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.

A roof slope of 2 12 up to but not including 4 12 is considered as low in residential construction. Slopes above 19 12 are not recommended since tiles on very steep roofs can rattle. 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. 4 12 to 20 12 pitches.

What precautions need to be taken to install shingles on low slopes. 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. 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. Therefore the asphalt manufactures base their warranties around the minimum recommended pitch of 4 in 12.

You could also opt for a pvc flat roofing membrane. What slope is considered low slope for shingles. The recommended minimum roof pitch for shingles is 2 12 or simply two units of vertical rise to every twelve units of horizontal span. 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.

The minimum requirement is 2 12. So a 4 12 pitch roof rises 4 inches for every 12 inches of horizontal run. Tuesday september 11 2018 manufacturers of asphalt shingles recommend a pitch of 4 12 or more but the absolute minimum pitch is 2 12. 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.

For pitches of 2 5 12 up to 4 12 the roof requires double underlayment. Shingles of all types need to have a slope to function properly. It is important for shingle roofs to function properly and one method of ensuring that this is achieved is to observe the pitch requirements for the shingles. Pitch is measured in inches of vertical rise of the roof over one foot 12 inches of horizontal run.

For low slopes as well as any other slope your local building department should be contacted. The minimum pitch for a roof is 1 4 12 which translates to 1 4 inch rise to 12 inches of run. What is the minimum pitch slope of an asphalt shingle roof. Asphalt shingles continue to be the most widely installed roof covering option in north america.