Least Roof Pitch

Common roof pitches and equivalent grade degree and radian angles.

Least roof pitch.

The minimum requirement is 2 12. However you can only use this pitch with built up roofing or specialized synthetic. The minimum slope for lapped non soldered seam metal roofs with applied lap sealant shall be one half unit vertical in 12 units horizontal 4 percent slope. Roof pitch refers to the amount of rise a roof has compared to the horizontal measurement of the roof called the run.

There are advantages and disadvantages to having a steep pitch versus a shallow or low pitch the most obvious of which is the roof s ability to shed or withstand. 25 12 to 3 12 roof pitches. The 2 12 number is rise over run or two units of vertical for every 12 units horizontal. There are some standing seam metal roofing options available from atas and other manufacturers that can be installed on a roof with pitch of 1 12.

In snowy areas your roof should be at least 10 12 40 to allow snow to shed while the safest roof pitch in very windy areas is between 4 12 6 12 18 5 26 5. With regards to the pitch the building standard code bs 5534 recommends a minimum pitch of 200 for slate roofs. You could also opt for a pvc flat roofing membrane. Most roof s have a pitch in the 4 12 to 9 12 range.

To see how pitch impacts the look of a garage and changes cost click the design center button on our pole barn kits page. The smallest pitch of a roof is 0 5 12. In roofing it is expressed in inches of vertical rise over inches of horizontal run. A 4 12 pitch being 4 inches of vertical rise over one foot or 12 inches of horizontal run.

What is the smallest pitch of a roof. Minimum roof pitch the minimum pitch for a roof is 1 4 12 which translates to 1 4 inch rise to 12 inches of run. The minimum slope for lapped non soldered seam metal roofs without applied lap sealant shall be three units vertical in 12 units horizontal 25 percent slope. 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.

Roof pitches with lower angles such as 1 12 up to 3 12 are found in more urban contemporary style houses and in industrial buildings and shacks. That works out to about nine degrees if that works better for you. A pitch over 9 12 is considered a steep slope roof between 2 12 and 4 12 is considered a low slope roof and less than 2 12 is considered a flat roof. So you would need to pick the right option as most regular standing seam metal roofs will require a roof pitch of 2 12 or even 3 12 at a minimum.