Snow Load Design For Roof Overhang

The process involves one simple equation and some knowledge of the loads that the beam will carry.

Snow load design for roof overhang. Our sample homes are in an area where the snow load is 50 pounds per square foot of roof area treat snow as live load. For a porch roof the beam needs to be sized according to the maximum snow loads in your area and you must know enough about the porch design to determine how the load will be distributed and over what distance the beam will carry the load. R802 10 2 and designed according to the minimum requirements of asce 7 10. When snow slides off a sloped roof onto a lower roof the design snow load on the lower roof due to sliding snow is determined using section 7 9.

Partial unbalanced and drift loading. It goes without saying that in a warmer climate the snow load probably would be less so you need to check your code book for live loads and dead loads in your region. In some cases roof snow melt systems or heat tape can be used to combat ice accumulation on eaves and in valleys. Snow loads acting on a sloping surface shall be assumed to act on the horizontal projection of that surface.

If you live in the us our snow load calculator compares the total weight on your roof with the permissible load calculated according to the standards issued by the american society of civil engineers regarding the minimum design loads for buildings and other structures asce7 16. 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. This includes overhangs and multiple roof levels. After you obtain the roof slope factor from those sections in asce 7 10 the balanced design snow load for the sloped roof can easily be calculated using equation 7 4 1.

Roof snow loads are based on the historical records for ground snow loads for a given location however the local building authority should always be consulted to determine the correct roof snow load to use for a given site and application. According to this section sliding loads shall be superimposed on the balanced snow load and need not be used in combination with drift unbalanced partial or rain on snow loads roof overhangs. In areas prone to excessive snow accumulation like schweitzer and similar. The snow load calculations provided by this online tool are for educational and illustrative purposes only.

For the design of an actual structure a registered and licensed professional should be consulted as per irc 2012 sec. The ground snow load map shown below was scanned from the asce 7 10 figure 7 1. Sloped roof snow loads calculations and regional design. P s c s p f.

Shed dormers are easier to waterproof and shed snow better than gable dormers.