Roof Deck Slope Ratio

A ratio of 1 1 62 is known as the golden ratio and therefore the vast majority of roof pitch in degrees charts you see will be working to this ratio at the very least.

Roof deck slope ratio.

3 use the divided measurement as the total amount of slope for the deck in inches. The minimum pitch for. A deck that projects 9 feet out. Then we were able to correct the owner s ponding water concerns.

If the deck extends 9 feet out from the house the divided measurement is 1 8. Flat roofs which aren t perfectly flat require a small slope to allow for water runoff. We were able to make new crickets to the existing roof membrane providing positive water flow to the drains. Match roof material and use appropriate slope match the roofing on the covered porch with the main roof.

Often you express roof pitch as the ratio between the rise and the run in the form of x 12. A minimum slope of 1 50 1 4 in 12 is strongly recommended. 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. Gradation of the bedding sand for pedestrian applications should conform to astm c 33 7 or csa a23 1 fa 1 8.

The risk of saturated bedding sand is reduced by adequate slope of the roof structure and correct sand gradation. Sand requires at least a minimum deck slope of 2 to drain. You can divide roofs into these categories.