Ground snow load s s.
Montana ground snow load to roof converter.
Importance factor i s.
The snow load that is applied to our structure is not the ground snow load but in most cases the flat roof snow load.
Pursuant to montana law the minimum design roof snow load after allowed reductions shall be 30 psf.
S i s s s c b c w c s c a s r.
If your roof is 1 000 square feet the total snow load is 15 000 pounds of snow.
Rain load s r.
R802 10 2 and designed according to the minimum requirements of asce 7 10.
Or the 25 psf snow load could be entered as a roof snow load with the unbalanced snow loading option turned off.
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.
Roof snow load nbc 2010 version 0 1 0 september 13 2020.
Local codes and ammendments may govern verify with local building department or jurisdiction.
Local and or state requirements on the ground snow loads or the roof loads subsequently calculated from these values supercede the values provided by this snow load finder tool.
In our case let s assume that our structure has a flat roof roof slope 5.
Snow loads shall be determined by the building official.
Specified snow load.
For the design of an actual structure a registered and licensed professional should be consulted as per irc 2012 sec.
Ground snow loads derived from montana ground snow load finder.
The flat roof snow load is calculated using formula 7 3 1.
Note that the state of montana requires a minimum roof snow load of 30 psf to be used for design regardless of ground snow load.
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 state of montana requires a minimum roof snow load of 30 psf be used for design 2 this minimum value applies to the final roof snow load that is calculated after all coefficients have been applied and it may be revised when justified by a design professional to the satisfaction of the building official.
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.
Note that the state of montana requires a minimum roof snow load of 30 psf be used for design.