Minimum Pitch For Slope Roof

If a roof slope rises say 4 inches when measured 12 inches along the bottom of a horizontal roof truss the roof slope is said to be 4 12.

Minimum pitch for slope roof.

However you can only use this pitch with built up roofing or specialized synthetic roofing. What is the minimum pitch slope of an asphalt shingle roof. But since there is still a wide variety of slate roofing systems there are occasions when the minimum pitch can go down to as low as 15 0 depending on the uniqueness of the roof. However roof pitch is technically measured and defined differently.

The minimum pitch for a roof is 1 4 12 which translates to 1 4 inch rise to 12 inches of run. Note that roof pitch is sometimes used in parallel with roof slope. With regards to the pitch the building standard code bs 5534 recommends a minimum pitch of 20 0 for slate roofs. Shingles of all types need to have a slope to function properly.

The standard of lower pitch actually ranges between 1 12 to 5 12. The minimum roof slope allowed by code for any type of roof is in 12 applicable only to coal tar pitch roof systems. The metal roof minimum slope doesn t stray far from other building with different material. The minimum pitch is typically 3 12 meaning the roof should rise 3 inches for every 12 inches of horizontal foot.

The 2 12 number is rise over run or two units of vertical for every 12 units horizontal. The following table provides the minimum required allowable roof slope for each type of roofing material mentioned in the code.