Proper Roof Pitch For Snow

Divide the results by the number of 12 inch segments in your level.

Proper roof pitch for snow.

Pitch is a measure of the steepness of a roof. So in general the shallower pitch can be more dangerous with bigger slides. Any pitch higher than 9 12 is considered a steep pitch. Have a real chance to soak in and find the weak spots.

In areas with high rain and snow fall roof pitches traditionally tended to be relatively steep to encourage water and snow to drain and slide off. The minimum pitch for a roof is 1 4 12 which translates to 1 4 inch rise to 12 inches of run. Begin by measuring 12 inches on your level and marking it with a pencil. 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.

If the design necessitates a roof slope that drains onto a traffic area snow retention devices should be provided to hold the snow in place. But since there is still a wide variety of slate roofing systems there are occasions when the minimum pitch can go down to as low as 15 0 depending on the uniqueness of the roof. Once in the attic hold your level against the bottom of a roof rafter ensuring that all bubbles are resting in the center. Whereas in dry areas roofs could be flatter.

The smallest pitch of a roof is 0 5 12. However you can only use this pitch with built up roofing or specialized synthetic roofing. 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. The higher the roof pitch the more often the snow slides off.

With regards to the pitch the building standard code bs 5534 recommends a minimum pitch of 200 for slate roofs. Roof pitch degree table. The pitch of the roof is determined by the vertical rise in inches for every horizontal twelve inch length. You can also estimate a roof pitch by eyeballing it from the ground from the gable side with a level and ruler.