Snow Pressure On Roof

4 2 lateral snow pressure.

Snow pressure on roof.

Note the shovel marks on the snow indicating that some snow was deliberately left over the roof membrane. Structural damage ice dams causing roof rot damage to flashing and gutters etc collapse. The online calculator takes type of snow into account instead of exact weight to determine snow load. If your roof is 1 000 square feet the total snow load is 15 000 pounds of snow.

Less snow will accumulate on a slippery roof it will slide off instead. View of another area where drifts were removed. 3 roof maintenance. Of new snow before the roof will become stressed.

Roof snow loads for idaho universityotldaho department of civil engineering moscow idaho 83843 r. 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. 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. 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. 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. 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 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.

The red arrow indicates the lower roof in the area of the deflected skylights. This rain on snow augmented design load applies only to the balanced load case and need not be used in combination with drift sliding unbalanced or partial loads. View of the upper roof adjacent to the skylights after removal of the drift. Slipperiness of the roof.