b'SOLAR REFLECTIVITY 50Results and Findings 45Collecteddataandmodeling40showedthatreflectedsolarradia- 35tion from the curtainwall assemblyC) Temperature ( C) Temperature ( o o 30increasedroofsurfacetempera- JANUARY 29, 25turesabovenormalvaluesbyas2020 20little as 10C and as much as 30C.15The range in temperature increase10revealedthecomplexrelationship5between the roof surface (colour,0and presence or absence of over- Grey White Black Brown Pavers Gravelburden) and adjacent wall finishes,Roof Surfaceglazing,shadowing,timeofday120and the local climate and weather100conditions. Interestingly, the highly reflectivemullionsontheAERL80clerestorywindowsraisedroof surfacetemperaturesmorethanJULY 26, 60the glass surfaces; modeling of an2020 40opaque wall and a corrugated metal wallsurfaceprojectedlowerroof20surfacetemperaturesunderthe same time/space vectors (Figure 7). 0 Grey White Black Brown Pavers GravelThefollowinggeneralizedRoof SurfaceprinciplesemergedfromthedataClerestory Windows: Max Temp Clerestory Windows: Field Temperature Roof Without Windowsanalysis and modeling: Figure 8: Comparative data between January and July 2020. Note that the roof surface temperatures in January still reaches 1. Roofs oriented to face south40C or more (black membrane), and well above 25C for grey and especially brown surfaces. (Evoke/Morrison Hershfield).andsouthwestwillbemost impactedbyreflectivewall surfaces.2. Higher roof surface tempera- Menzies High QualityturesgeneratedbyreflectedMetal Flashings sunlightcanraiseinternal roofsystemtemperatures,www.menzies-metal.com Innovative Roofing Solutionswhich maysince 1978 a) induceabove-normalexpansionandcontrac- Roof to WallEave Flashing tionofthematerialsFlashing below the membrane.Curved FlashingsOutside Corners b) accelerate the revelationofentrappedmoistureRoof Gable/Sundeck Flashing or workmanship issues. W Valley Flashing3.Reflectionsoffmetalcan bemoredestructivethanCurved FlashingsInside Corners reflectedsunlightfromglass (Figure 7). High quality flashings with industry leading lead times4.Regardlessoftheseason, Durable up to 22 gauge material (18 gauge galvanized)reflectedlightstillraisesthe Prepainted both sidesmembranesurfacetempera-Available in various coloursture significantly (Figure 8).Stock profiles roll formed for consistent quality Custom flashings available5. Membranewillagemorerapidlyandmayexperience1.800.665.8840 localizeddamage.Thiswill www.rcabc.org l27'