Minimum Roof Pitch For Asphalt Shingles

Minimum slope for asphalt shingles.

Minimum roof pitch for asphalt shingles.

Asphalt shingles require a minimum roof pitch of 2 12 or greater. Asphalt composition shingles are designed to be installed on roof slopes greater than a 4 in 12 pitch. Metal roof shingles require a minimum roof pitch of 3 12 or greater. 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.

The requirements for an asphalt shingles roof are contained in the international building code. What precautions need to be taken to install shingles on low slopes. They provide excellent weather resistance great value and now more than ever a tremendous range of beautiful designs and color blends. Clay and concrete tile requires a minimum roof pitch of 2 1 2 12 or greater.

For those who don t understand the roof pitch number here is a way to envision it. Fortunately the requirements are quite accommodating. A roof slope of 2 12 up to but not including 4 12 is considered as low in residential construction. Asphalt shingles do require that you have a minimum pitch to your roof.

The short simple answer is 2 12 has traditionally been considered the absolute minimum acceptable roof slope suitable for asphalt shingles. Considering the roof slope requirement is important. They won t be appropriate for all roofs. 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. The minimum roof slope allowed by code for any type of roof is in 12 applicable only to coal tar pitch roof systems. The minimum slope for an asphalt shingle roof is 2 12. The 2 12 number is rise over run or two units of vertical for every 12 units horizontal.

If you re having asphalt shingles put on your roof you will have to have a minimum slope. Asphalt shingles continue to be the most widely installed roof covering option in north america. Asphalt felt paper that is tacked to the roof sheathing. That works out to about nine degrees if that works better for you.

For low slopes as well as any other slope your local building department should be contacted. Shingles of all types need to have a slope to function properly. All asphalt shingle roofs with a pitch of 4 12 or more have an underlayment of 15 lb. What is the minimum pitch slope of an asphalt shingle roof.

What slope is considered low slope for shingles. Let us recap on the minimum roof pitch required for each type of roofing material. According to this code the minimum slope for asphalt shingles is 17 degrees or two vertical units to twelve units in the horizontal. Therefore the asphalt manufactures base their warranties around the minimum recommended pitch of 4 in 12.

For example if it is a very low slope water including snowmelt or.