Maximum Roof Slope Allowed For Ashphalt Shingle Roofing

Asphalt shingles continue to be the most widely installed roof covering option in north america.

Maximum roof slope allowed for ashphalt shingle roofing.

If 4 12 and above is normal and 2 12 is minimum what about properties with roofs in between the two such as a 3 12 pitched roof. Nrca s recommended minimum roof slope guidelines for steep slope roof systems generally are greater at steeper inclines than those in the building code. Run in degrees and as percentage the minimum roof slope allowed by code for any type of roof is in 12 applicable only to coal tar pitch roof systems. With respect to shingle application roof slopes from 2 12 to less than 4 12 18 5 are called low slope roofs while roof slopes of 4 12 or greater are called normal or standard slopes.

You are required to have a double layer of asphalt saturated felt paper or a single layer of ice water shield under your. This means for every 12 horizontal units the roof must rise a minimum of 2 vertical units. The slope of the roof is measured by the vertical rise of the roof to the horizontal run and is expressed as a fraction. Examples of extreme slopes range from 1 4 12 almost flat to 12 12 sloping down at a perfect 45 degree angle.

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. There are differing opinions as to the minimum slope for a roof but the generally accepted minimum is 3 12. Degrees to pitch rise in run table. Low sloped roof shingle installation.

Complete list of roofing types. We do install shingles on these in between pitches but special application measures must be taken in this middle ground. 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. What is roof slope and does it limit the choice of shingles.

This number corresponds to the number of inches of rise in a 12 foot run. Roof pitch multiplier table. Some people recommend not installing asphalt shingles on slopes below 5 12 but a skilled roofer may well be able to make this work. A 4 12 roof slope means the roof rises 4 feet.

Roof slope equivalents as rise. Minimum roof slope roof pitch r905 2 2. For every 12 horizontal feet the roof changes 8 feet in vertical height. The asphalt shingle roof contractors provide pitch estimator cards to measure the roof slope.

Asphalt shingles can only be installed on roof slopes of 2 12 or greater. For asphalt shingle clay and concrete tile metal shingle slate and wood shake and shingle roof systems nrca recommends slopes of 4 12 or more. High and low pitch examples. You can measure the roof slope either using tape or smartphone applications.

Asphalt shingles can only be used on roof slopes of two units vertical in 12 units horizontal 2 12 or greater. Normal shingle installation is allowed for all roofs with a pitch of 4 12 and above.