Roof Slope For Asphalt Shingles

The 2 12 number is rise over run or two units of vertical for every 12 units horizontal.

Roof slope for asphalt shingles.

There are differing opinions as to the minimum slope for a roof but the generally accepted minimum is 3 12. What is the minimum pitch slope of an asphalt shingle roof. 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. Installation on roof slopes below a 2 in 12 pitch is not recommended at all.

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. Asphalt shingles continue to be the most widely installed roof covering option in north america. Minimum roof slope roof pitch r905 2 2. That works out to about nine degrees if that works better for you.

Asphalt shingles can only be installed on roof slopes of 2 12 or greater. Roofing material or system. In 12 0 25 in 12 1 19 built up roof coal tar pitch. At nelson contracting we proudly offer and install gaf asphalt shingles for both high and low pitch roofs.

What is the minimum slope for an asphalt shingle roof. The asphalt shingle roof contractors provide pitch estimator cards to measure the roof slope. 18 43 asphalt shingles with special underlayment requirements 2 in 12. 9 46 built up roof asphalt.

Shingles of all types need to have a slope to function properly. 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. Some people recommend not installing asphalt shingles on slopes below 5 12 but a skilled roofer may well be able to make this work.

The maximum slope considered suitable for normal shingle application is 45 degrees or 12 per foot. What are gaf asphalt shingles. Minimum required slope x in 12 minimum required slope degrees asphalt shingles. This number corresponds to the number of inches of rise in a 12 foot run.

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. If a roof slope exceeds this limitation the shingles should be applied by the following recommended method complying with astm d4586. You can measure the roof slope either using tape or smartphone applications. This means for every 12 horizontal units the roof must rise a minimum of 2 vertical units.

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. 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.