Minimum Roof Pitch For Architectural Shingles

What precautions need to be taken to install shingles on low slopes.

Minimum roof pitch for architectural shingles.

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. For pitches of 2 5 12 up to 4 12 the roof requires double underlayment. A roof slope of 2 12 up to but not including 4 12 is considered as low in residential construction. So a 4 12 pitch roof rises 4 inches for every 12 inches of horizontal run.

Shingles of all types need to have a slope to function properly. 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. You could also opt for a pvc flat roofing membrane.

Pitch is measured in inches of vertical rise of the roof over one foot 12 inches of horizontal run. 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 slope is considered low slope for shingles. Asphalt shingles continue to be the most widely installed roof covering option in north america.

Clay or cement tiles can be used on a wide range of roof pitches. 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. The 2 12 number is rise over run or two units of vertical for every 12 units horizontal. 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. 4 12 to 20 12 pitches. The recommended minimum roof pitch for shingles is 2 12 or simply two units of vertical rise to every twelve units of horizontal span. The minimum requirement is 2 12.

Slopes above 19 12 are not recommended since tiles on very steep roofs can rattle. 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. 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.