Ground Vs Roof Snow Oad

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.

Ground vs roof snow oad. Pf is flat roof snow load if as a consumer your concern is snowfall and you want to upgrade the ability of your building to carry it this is the value to increase. In my region on cape cod we have a ground snow load design of 25 psf which is a greater design load than the live load 12 psf to 20 psf over an entire roof system. Sheikh taheri through years of research. Other considerations for sloped roofs can be found throughout chapter 7 of asce 7 10.

If the ground snow load isn t specified then a ground snow load needs to be assumed and the truss designer and the building designer may not be on the same page as it relates to this design assumption. Each state has a listing of building code and applicable guidelines for snow loads as well as details about where the snow load information may be found or purchased. 49 42 35 28 24 5 21 17 5 assumed value thermal factor ct. The bottom line is that the irc requires you to design the roof structure to the greater roof load and in my region that s the ground snow load.

Length of roof upwind of the snow drift. Length of high roof lu. Ground snow load or roof snow load snow load. 1 0 importance factor i.

It was released in 1986 by the department of civil engineering at the university of idaho. 70 60 50 40 35 30 25 x0 7 x0 7 x0 7 x0 7 x0 7 x0 7 x0 7 roof snow load. From eave to ridge w. Horizontal distance from eave to ridge.

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. 1 0 exposure factor ce. The determination of the drift load that is required for unbalanced snow load cases requires the use of the ground snow load pg not the roof snow load. In our case let s assume that our structure has a flat roof roof slope 5.

The snow load that is applied to our structure is not the ground snow load but in most cases the flat roof snow load. If your roof is 1 000 square feet the total snow load is 15 000 pounds of snow. Weight of permanent. Snow loads can be presented in two different ways.

Figure 7 1 pages 84 85 and table 7 1 page 92. When discussing snow load with anyone it is crucial to have a clear understanding as to if the load is a ground or flat roof snow load. Length of roof downwind of the snow drift. 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 flat roof snow load is calculated using formula 7 3 1. Purpose of this web site. Ground and roof snow loads for idaho 1986 this report was compiled by ron sack and a.