Ground Snow To Roof Sno

Snow loads acting on a sloping surface shall be assumed to act on the horizontal projection of that surface.

Ground snow to roof sno. 1995 ground snow load table. 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. Ground snow load values for ontario and quebec. 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.

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. Ground snow load p g. 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. 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.

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. 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. 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. P s c s p f.

Posted at december 21 2014 in technical. 0 7 x ce x ct x is x pg pf. 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. For example fresh snow is soft fluffy and light.

Psf 5 psf 300 psf roof pitch. 2005 ground snow load tables. Return to top. 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.

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. Site designed and maintained by york digital solutions inc. Thermal factor c t. 2010 ground snow load table for ontario.

If your roof is 1 000 square feet the total snow load is 15 000 pounds of snow. The density of snow and hence its load per square foot depends on the type of snow. Pg is converted to pf by this formula. Roof and building data.

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. Required data design assumptions.