Minimum Roof Pitch For Snow Loads

Sloped roof snow loads are assumed to be acting on the horizontal projection of the surface.

Minimum roof pitch for snow loads.

You can safely measure the roof pitch from inside your attic with a level that is either 18 or 24 inches a tape measure and a pencil. When the roof slope is greater than 5 the roof is considered sloped. The minimum roof slope allowed by code for any type of roof is in 12 applicable only to coal tar pitch roof systems. If you are adding an addition to your home or installing skylights knowing the existing pitch is important.

The sloped roof snow load is calculated using equation 7 4 1. P s c s p f. The key factors are usually snow loading requirements adequate slope and the use of snow guards when needed. Begin by measuring 12 inches on your level and marking it with a pencil.

All commercial buildings and structures should use the ground snow load values from the 2009 ibc and not the residential design values given below. Roof design snow loads derived from figure 321 02 of the wisconsin. The following table provides the minimum required allowable roof slope for each type of roofing material mentioned in the code. 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.