The dead load of a typical asphalt shingled wood framed roof is about 15 pounds per square foot.
Roof load psf.
Each square foot of the surface has the same load.
Roof loads are a downward vertical force on the home.
The following table provides typical weights dead load self weight for various roofing materials where possible the values were taken directly from manufacturer technical data sheets and are the actual weights of specific representative products.
Location 2uniform load psf kn m roofs ordinary flat pitched and curved roofs roofs used for roof gardens roofs used for assembly occupancies roofs used for other occupancies awnings and canopies fabric construction supported by a skeleton structure screen enclosure support frame.
The density of snow and hence its load per square foot depends on the type of snow.
The north zone middle zone and the south zone are identified on the roof load zone map above.
On the other hand snow that stayed on your roof for a few days will settle and while it seems that the cover gets thinner its weight doesn t change it s just the density that is different.
Roof load live load design is affected by the shape of the roof whether it is flat curved or pitched.
The minimum design roof snow load after allowed reductions shall be 30 psf.
The load increases with the use of heavier roofing material.
For example fresh snow is soft fluffy and light.
Remember these loads are distributed uniformly over the entire surface of the roof.
Here each square foot of roof system delivers 50 pounds of live load and 15 pounds of dead load 65 psf total to the structural support system.
B psf pounds per square foot is used to describe loads on flat surfaces such as floors and roofs.
In areas of the state outside of certified local government jurisdictions the design snow load shall be based on the ground snow loads developed in snow loads for structural design in montana authored by f f.
Schilke civil agricultural engineering montana state university august 1989.
A clay tiled roof may have a dead load.
To total the load on an area multiply the area times the psf.
This downward imposed load on the home is also known as the snow load.