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
Page 4
... center of a cylin- drical polyethylene container of suitable size . The casting resin was deaerated , poured into the mold and cured . The following day the cast- ing was removed from the polyethylene con- tainer and sliced through with ...
... center of a cylin- drical polyethylene container of suitable size . The casting resin was deaerated , poured into the mold and cured . The following day the cast- ing was removed from the polyethylene con- tainer and sliced through with ...
Page 5
... centers . The built - up roofing specimens , 1 ft ( 30.5 cm ) square , were solidly mopped to 12 in ( 1.3 cm ) plywood or 1 in ( 2.5 cm ) asbestos cement board ( to simulate a concrete deck ) or to various types of insulation mopped ...
... centers . The built - up roofing specimens , 1 ft ( 30.5 cm ) square , were solidly mopped to 12 in ( 1.3 cm ) plywood or 1 in ( 2.5 cm ) asbestos cement board ( to simulate a concrete deck ) or to various types of insulation mopped ...
Page 6
... centers , but both developed felt damage in the other two areas with 11 / 4 - in ( 3.2 cm ) hailstones . No direct comparison can be made between these aged shingles and unexposed ones be- cause of changes in design and production . How ...
... centers , but both developed felt damage in the other two areas with 11 / 4 - in ( 3.2 cm ) hailstones . No direct comparison can be made between these aged shingles and unexposed ones be- cause of changes in design and production . How ...
Page 9
... Center Unsupported in em in ст in cm 11/2 ( 3.8 ) 14 ( 4.5 ) ( 4.5 ) 2 ( 5.1 ) 2 ( 5.1 ) 14 ( 4.5 ) 1/4 ( 4.5 ) ( 5.1 ) 2 ( 5.1 ) ( 5.1 ) 112 ( 3.8 ) ( 3.8 ) 14 ( 4.5 ) ( 3.8 ) 112 ( 3.8 ) ( 5.1 ) 14 ( 4.5 ) ( a ) All roofing materials ...
... Center Unsupported in em in ст in cm 11/2 ( 3.8 ) 14 ( 4.5 ) ( 4.5 ) 2 ( 5.1 ) 2 ( 5.1 ) 14 ( 4.5 ) 1/4 ( 4.5 ) ( 5.1 ) 2 ( 5.1 ) ( 5.1 ) 112 ( 3.8 ) ( 3.8 ) 14 ( 4.5 ) ( 3.8 ) 112 ( 3.8 ) ( 5.1 ) 14 ( 4.5 ) ( a ) All roofing materials ...
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... Center for Radiation Research , the Center for Computer Sciences and Technology , and the Office for Information Programs . THE INSTITUTE FOR BASIC STANDARDS provides the central basis within the United States of a complete and ...
... Center for Radiation Research , the Center for Computer Sciences and Technology , and the Office for Information Programs . THE INSTITUTE FOR BASIC STANDARDS provides the central basis within the United States of a complete and ...
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