Roof Slope For Asphalt Shingles

Asphalt shingles should never be applied to roof slopes below 2 12 2 of vertical rise for every 12 of horizontal run or 9 5.

Roof slope for asphalt shingles.

The short simple answer is 2 12 has traditionally been considered the absolute minimum acceptable roof slope suitable for asphalt shingles. Minimum roof slope roof pitch r905 2 2. Gaf asphalt shingles combined with the proper underlayment make ideal low slope roof shingles that do an excellent job of preventing water build up and leaking. Also if asphalt shingles are installed on a roof slope of 2 12 to 4 12 it shall be provided with a double underlayment application.

Shingles of all types need to have a slope to function properly. The 2 12 number is rise over run or two units of vertical for every 12 units horizontal. In 12 0 25 in 12 1 19 built up roof coal tar pitch. The maximum slope considered suitable for normal shingle application is 45 degrees or 12 per foot.

The minimum requirement is 2 12. They provide excellent weather resistance great value and now more than ever a tremendous range of beautiful designs and color blends. If a roof slope exceeds this limitation the shingles should be applied by the following recommended method complying with astm d4586. That works out to about nine degrees if that works better for you.

Roofing material or system. Minimum required slope x in 12 minimum required slope degrees asphalt shingles. Asphalt shingles can only be installed on roof slopes of 2 12 or greater. Secure the shingle to the roof deck with fasteners as recommended by the roofing manufacturer.

If a roof slope rise is 4 inches when measured 12 inches along the bottom of the horizontal run the roof slope is said to be 4 12. What are gaf asphalt shingles. 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.

Asphalt shingles continue to be the most widely installed roof covering option in north america. 18 43 asphalt shingles with special underlayment requirements 2 in 12. Additional underlayment protection with special application methods are required when asphalt shingles are installed on a low slope roof following the manufacturer s application instructions. You can measure the roof slope either using tape or smartphone applications.

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 required roof slope for roofing materials. The asphalt shingle roof contractors provide pitch estimator cards to measure the roof slope. There are differing opinions as to the minimum slope for a roof but the generally accepted minimum is 3 12.

9 46 built up roof asphalt. At nelson contracting we proudly offer and install gaf asphalt shingles for both high and low pitch roofs. What is the minimum pitch slope of an asphalt shingle roof.