Roof Slope Slab

Use a scratch template typically a piece of 2 by 4 or 2 by 6 lumber equal to the specified slab thickness with stakes attached to the top surface at each end or a string line across the top of the forms to.

Roof slope slab.

Convert the change of height over the distance into a percentage pitch using the following equation. A solid slab of concrete capping the top of your house. Percentage pitch height change length x 100. For example the florida based company hurricane proof systems offers a 7 inch 18 centimeter slab of concrete in three layers.

Aci 117 90 st andard specifications for tolerances for concrete construction and materials gives a level alignment tolerance of 3 4 inch for top of slab elevation of slabs on grade. For example a slope 20 feet long that drops by 1 1 2 feet has a percentage pitch of 7 5 percent 1 5 20 x 100 7 5. Hips and valleys have to be engineered and a lot of it is using experience and professional judgment on the hoffman home king spec ed a steel i beam at the ridge line with the lite deck running perpendicular to the ridge. Sloping slabs under gravity load would be subjected to bending and axial thrust.

If the problem is statically determinate the equilibrium equations would. Exact specifications vary but most concrete roofs are several inches thick. Based on the boundary condition you can determine the axial thrust and the bending moment. A concrete roof is exactly what it sounds like.