Residential Roof Snow Loads

For example fresh snow is soft fluffy and light.

Residential roof snow loads.

Overestimation of snow loads can unnecessarily increase the cost of construction. A great deal of confusion currently exists among engineers architects recreation specialists and maintenance personnel concerning the proper snow loading to use for the design and maintenance of trail bridges building roofs and other structures in mountainous high snow load areas. Snow loads are influenced by elevation general weather and moisture patterns slope direction exposure roof or trail bridge configuration and wind direction and severity. If the snow weighs 10 pounds per cubic foot and there are 1 5 feet on the roof each square foot of the roof is getting 15 pounds of pressure.

If your roof is 1 000 square feet the total snow load is 15 000 pounds of snow. Simple design check representative of worst case combined axial and transverse loading. The 20 psf load is equivalent to 14 inches of snow at the design density while the 25 psf load is 17 inches. Axial forces from snow loads and roof live loads should usually not be considered simultaneously with an extreme wind load because they are mutually exclusive on residential sloped roofs.

To figure out the load on your roof take the depth of snow in feet and multiply it by the weight of a cubic foot of snow. Snow loads roof snow loads are influenced by elevation general weather and moisture patterns slope direction exposure roof configuration and wind direction and severity. On the other hand snow that stayed on your roof for a few days will settle and while it seems that the cover gets thinner its weight doesn t change it s just the density that is different.