Snow Load Design For Roof Overhang

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 load design for roof overhang.

Shed dormers are easier to waterproof and shed snow better than gable dormers. This includes overhangs and multiple roof levels. R802 10 2 and designed according to the minimum requirements of asce 7 10. In areas prone to excessive snow accumulation like schweitzer and similar.

The process involves one simple equation and some knowledge of the loads that the beam will carry. 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. P s c s p f. The balanced snow load is applied everywhere where the roof structure is located.

Sloped roof snow loads calculations and regional design. The ground snow load map shown below was scanned from the asce 7 10 figure 7 1. 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. Shed dormers should be considered if the design and style of the home allow.

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

Sliding load on adjacent roof ponding faq s 3 minimum roof snow load clarification scenario roof load right after heavy snow w o wind no time for thermal no wind roof load p r p g 4 minimum roof snow load p m i s p g p g 20 psf p m 20 i s p g 20 psf the 20 psf value is our estimate of the maximum size of a single heavy snow. 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. For the design of an actual structure a registered and licensed professional should be consulted as per irc 2012 sec. 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.

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.