Hail Resistance of Roofing ProductsBuilding Research Division, U.S. Institute for Applied Technology, 1969 - 9 pages A test was developed for evaluating the hail resistance of roofings, in which synthetic hailstones (ice spheres) of various sizes were shot at roof assemblies at their free-fall terminal v * elocities.Indentations, granule loss and roofing fracture were observed.The principal conclusion is that:All roofing materials have some resistance to hail damage, but as the size of the hail increases, a level of impact energy is reached at which damage occurs.This level lies in the range of 1 1/2 to 2 inch (3.8-5.1 cm) hailstones for most prepared roofings.(Author). |
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Page 5
... Hailstones at Roofing The specimen on its deck was held against the backstop in figure 2 with large C clamps . The 1 - in ( 2.5 cm ) paper computer tapes were hooked to the microswitches and fastened to the top of the timing frame with ...
... Hailstones at Roofing The specimen on its deck was held against the backstop in figure 2 with large C clamps . The 1 - in ( 2.5 cm ) paper computer tapes were hooked to the microswitches and fastened to the top of the timing frame with ...
Page 6
... hailstones . Only small , superficial in- 114 - in ( 3.2 cm ) hailstones . The larger size hail- stones produced progressively larger dents . In general , the smaller hailstones produced cir- cular indentations approximating one half ...
... hailstones . Only small , superficial in- 114 - in ( 3.2 cm ) hailstones . The larger size hail- stones produced progressively larger dents . In general , the smaller hailstones produced cir- cular indentations approximating one half ...
Page 7
Sidney H. Greenfeld. hailstones on the solidly supported areas . Simi- larly , three other shingles , all Class A , based on glass mat felts showed no felt damage on their obverse sides with hailstones below 2 in ( 5.1 cm ) in diameter ...
Sidney H. Greenfeld. hailstones on the solidly supported areas . Simi- larly , three other shingles , all Class A , based on glass mat felts showed no felt damage on their obverse sides with hailstones below 2 in ( 5.1 cm ) in diameter ...
Page 8
... Hailstone size , in ( cm ) 11/2 ( 3.8 ) 1 ( 4.5 ) 2 ( 5.1 ) 21/2 ( 6.4 ) in cm in em in em in ст Roof construction ( 1 ) Base ... hailstones up to and including 212 - in ( 6.4 cm ) in diameter . 4.3 . Nonbituminous Roofing A number of ...
... Hailstone size , in ( cm ) 11/2 ( 3.8 ) 1 ( 4.5 ) 2 ( 5.1 ) 21/2 ( 6.4 ) in cm in em in em in ст Roof construction ( 1 ) Base ... hailstones up to and including 212 - in ( 6.4 cm ) in diameter . 4.3 . Nonbituminous Roofing A number of ...
Page 9
... hailstones larger than 21⁄2 in ( 6.4 cm ) . Note tested . All roofings tested were vulnerable to hail damage . As ... hailstones . ( j ) The sheet metal roofing was dented by all sizes of hailstones used . Deck cracking oc- curred when ...
... hailstones larger than 21⁄2 in ( 6.4 cm ) . Note tested . All roofings tested were vulnerable to hail damage . As ... hailstones . ( j ) The sheet metal roofing was dented by all sizes of hailstones used . Deck cracking oc- curred when ...
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15 cents air gun apparatus Applied Technology areas of different Asbestos cement asphalt flood coat Asphalt Roofing asphalt shingles automatic data processing building damage Building Research Building Science Series Built-up roofs Bureau of Standards Cement and Concrete Center Class C shingle Coal tar Concrete Properties cracking cylinder dense decks dents DEPARTMENT OF COMMERCE diameter different vulnerability felt damage Fiberboard on 1-in Foamboard free-fall terminal velocity freezing ft 61 cm Gas cylinder Glass fiber insulation hail damage hail resistance hailstone carrier Hailstone Molds Hailstorms ice spheres indentation Institute for Applied interply asphalt Interrelations Between Cement Joules kg/m² kg/m³ large hailstones launcher lb/sq Meteorol microswitches National Bureau Nonbituminous Roofing organic felt polyethylene Portland Cement prepared roofings reported Resistance of Roofing resistant to hail shingles showed Sidney H sizes of hailstones slag solidly supported areas specimen steel decking substrates tested Type 235 shingles U.S. DEPARTMENT U.S. Government Printing velocity 9 ст