How Much Pitch For A Tin Roof

Minimum pitch for corrugated metal roof.

How much pitch for a tin roof.

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. The picture below shows the pitch of a 7 12 roof slope meaning that for 12 of horizontal measurement roof run the vertical measurement roof rise is 7. 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.

Manufacturers specify a minimum pitch for each of the profiles they offer and sometimes they can be installed at a lower pitch if special underlayment or installation procedures are followed. The rules can occasionally be broken but generally you should not exceed the low range of the recommendation. Just like other metal roofs the minimum pitch for a corrugated metal roof largely depends on the profile of the roof. For example wood and slate shingles might work for roofs steeper than the top recommendation of 12 12 but you should not install them below the 4 12 lower range.

The table below shows common roof pitches and the equivalent grade degrees and radians for each. 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. This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement. 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.

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. Most roof materials have a recommended pitch range for which they are most appropriate. However you can only use this pitch with built up roofing or specialized synthetic roofing.