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). |
From inside the book
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... carriers 2.3 . Hailstone molds Contents Page 1 3 3 3 4 4 5 5 5 5 6 19 7 8 2.4 . Specimen construction 3. Procedures 3.1 . Shooting hailstones at roofing 3.2 . Evaluating failure 4. Results 4.1 . Asphalt shingles 4.2 . Built - up roofs ...
... carriers 2.3 . Hailstone molds Contents Page 1 3 3 3 4 4 5 5 5 5 6 19 7 8 2.4 . Specimen construction 3. Procedures 3.1 . Shooting hailstones at roofing 3.2 . Evaluating failure 4. Results 4.1 . Asphalt shingles 4.2 . Built - up roofs ...
Page 3
... carrier ( 6 ) , hailstone molds ( 7 ) , and a triggering mechanism ( 8 ) . The roofing specimen to be tested is ... Carriers The hail carriers were made from 3 - in ( 7.6 cm ) diameter foamed polyethylene cylinders ( Ethafoam - Dow ...
... carrier ( 6 ) , hailstone molds ( 7 ) , and a triggering mechanism ( 8 ) . The roofing specimen to be tested is ... Carriers The hail carriers were made from 3 - in ( 7.6 cm ) diameter foamed polyethylene cylinders ( Ethafoam - Dow ...
Page 4
... carriers - one in gun and one in open to show cavity . nally ( Item 6 fig . 2 ) . Each hemicylinder was truncated at one ... carrier . 2.3 . Hailstone Molds The hailstones were cast in molds made from a silicone casting resin ( RTV - 60 ...
... carriers - one in gun and one in open to show cavity . nally ( Item 6 fig . 2 ) . Each hemicylinder was truncated at one ... carrier . 2.3 . Hailstone Molds The hailstones were cast in molds made from a silicone casting resin ( RTV - 60 ...
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... carrier . The carrier was propelled out of the gun , where the air resistance opened the two halves and permitted the hailstone to travel alone toward the target . As the hailstone hit the first tape it started the counter , and as it ...
... carrier . The carrier was propelled out of the gun , where the air resistance opened the two halves and permitted the hailstone to travel alone toward the target . As the hailstone hit the first tape it started the counter , and as it ...
Common terms and phrases
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