Roof Snow Load Support

Wind exposure of roof.

Roof snow load support.

P s c s p f where. 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. The truss could be designed based on the assumption that the 25 psf roof snow load is a factored ground snow load in which case a ground snow load is back calculated using asce 7 based on the specified roof snow load pg 25 psf therein lies the problem with specifying only a roof snow load. For ground snow loads greater than 20 pounds per square foot the roof load is equal to 70 of the product of the exposure thermal and importance factors the ground snow load and 20 pounds.

It is determined based. P s c s p f 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. Snow can occur in many different load distributions on the roof. The asce 7 16 standard requires both balanced and unbalanced snow load case scenarios for a structure s design consideration.

Roof snow load is defined as the weight of snow on the roof surface used in design of the building structure ibc 2012. While both do well to support the weight of snow asphalt shingles are a more affordable option and easier to replace if necessary. Roof slope factor c s the roof slope factor is dependent on various roof properties including temperature shape and material. The sloped roof snow load is calculated using equation 7 4 1.

If you want to calculate these values by hand use the following formulas. The load placed on a particular roof is influenced by the design of the building and other environmental factors. On multiple factors including. Amongst others the snow load depends on the shape of the roof the insulating properties the surface roughness the heat build up under the roof the neighboring buildings the surrounding area and of course the local climate.

C s roof slope factor p f flat roof snow load. For roofs that are flat and with ground snow loads lower than 20 pounds per square foot the roof snow load is equal to 70 of the product of the exposure thermal and importance factors and the ground snow load. While this may be more intuitive for flat or even gable hip type roofs the determination of snow loads is increasingly more difficult for arch roofs due to complex geometry. The determination of the drift load that is.

You can also find the load per square meter or square foot of roofing by opening the advanced mode. Sloped roofs especially steeply sloped roofs such as the a frame styles common in very snowy climates shed snow very efficiently and carry a much lower load than flat roofed structures. Ground snow load value. Importance occupancy and use of the building.

Choose a strong durable set of shingles like asphalt or slate. Once you know these values our snow load calculator automatically finds the total weight of snow on your roof.