Roof ballast block
AssigneeRoofblok Limited
InventorsJohn V. Burgoyne, Thomas E. Phalen, Jr.
Life of this patent
Estimating the term…
Abstract
A roof ballast block having generally rectangular top and bottom faces and two parallel edges bevelled at substantially identical angles of 12.degree. to 23.degree. from the vertical, the remaining two edges being substantially vertical, the block having a plurality of parallel spaced channels in its bottom face and being characterized by a density of 85 to 155 pounds per cubic foot, a compressive strength of at least 2500 psi, a flexure strength of at least 300 psi, and a capability of undergoing at least 100 freeze-thaw cycles without cracking.
Claims4
A roof ballast block having generally rectangular top and bottom faces, and two parallel edge faces bevelled at substantially identical angles of 12.degree. to 23.degree. from the vertical, the remaining two edge faces being parallel and substantially vertical, and having a plurality of parallel spaced channels in its bottom face,
- said block being characterized by a density of 85 to 155 lb. per cu ft., a compressive strength of at least 2500 psi, a flexure tensile strength of at least 300 psi, and a capability of undergoing at least 100 freeze-thaw cycles without cracking.
Dependencies are inferred from the claim text.