Roof Deck Slope Ratio

Roof slope created a simple and great fix to a project were crickets were missed and ponding water became an issue for an owner.

Roof deck slope ratio.

Generally such roofs have a pitch ranging from 1 2 12 to 2 12. Often you express roof pitch as the ratio between the rise and the run in the form of x 12. Gradation of the bedding sand for pedestrian applications should conform to astm c 33 7 or csa a23 1 fa 1 8. If the deck extends 9 feet out from the house the divided measurement is 1 8.

A minimum slope of 1 50 1 4 in 12 is strongly recommended. The risk of saturated bedding sand is reduced by adequate slope of the roof structure and correct sand gradation. Determine the minimum slope of the roof based on the roofing material. Tapered slope insulation products can only be used to provide slope if any differences from level in the roof deck are less than the percentage of slope provided by the insulation.

A deck that projects 9 feet out. Sand requires at least a minimum deck slope of 2 to drain. Then we were able to correct the owner s ponding water concerns. We were able to make new crickets to the existing roof membrane providing positive water flow to the drains.

Flat roofs which aren t perfectly flat require a small slope to allow for water runoff. Match roof material and use appropriate slope match the roofing on the covered porch with the main roof. You can divide roofs into these categories.