12 Asphalt Shingle Roof Slope

Mansard roofs with nearly vertical faces can boast a pitch of 20 in 12.

12 asphalt shingle roof slope.

18 43 asphalt shingles with special underlayment requirements 2 in 12. The 45 degree roofs seen on a frame houses are 12 in 12 but roofs can be even steeper consider the mansard roofs introduced by french second empire architects in the middle of the 1800s. This number corresponds to the number of inches of rise in a 12 foot run. 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. In 12 0 25 in 12 1 19 built up roof coal tar pitch. High and low pitch examples two examples at each end of the spectrum. Next multiply the footprint of the roof by the multiplier below for your roof pitch to find the overall roof area.

Minimum required roof slope for roofing materials. Asphalt shingles can only be installed on roof slopes of 2 12 or greater. This means for every 12 horizontal units the roof must rise a minimum of 2 vertical units. For most home styles roof pitches fall in a range 4 12 a moderate slope up to 8 12 fairly steep.

Pitched roofs begin with with slopes greater than 3 in 12. Asphalt shingle options a pitch of 2 12 is the minimum pitch for shingles made of asphalt so your roof just barely makes the cut off for one of the most popular roofing material options. Roof pitch area multipliers. Some people recommend not installing asphalt shingles on slopes below 5 12 but a skilled roofer may well be able to make this work.

Minimum required slope x in 12 minimum required slope degrees 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. 100 1 054 105 4ft 2. Use our roof pitch calculator to find the pitch of your roof.

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. Examples of extreme slopes range from 1 4 12 almost flat to 12 12 sloping down at a perfect 45 degree angle. Roofing material or system. The short simple answer is 2 12 has traditionally been considered the absolute minimum acceptable roof slope suitable for asphalt shingles.

Resilient asphalt shingles lie much flatter to the substrate than slate tile and concrete which keeps water from being easily blown under them. For example a 4 12 pitch roof that is 100 square feet.