Minimum Roof Slope For Shingles

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.

Minimum roof slope for shingles.

18 43 asphalt shingles with special underlayment requirements 2 in 12. There are differing opinions as to the minimum slope for a roof but the generally accepted minimum is 3 12. So a 4 12 pitch roof rises 4 inches for every 12 inches of horizontal run. Minimum pitch for corrugated metal roof.

Shingles of all types need to have a slope to function properly. Manufacturers of asphalt shingles recommend a pitch of 4 12 or more but the absolute minimum pitch is 2 12. Why is 2 12 the minimum. Minimum required roof slope for roofing materials.

This number corresponds to the number of inches of rise in a 12 foot 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. In 12 0 25 in 12 1 19 built up roof coal tar pitch. Asphalt shingles continue to be the most widely installed roof covering option in north america.

Determine the minimum slope of the roof based on the roofing material. Pitch is measured in inches of vertical rise of the roof over one foot 12 inches of horizontal run. That works out to about nine degrees if that works better for you. What is the minimum slope for an asphalt shingle roof.

The 2 12 number is rise over run or two units of vertical for every 12 units horizontal. Minimum required slope x in 12 minimum required slope degrees asphalt shingles. The minimum pitch for shingles is 1 6 which is equivalent to 4 inches rise to 24 inches run. According to this code the minimum slope for asphalt shingles is 17 degrees or two vertical units to twelve units in the horizontal.

Now lets get into the minimum roof slope requirements based on the. The short simple answer is 2 12 has traditionally been considered the absolute minimum acceptable roof slope suitable for asphalt shingles. The minimum requirement is 2 12. 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.

Roofing material or system. 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. Minimum roof slopes required by roofing material requirements for roof coverings section r905. Minimum roof slope roof pitch r905 2 2 asphalt shingles can only be installed on roof slopes of.

9 46 built up roof asphalt. They provide excellent weather resistance great value and now more than ever a tremendous range of beautiful designs and color blends.