Minimum Slope For Asphalt Shingles Roof

Roofing material or system.

Minimum slope for asphalt shingles roof.

For example if it is a very low slope water including snowmelt or. Asphalt shingles can only be installed on roof slopes of 2 12 or greater. Asphalt shingles continue to be the most widely installed roof covering option in north america. In 12 0 25 in 12 1 19 built up roof coal tar pitch.

Some people recommend not installing asphalt shingles on slopes below 5 12 but a skilled roofer may well be able to make this work. They provide excellent weather resistance great value and now more than ever a tremendous range of beautiful designs and color blends. The 2 12 number is rise over run or two units of vertical for every 12 units horizontal. Asphalt shingles minimum roof slope roof pitch r905 2 2.

But shingle roofing is not watertight in the sense that standing water or wind driven water on a low slope roof can work its way up between the laps which is the reason for the minimum 2 12 slope. Why is 2 12 the minimum. What is the minimum pitch slope of an asphalt shingle roof. All asphalt shingle roofs with a pitch of 4 12 or more have an underlayment of 15 lb.

The minimum slope for an asphalt shingle roof is 2 12. The requirements for an asphalt shingles roof are contained in the international building code. 9 46 built up roof asphalt. The short simple answer is 2 12 has traditionally been considered the absolute minimum acceptable roof slope suitable for asphalt shingles.

Minimum slope for asphalt shingles. For those who don t understand the roof pitch number here is a way to envision it. There are differing opinions as to the minimum slope for a roof but the generally accepted minimum is 3 12. Minimum required roof slope for roofing materials.

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. That works out to about nine degrees if that works better for you. Asphalt composition shingles are designed to be installed on roof slopes greater than a 4 in 12 pitch. Asphalt felt paper that is tacked to the roof sheathing.

This means for every 12 horizontal units the roof must rise a minimum of 2 vertical units. 18 43 asphalt shingles with special underlayment requirements 2 in 12. This number corresponds to the number of inches of rise in a 12 foot run. According to this code the minimum slope for asphalt shingles is 17 degrees or two vertical units to twelve units in the horizontal.

Shingles of all types need to have a slope to function properly. Therefore the asphalt manufactures base their warranties around the minimum recommended pitch of 4 in 12.