Roof slopes lower than 4 12 tend to perform well with metal roofs which are less prone to leakage and ice dam formation.
Suggested snow roof degree.
The pitch of the roof is determined by the vertical rise.
A 30 degree roof slope 7 12 pitch is the right pitch to aerodynamically handle high wind.
If you live in the us our snow load calculator compares the total weight on your roof with the permissible load calculated according to the standards issued by the american society of civil engineers regarding the minimum design loads for buildings and other structures asce7 16.
The 30 degree 7 12 roof recommendation is backed up by testing according to the publication science daily.
S equals the depth in inches of the snow on your roof and p represents the pounds per square foot your roof is supporting.
Lower slopes don t handle wind driven rain as well.
According to this code the minimum slope for asphalt shingles is 17 degrees or two vertical units to twelve units in the horizontal.
At these slopes snow creeps rather than slides and is easy to manage.
Slate is also a popular material in this climate zone.
In snowy areas your roof should be at least 10 12 40 to allow snow to shed while the safest roof pitch in very windy areas is between 4 12 6 12 18 5 26 5.
On roof slopes between 4 12 and 6 12 rough textured roofing materials work best.
A reputable roofing contractor will be familiar with the pitch required by these codes.
Pitch is a measure of the steepness of a roof.
Building a roof with wood shakes works well in moist colder climates as they don t dry out from the snow.
The requirements for an asphalt shingles roof are contained in the international building code.
There are some opinions that standing seam metal roof minimum slope is 12 but it increases the possibility of leaking on the few first days of snow arrival.
Your equation for determining snow load s x 1 25 p is fairly straightforward math.
In country with heavy snow and tough winter days the metal roof minimum slope is recommended to be 1 12.
Determining the roof pitch for your weather the first thing to do is to check the building codes for your county and state.