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 1
... energy is reached at which damage occurs . This level lies in the range of 12 to 2 inch ( 3.8-5.1 cm ) hailstones for most prepared roofings . ( b ) Because of the ways in which prepared roofings are applied , most products have areas ...
... energy is reached at which damage occurs . This level lies in the range of 12 to 2 inch ( 3.8-5.1 cm ) hailstones for most prepared roofings . ( b ) Because of the ways in which prepared roofings are applied , most products have areas ...
Page 3
... energy of damage . The velocities were con- trolled by the size of the charge in the blank cartridges used in the launcher . Because of the difficulties in controlling the velocities of the hailstones , an air - operated piston was ...
... energy of damage . The velocities were con- trolled by the size of the charge in the blank cartridges used in the launcher . Because of the difficulties in controlling the velocities of the hailstones , an air - operated piston was ...
Page 5
... energy Diameter inches ст ft / s mi / hr ( m / sec ) ft lbs Joules 1 ( 2.5 ) 73 50 ( 22.3 ) < 1 ( < 1.36 ) 114 ( 3.2 ) 82 56 ( 25.0 ) 4 ( 5.42 ) 11/2 ( 3.8 ) 90 61 ( 27.4 ) 8 ( 10.85 ) 134 ( 4.5 ) 97 66 ( 29.6 ) 14 ( 18.96 ) 2 ( 5.1 ) ...
... energy Diameter inches ст ft / s mi / hr ( m / sec ) ft lbs Joules 1 ( 2.5 ) 73 50 ( 22.3 ) < 1 ( < 1.36 ) 114 ( 3.2 ) 82 56 ( 25.0 ) 4 ( 5.42 ) 11/2 ( 3.8 ) 90 61 ( 27.4 ) 8 ( 10.85 ) 134 ( 4.5 ) 97 66 ( 29.6 ) 14 ( 18.96 ) 2 ( 5.1 ) ...
Page 6
... energy . From these results , it would seem that the solidly sup- ported roofings performed better than those with some soft underlying layer in their con- struction . This observation is consistent with the fact that shingle materials ...
... energy . From these results , it would seem that the solidly sup- ported roofings performed better than those with some soft underlying layer in their con- struction . This observation is consistent with the fact that shingle materials ...
Page 7
... any of the hailstones . ( The slag was retained by cheese cloth when the decks were tested in vertical positions ) . The hailstone energy was dissipated in scattering Hail damage indentation size ⚫ Hailstone size , in ( 7.
... any of the hailstones . ( The slag was retained by cheese cloth when the decks were tested in vertical positions ) . The hailstone energy was dissipated in scattering Hail damage indentation size ⚫ Hailstone size , in ( 7.
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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