Minimum Roof Pitch For Architectural Shingles

The 2 12 number is rise over run or two units of vertical for every 12 units horizontal.

Minimum roof pitch for architectural shingles.

Asphalt shingles continue to be the most widely installed roof covering option in north america. Pitch is measured in inches of vertical rise of the roof over one foot 12 inches of horizontal run. Asphalt shingles should never be applied to roof slopes below 2 12 2 of vertical rise for every 12 of horizontal run or 9 5. So a 4 12 pitch roof rises 4 inches for every 12 inches of horizontal run.

Therefore the asphalt manufactures base their warranties around the minimum recommended pitch of 4 in 12. Slopes above 19 12 are not recommended since tiles on very steep roofs can rattle. The minimum pitch for a roof is 1 4 12 which translates to 1 4 inch rise to 12 inches of run. The minimum requirement is 2 12.

However you can only use this pitch with built up roofing or specialized synthetic roofing. 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. 4 12 to 20 12 pitches. For low slopes as well as any other slope your local building department should be contacted.

What precautions need to be taken to install shingles on low slopes. Asphalt shingles installed on a slope below the recommended roof pitch asphalt composition shingles are designed to be installed on roof slopes greater than a 4 in 12 pitch. What is the minimum slope for an asphalt shingle roof the short simple answer is 2 12 has traditionally been considered the absolute minimum acceptable roof slope suitable for asphalt shingles. Additional underlayment protection with special application methods are required when asphalt shingles are installed on a low slope roof following the manufacturer s application instructions.

What is the minimum pitch slope of an asphalt shingle roof. A roof slope of 2 12 up to but not including 4 12 is considered as low in residential construction. You could also opt for a pvc flat roofing membrane. What slope is considered low slope for shingles.

Clay or cement tiles can be used on a wide range of roof pitches. For pitches of 2 5 12 up to 4 12 the roof requires double underlayment. Tuesday september 11 2018 manufacturers of asphalt shingles recommend a pitch of 4 12 or more but the absolute minimum pitch is 2 12. 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.