Snow Load On Sloped Roof

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.

Snow load on sloped roof.

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

It makes sense when designing a metal roof to shed snow not to keep it on. It is critical that a designer specify enough snow retention devices based on the slope and snow load. Snow loads are influenced by elevation general weather and moisture patterns slope direction exposure roof or trail bridge configuration and wind direction and severity. Roof snow load is defined as the weight of snow on the roof surface used in design of the building structure ibc 2012.

With expansion and contraction of the metal it is difficult to attach snow retention devices into the roof decking without causing a roof leak or slotting of the metal panel from the snow bracket fastener. 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. If your roof is 1 000 square feet the total snow load is 15 000 pounds of snow. Boca also allows you to reduce the snow load for roofs with slopes greater than 30 degrees presumably because snow will slide or blow off steeply pitched roofs.

The snow load that is applied to our structure is not the ground snow load but in most. Sloped roof snow. P s c s p f. However in my practice i typically use the horizontal run of the roof for both types of load.

Once you know these values our snow load calculator automatically finds the total weight of snow on your roof. To do this i use conservative too heavy dead loads and full snow loads regardless of pitch. The thermal factor c t from table e 3 determines if a roof is cold or warm slippery surface values shall be used only where the roof s surface is unobstructed and sufficient space is available below. Calculating roof snow loads w asce 7 10 a walk through on how to calculate roof snow loads per asce 7 10.

For dead loads you are correct. Ground snow load value. Technically you should use the actual rafter length when adding up the weight of roofing materials. Snow load thickness density.

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. The effect of snow loads on a structure can have dire. Flat roof snow loads p f. Discount that actual snow loads may exceed them only that the risk of snow load induced failure is reduced to an acceptably low level.

If you want to calculate these values by hand use the following formulas.