Shed dormers are easier to waterproof and shed snow better than gable dormers.
Snow load design for roof overhang.
In areas prone to excessive snow accumulation like schweitzer and similar.
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.
The snow load calculations provided by this online tool are for educational and illustrative purposes only.
This includes overhangs and multiple roof levels.
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.
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.
P s c s p f.
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.
R802 10 2 and designed according to the minimum requirements of asce 7 10.
Snow loads acting on a sloping surface shall be assumed to act on the horizontal projection of that surface.
In some cases roof snow melt systems or heat tape can be used to combat ice accumulation on eaves and in valleys.
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.
For the design of an actual structure a registered and licensed professional should be consulted as per irc 2012 sec.
The balanced snow load is applied everywhere where the roof structure is located.
Partial unbalanced and drift loading.
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.
The ground snow load map shown below was scanned from the asce 7 10 figure 7 1.
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.
Shed dormers should be considered if the design and style of the home allow.
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.
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.
