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
... types of damaging hailstorms are en- countered in the United States [ 5 ] . The most prevalent type is known as the frontal storm . It involves the encounter of a cold , high air mass with a low , moist , warm air mass . The cold air ...
... types of damaging hailstorms are en- countered in the United States [ 5 ] . The most prevalent type is known as the frontal storm . It involves the encounter of a cold , high air mass with a low , moist , warm air mass . The cold air ...
Page 3
... type of storm occurs on the east- ern slopes of the Rocky Mountains ; thus , it is called an orographic storm . A front of warm , moist air hits the base of the mountains , ex- pands upward until the nucleation , freezing and tumbling ...
... type of storm occurs on the east- ern slopes of the Rocky Mountains ; thus , it is called an orographic storm . A front of warm , moist air hits the base of the mountains , ex- pands upward until the nucleation , freezing and tumbling ...
Page 4
... Type. 7. Hailstone mold . 8. Triggering mechanism . FIGURE 2. Hail resistance apparatus . 5 MOD 360 A 1. Test specimen . 2. Timing section . 3. Compressed gas gun . 4. Gas cylinder . 5. Timer . 6. Hailstone carriers - one in gun and one ...
... Type. 7. Hailstone mold . 8. Triggering mechanism . FIGURE 2. Hail resistance apparatus . 5 MOD 360 A 1. Test specimen . 2. Timing section . 3. Compressed gas gun . 4. Gas cylinder . 5. Timer . 6. Hailstone carriers - one in gun and one ...
Page 5
... Type 235 square tab shingles. The ice spheres were stored in a chest - type freezer at about 10 ° F ( -12 ° C ) until ready for use . 91 cm ) decks , representative of those used in construction ( 38 in ( 1 cm ) and 12 in ( 1.3 cm ) ...
... Type 235 square tab shingles. The ice spheres were stored in a chest - type freezer at about 10 ° F ( -12 ° C ) until ready for use . 91 cm ) decks , representative of those used in construction ( 38 in ( 1 cm ) and 12 in ( 1.3 cm ) ...
Page 6
... types of roofing studied . 4.1 . Asphalt Shingles When applied according to the recommenda- tions of their manufacturers , Type 235 square- tab shingles have three regions of different vulnerability : ( 1 ) The tab edges , ( 2 ) The sur ...
... types of roofing studied . 4.1 . Asphalt Shingles When applied according to the recommenda- tions of their manufacturers , Type 235 square- tab shingles have three regions of different vulnerability : ( 1 ) The tab edges , ( 2 ) The sur ...
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