Ground Snow To Roof Sno

Typically the leeward drift height hdl is greater than the windward drift height hdw unless the length of the lower roof is considerably longer than the length of the upper roof.

Ground snow to roof sno.

P s c s p f. The determination of the drift load that is required for unbalanced snow load cases requires the use of the ground snow load pg not the roof snow load. 2005 ground snow load tables. The sloped roof snow load p s shall be obtained by multiplying the flat roof snow load p f by the roof slope factor c s.

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. 2010 ground snow load table for ontario. 1995 ground snow load table. The amount of additional snow load or surcharge depends on the difference in height of the two adjacent roofs and the lengths of roof perpendicular to the drop in height.

The density of snow and hence its load per square foot depends on the type of snow. Snow loads acting on a sloping surface shall be assumed to act on the horizontal projection of that surface. Snow can either blown from the low side of the roof towards the high side or is blown off the higher area of the roof onto the lower projected side. Pf is flat roof snow load if as a consumer your concern is snowfall and you want to upgrade the ability of your building to carry it this is the value to increase.

2010 ground snow load table for quebec. In other words on a steep roof less material would be stacked in a concentrated area at one time to avoid having it slide off. 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. Posted at december 21 2014 in technical.

For example fresh snow is soft fluffy and light. Thermal factor c t. If the ground snow load isn t specified then a ground snow load needs to be assumed and the truss designer and the building designer may not be on the same page as it relates to this design assumption. In my region on cape cod we have a ground snow load design of 25 psf which is a greater design load than the live load 12 psf to 20 psf over an entire roof system.

Return to top. Psf 5 psf 300 psf roof pitch. Site designed and maintained by york digital solutions inc. Leeward drift results from snow blown off a high roof onto a lower roof.

Pg is converted to pf by this formula. 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. Often changes of five or 10 pounds per square foot result in minimal differences in cost. 0 7 x ce x ct x is x pg pf.

Ground snow load values for ontario and quebec. Ground snow load p g.