Minimum Roof Angle For Shingles

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 roof angle for shingles.

Determine the minimum slope of the roof based on the roofing material. Use a handy tool like snow load calculator to help you determine if your roof can handle the weight of snow based on its pitch. The angle of a 2 12 pitch roof is roughly 9 46 degrees rounded to 9 5 in most cases. Mineral surfaced roll roofing minimum roof slope roof pitch r905 5 2.

These are also the most common pitches for shed roofs. The standard for roof pitch is 4 12 though a 2 12 is completely fine for most structures. Again the most important consideration is the weather. The short simple answer is 2 12 has traditionally been considered the absolute minimum acceptable roof slope suitable for asphalt shingles.

This means for every 12 horizontal units the roof must rise a minimum of 3 vertical units. That works out to about nine degrees if that works better for you. The 2 12 number is rise over run or two units of vertical for every 12 units horizontal. What is the minimum slope for an asphalt shingle roof.

The requirements for an asphalt shingles roof are contained in the international building code. Asphalt shingles continue to be the most widely installed roof covering option in north america. How roof pitch determines suitable roofing systems. Flat and nearly flat roofs a pitch of 1 in 12 or 2 in 12 cannot be covered with shingles or shakes of any material since there is not enough angle to combat the danger of blow off.

Metal roof shingles can only be installed on roof slopes of 3 12 or greater 25 slope. The highest degree possible is a 45 degree roof which is a 12 12 pitch roof. The minimum pitch for shingles is 1 6 which is equivalent to 4 inches rise to 24 inches run. Any roof from 4 12 to 9 12 is considered an ordinary angle for a roof.

Shingles of all types need to have a slope to function properly. The following table provides the minimum required allowable roof slope for each type of roofing material mentioned in the code. A shingle roof like this north dallas garage in the photo above may have a failure no matter how good a job the installer did. For simplicity sake every degree of pitch is roughly 4 75 degrees.

Metal roof shingles minimum roof slope roof pitch r905 4 2. The minimum requirement is 2 12.