Minimum Roof Slope For Shingles

According to this code the minimum slope for asphalt shingles is 17 degrees or two vertical units to twelve units in the horizontal.

Minimum roof slope for shingles.

In case a slope greater than this is necessary then a double underlayment application must be used as per the requirements of the international building code. Asphalt shingles continue to be the most widely installed roof covering option in north america. The roof pitch between 2 12 and 4 12 is considered as a low pitch roof so shingles can be installed in the roof slope between 2 12 and 4 12. What is the minimum slope for an asphalt shingle roof.

Installation on roof slopes below a 2 in 12 pitch is not recommended at all. In 12 0 25 in 12 1 19 built up roof coal tar pitch. 18 43 asphalt shingles with special underlayment requirements 2 in 12. Minimum pitch for corrugated metal roof.

This number corresponds to the number of inches of rise in a 12 foot run. Minimum roof slopes required by roofing material requirements for roof coverings section r905. 9 46 built up roof asphalt. Considering the roof slope requirement is important.

Minimum required slope x in 12 minimum required slope degrees asphalt shingles. Why is 2 12 the minimum. They provide excellent weather resistance great value and now more than ever a tremendous range of beautiful designs and color blends. The asphalt shingle manufactures recommend that you install asphalt shingles on a recommended minimum of 4 in 12 or greater however most manufactures will warrant their shingles down to a 2 in 12 pitch if the recommended installation method is used.

So a 4 12 pitch roof rises 4 inches for every 12 inches of horizontal run. The short simple answer is 2 12 has traditionally been considered the absolute minimum acceptable roof slope suitable for asphalt shingles. Some people recommend not installing asphalt shingles on slopes below 5 12 but a skilled roofer may well be able to make this work. Minimum required roof slope for roofing materials.

Pitch is measured in inches of vertical rise of the roof over one foot 12 inches of horizontal run. A shingle roof like this north dallas garage in the photo above may have a failure no matter how good a job the installer did. The 2 12 number is rise over run or two units of vertical for every 12 units horizontal. That works out to about nine degrees if that works better for you.

Roofing material or system. Minimum roof slope roof pitch r905 2 2 asphalt shingles can only be installed on roof slopes of. Shingles of all types need to have a slope to function properly. There are differing opinions as to the minimum slope for a roof but the generally accepted minimum is 3 12.

Manufacturers of asphalt shingles recommend a pitch of 4 12 or more but the absolute minimum pitch is 2 12. The minimum pitch for shingles is 1 6 which is equivalent to 4 inches rise to 24 inches run.