuratelyfitthedimensionoftheroof,useinfillpanelsto makeupthedifference.Infillpanelsmustbethesamethicknessas theVThermpanels.

• InstalltheAlumascExtrudedPolystyreneoverlayassoonas possibletoavoidexposingtheAlumascVThermSystemtodirect foottraffic.

• Layanyinfillpanelstoabuttheroofperimeterandanyupstands orroofpenetrationssuchasdrainageoutlets,totakeaccountof building tolerances.

• Insulateupstandsattheroofperimeterandtheinternalfaceof parapets.

• Maintainaminimumdistanceof300mmbetweenthetopofthe insulationupstandandthebottomofthehorizontalroof insulation.

• TakeparticularcarewheninstallingAlumascVThermSystemsin windyconditions.

Alumasc Separator Sheet

• AlwayslayAlumascSeparatorSheetovertheinsulationpanels.

• Whereonerunofseparatorsheetmembranelapsanother, maintainaminimum300mmsideandendoverlaps,inthe direction of drainage.

• Turnuptheseparatorsheetmembraneattheedgeoftheroof insulationandsecureitundertheflashing.

Gravel Ballast

• Installtheballastlayerassoonaspossibletoensurethatthe AlumascSeparatorSheetisalwaysprotectedandnotdamagedby excessiveheatbuild-uporhighwinds.

• Gravelballastshouldbewashed,roundedto20-40diameter,and laidtoaminimumofdepthof50mm.

• Thediameterofthegravelissignificantbecauseasizeof20- 40mmhasbeenfoundtoofferthemosteffectiveresistanceto windscour.RefertoBREDigest311foradvice.

General

•DonotusetheAlumascVThermVacuumInsulatedSystemin associationwithsolvent-basedadhesivesystems.Avoidexposure oftheVThermsystemtonakedflamesorexcessiveheat.

Cutting

•DonotcutorpenetratetheVacuumInsulationPanels.Ensure thesubstrateisclean,dryandlevel,andfreefromsharpobjectsor edges.

• Cuttheinfillpanelswithafine-toothedsaw,orbyscoringwitha sharpknifeandsnappingtheboardoverastraightedgeandthen cuttingthefacingontheotherside.

• Ensureaccuratetrimmingoftheinfillpanelstoachieveclose- buttingjointsandcontinuityofinsulation

Availability

•PleasecontactAlumascSalesDeptforavailabilityofthe AlumascVThermVacuumInsulatedSystem.

Packaging and Storage

•ThepackagingoftheAlumascVThermVacuumInsulatedSystem shouldnotbeconsideredadequateforoutdoorprotection.Store indoorsandraisedoffthefloor.

Health and Safety

•AlumascInsulationproductsarechemicallyinertandsafetouse.

• ASafetyDataSheetisavailableontheAlumascRoofingwebsite.

Warning–donotstandonorotherwisesupportyourweightonthisproductunlessitisfullysupportedbyaloadbearingsurface.

Pleasenotethatthereflectivesurfaceonthisproductisdesignedtoenhanceitsthermalperformance.Assuch,itwillreflectlightaswellasheat,includingultravioletlight.Therefore,ifthispanelisbeinginstalledduringverybrightorsunnyweather,itisadvisabletowearUVprotectivesunglassesorgoggles,andiftheskinisexposedforasignificantperiodoftime,toprotectthebareskinwithaUVblocksun cream.

SITEWORK

Paving Slab Ballast

•Layminimum50mmthickpavingslabs,overAlumascSeparator Sheet,onproprietarypavingslabsupportstomaintaindrainage belowtheslabsandtoensurethatmoisturevapourcanescape.

• Installthepavingslabsandsupportsassoonaspossibletoensure thattheseparatorsheetisalwaysprotectedandtoprevent excessiveheatbuild-uporhighwindsdonotdamagethe insulation panels.

• Ensurethatgapsbetweenpavingslabsandupstandsarefilled withwashedroundedgravel,nominal20-40mmdiameter.

Roof Gardens

• InstalltheAlumascVThermVacuumInsulatedSystemas described previously.

• OverlaythepanelswithAlumascSeparatorSheet–installedas described previously.

• Installafiltrationlayerorcombinedfiltrationlayer/drainage mat.

• Installthegrowingmedium,generally50-200mmdeep. Specialistspraysystemsareavailable,whichallowtheapplication ofthegrowingmediumandgrass/plantseedtobeappliedin one operation.

