b'T&R UPDATEWhat this means to roofing professionals is that they need to be careful not to convey, promise or guarantee to a building owner that the 3-year aged value from CRRC testing will be accurate.Photo 6Chemicals from manufacturing operations under the roof are ejected onto the roof by the vent stack. Solar reflectivity in this area was severely lowered. building ownerPhoto 7that the 3-yearDust from desert climates settled aged value fromand adhered to CRRC testing willPVC membranes be accurate. Thisdramatically research and otherslowering solar Photo 8 reflectivity. A few A unique case wherelike it show thatdrops of perspiration the adhesive wasnot to be the case.and manual pressure switched to alloweasily brought back for a gypsum basedThe reflectivitythe underlying white coverboard arounddata manufacturersmembrane. When the stairs. The different membraneprovide, from theasked, local roofers adhesive clearly hasCRRC-S100 teststated washing was a negative impactprotocol remainsfutile, as this dust on solar reflectivity,would return within compared to the fielda good metric forweeks.of the roof. roof membrane Photos 110 show these various deleterious conditionscomparisons and that the author observed during this study. These samemeeting prescriptive building code requirements. More conditions roofing professionals observe every day. specifically it allows consumers and specifiers to make educated comparisons about the long term solar reflectivity Therefore, based on the observations made during this fieldperformance between different roof membranes; as they study, the author with combined decades of experiencewere tested under the same conditions. Ergo, one could and thousands of roofs observed believes that deleteriouscompare the aged reflectivity of three different single-ply conditions such as these combine in almost infinitesheets, perhaps of the same polymer type, perhaps not, and combinations on our in-service roofs. As such a prescribedmake educated comparisons about their aged reflectivity aging test, does not adequately capture these effects.performance. But alas, each membrane may soil differently What this means to roofing professionals is that they needwhen it is installed and be subject to the numerous variables to be careful not to convey, promise or guarantee to aabove. www.mrca.orgMidwest Roofer 35'