Minimum Slope For Asphalt Shingles Roof

All asphalt shingle roofs with a pitch of 4 12 or more have an underlayment of 15 lb.

Minimum slope for asphalt shingles roof.

Considering the roof slope requirement is important. For those who don t understand the roof pitch number here is a way to envision it. 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. 18 43 asphalt shingles with special underlayment requirements 2 in 12.

Asphalt shingles continue to be the most widely installed roof covering option in north america. Asphalt shingles minimum roof slope roof pitch r905 2 2. Asphalt felt paper that is tacked to the roof sheathing. Minimum required roof slope for roofing materials.

In 12 0 25 in 12 1 19 built up roof coal tar pitch. This number corresponds to the number of inches of rise in a 12 foot run. This means for every 12 horizontal units the roof must rise a minimum of 2 vertical units. The minimum requirement is 2 12.

That works out to about nine degrees if that works better for you. Minimum required slope x in 12 minimum required slope degrees asphalt shingles. Minimum slope for asphalt shingles. Therefore the asphalt manufactures base their warranties around the minimum recommended pitch of 4 in 12.

Asphalt shingles can only be installed on roof slopes of 2 12 or greater. For example if it is a very low slope water including snowmelt or. Shingles of all types need to have a slope to function properly. 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.

Asphalt composition shingles are designed to be installed on roof slopes greater than a 4 in 12 pitch. 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. What is the minimum pitch slope of an asphalt shingle roof.

Roofing material or system. The requirements for an asphalt shingles roof are contained in the international building code. The minimum slope for an asphalt shingle roof is 2 12. They provide excellent weather resistance great value and now more than ever a tremendous range of beautiful designs and color blends.

Why is 2 12 the minimum. There are differing opinions as to the minimum slope for a roof but the generally accepted minimum is 3 12.