Snow Pressure On Roof

4 2 lateral snow pressure.

Snow pressure on roof.

If your roof is 1 000 square feet the total snow load is 15 000 pounds of snow. View of the upper roof adjacent to the skylights after removal of the drift. The key purpose of a snow retention system is to hold and retain snow ice on the roof and allow a controlled evacuation of the snow which will help protect your assets and decrease your liability. Roof snow loads for idaho universityotldaho department of civil engineering moscow idaho 83843 r.

10 12 inches of new snow is equal to about one inch of water or about 5 pounds per square foot of roof space so you could have up to 4 ft. Structural damage ice dams causing roof rot damage to flashing and gutters etc collapse. For locations where 0 pg 20 psf all roofs with a slope w 50 with w in ft shall have a 5 psf rain on snow surcharge. Note the shovel marks on the snow indicating that some snow was deliberately left over the roof membrane.

A properly designed and installed system will retain the snow on the roof and prevent damage to gutters signage lighting landscaping canopies. The online calculator takes type of snow into account instead of exact weight to determine snow load. The red arrow indicates the lower roof in the area of the deflected skylights. If your roof is located in windswept areas or even north of the treeline the wind will cause snow drifting making less of it accumulate on your roof.

Slipperiness of the roof. Thus snow weighing 10 pounds per cubic foot and at a depth of 18 inches on a roof is exerting 15 pounds of pressure per square foot. View of another area where drifts were removed. Of new snow before the roof will become stressed.

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. Less snow will accumulate on a slippery roof it will slide off instead. 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. Roofs under pressure from too much heavy snow are at risk of.