Ground Snow Load To Roof Snow Load Conversion

Other considerations for sloped roofs can be found throughout chapter 7 of asce 7 10.

Ground snow load to roof snow load conversion.

Ground snow load s s. Asce 7 drift height calculation. From eave to ridge w. Specifically examined are the effects on structural reliability of the change in the basic ground load to roof load conversion factor from 0 8 to 0 7 and recent statistical data concerning the conversion factor.

Horizontal distance from eave to ridge. Importance factor i s. Figure 7 1 pages 84 85 and table 7 1 page 92. The ansi snow load subcommittee took advantage of this new information to update and improve calculation of roof snow loads.

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. 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. 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.

Our recommendations on ground to roof conversion factors incorporates what we consider to be the most accurate information on the topic. Length of low roof ll. Version 0 1 0 september 25 2020. Length of roof downwind of the snow drift.

Length of roof upwind of the snow drift. Nsf 8 9 have shed new light on the ground to roof conversion factor. Medeek design assumes no liability or loss for any designs presented and does not guarantee fitness for use. 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 and the applicable snow. The snow load calculations provided by this online tool are for educational and illustrative purposes only. Length of high roof lu. If your roof is 1 000 square feet the total snow load is 15 000 pounds of snow.

Ground snow load pg. 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. In other words on a steep roof less material would be stacked in a concentrated area at one time to avoid having it slide off. Snow load factors are critically examined for use in load and resistance factor design lrfd.

Even when the specification is clear regarding ground snow vs. Roof snow load nbc 2010 roof snow load nbc 2010 version 0 1 0 september 25 2020. 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.