• Assessthedepthofthegrowingmediumwithregardtowind loadsinaccordancewithBS6399-2:1997(Loadingforbuildings. Codeofpracticeforwindloads),orBS/I.S.EN1991-1-4:2005 (NationalAnnextoEurocode1Actionsonstructures.General Actions.WindActions).

Wheeled / Foot Traffic

• TakecarenottowalkontheVThermvacuuminsulatedinsulation panels.Useaprotectivefootorcrawlboardduringtheinstallation process.

• TheinfillpanelsandtheAlumascExtrudedPolystyreneOverlay maybewalkedon.

PRODUCT DETAILS

Composition

TheVacuumInsulationPanelscomprisearigidvacuuminsulationwithamicroporouscore,whichisevacuated,encasedandsealedinathin,gas-tightenvelope.

Theinfillpanelscompriseahigh-performancerigidextrudedpolystyrene insulation.

Standards and Approvals

TheVIP PanelismanufacturedtothehigheststandardsunderamanagementsystemcertifiedtoISO9001:2008(QualityManagementSystems.Requirements),ISO14001:2004(EnvironmentalManagementSystems.Requirements),BSOHSAS18001:2007(HealthandSafetyManagementSystems.Requirements)andISO50001:2011(EnergyManagementSystems.RequirementswithGuidanceforUse).

Standard Dimensions

TheVacuumInsulationPanelsareavailableinthefollowingstandardsize(s):

Nominal Dimension Availability

Length 300 - 1200 mm

Width 300 - 600 mm

Insulant Thickness 20 - 60 mm

Othersizesmaybeavailabledependentonorderquantity.PleasecontactAlumascRoofingformoredetails.

Compressive Strength

ThecompressivestrengthoftheKingspanOPTIM-Rpanelstypicallyexceeds150kPaat10%compressionwhentestedtoBS/I.S.ENISO826:1996(Thermalinsulatingproductsforbuildingapplication.Determinationofcompressionbehaviour).

Durability

If installed correctly and protected from damage and penetration, theAlumascVThermVacuumInsulatedSystemcanprovidereliablelong-termthermalperformanceoverthelifetimeofthebuilding.

Resistance to Solvents, Fungi & Rodents

TheAlumascVThermVacuumInsulatedSystemshouldnotbeusedinassociationwithsolvent-basedadhesivesystems.Damagedboardsorboardsthathavebeenincontactwithsolventsoracidsshouldnotbeused.

TheinsulationcoreandfacingsusedinthemanufactureoftheAlumascVThermVacuumInsulatedSystemresistattackbymouldandmicrobialgrowth,anddonotprovideanyfoodvaluetovermin.

Fire Performance

TheAlumascVThermVacuumInsulatedSystem,whensubjectedtotheBritishStandardfiretestspecifiedinthetablebelow,willachievetheresultshown,whenthesurfacefinishiseitherminimum50mmgravel ballast or minimum 40 mm paving slabs.

Test Result

BS 476–3: 2004 (External fire exposure roof

test)

Ext. FAA rating

FurtherdetailsonthefireperformanceofproductsmaybeobtainedfromtheAlumascTechnicalServiceDepartment(seebackcover).

Aminimumdistanceof300mmshouldbemaintainedbetweenthetopoftheinsulationupstandandthebottomofthehorizontalroofinsulation.Wallinsulationshouldalsobecarriedupintoparapetsashighastheflatroofinsulationupstand.PleasecontacttheAlumascTechnicalDepartment(seebackcover)forfurtheradvice.

Thermal Properties

ThevaluesdetailedbelowarequotedinaccordancewithBS/I.S.EN12667:2001(Thermalperformanceofbuildingmaterialsandproducts.Determinationofthermalresistancebymeansofguardedhotplateandheatflowmetermethods.Productsofhighandmediumthermalresistance),withallowanceforageingandedgeeffectoftheencapsulatingfilmtoformthedesignvalue.

Thermal Conductivity

TheVacuumInsulationPanelsachieveathermalconductivity(K-value)of0.007W/mK(ageddesignvalueallowingforedgeeffect).

Thermal Resistance

Thermalresistance(R-value)oftheVacuumInsulationPanelsvarieswiththicknessandiscalculatedbydividingthethicknessofthepanel(expressedinmetres)bythethermalconductivity(K).

Insulant Thickness (mm) R ValueThermal Resistance (m2-K/W)

20 2.857

25 3.571

30 4.285

40 5.714

50 7.143

60 8.571

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