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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... Hailstone 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 ...
... Hailstone 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 ...
Page 1
... hailstones that are relatively small . These small stones can damage crops , but not roofings . However , every year there are a number of storms in which hailstones occur in the range of 111⁄2 to 3 in . ( 3.8 to 7.6 cm ) , or more , in ...
... hailstones that are relatively small . These small stones can damage crops , but not roofings . However , every year there are a number of storms in which hailstones occur in the range of 111⁄2 to 3 in . ( 3.8 to 7.6 cm ) , or more , in ...
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... Hailstone mold . 8. Triggering mechanism . FIGURE 2. perature much below the freezing point of water , the ice that forms does so rapidly and traps air in the process . This forms a milky layer of low - density ice . When an ice ...
... Hailstone mold . 8. Triggering mechanism . FIGURE 2. perature much below the freezing point of water , the ice that forms does so rapidly and traps air in the process . This forms a milky layer of low - density ice . When an ice ...
Page 3
... hailstones drop out as in the frontal storm . This type of storm tends to drop its hailstones at about 6000 ft . Figure 1 is a map of the central United States showing the distribution of storms during the years 1960-1966 in which at ...
... hailstones drop out as in the frontal storm . This type of storm tends to drop its hailstones at about 6000 ft . Figure 1 is a map of the central United States showing the distribution of storms during the years 1960-1966 in which at ...
Page 4
... hailstones at different parts of these materials until failure occurred . 3. Procedures 4. Results TABLE 2. Hail ... hailstones and permitted one size barrel to be used for all of the hailstones . Car- riers with recesses for 111⁄2 ( 3.8 ...
... hailstones at different parts of these materials until failure occurred . 3. Procedures 4. Results TABLE 2. Hail ... hailstones and permitted one size barrel to be used for all of the hailstones . Car- riers with recesses for 111⁄2 ( 3.8 ...
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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