Roof Snow Load Tables

For roof live loads of 12 psf or 16 psf table multiply tabulated multiply required number span by e value by.

Roof snow load tables.

P s c s p f the thermal factor c t from table e 3 determines if a roof is cold or warm slippery surface values shall be used only where the roof s surface is unobstructed and sufficient space is. For roof live loads less than 20 pounds per square foot psf rafter spans and required e values tabulated for 20 psf shall be permitted to be adjusted in accordance with the fol lowing table. Lengthand widthof your roof. Depending on your region you may need to design for a maximum snow load of anything between zero to 65 pounds per square foot or roughly 0 3 kpa.

You need to supply the following information. Roof rafter span use this table to determine the maximum lengths of roof rafters based on species and grade of lumber spacing dimensions load and slope. Framing table for maximum roof rafter spans. The loads are based on adjusted roof snow loads from the governing building code.

The shapes and spans shown here represent only a fraction of the millions of designs produced by alpine engineers. Rafter span tables use these tables to determine lengths sizes and spacing of rafters based on a variety of factors such as species load grade spacing and pitch. To calculate the weight of snow on a roof use the first two sections of our snow load calculator. 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.

Total load psf duration factor live load psf roof type 55 1 15 40 snow shingle 55 1 15 30 snow tile 47 30 snow 40 20 snow 1 25 20 construction or rain not snow load 55 1 15 40 snow. Flat roof snow loads p f the snow load that is applied to our structure is not the ground snow load but in most cases the flat roof snow load. You can enter these values in any units you d like including meters and feet. The actual design roof snow load is determined from the ground snow load sg provided in table 1 using a number of factors discussed in the ubc code and the asce 7 95.

Use this table to determine the maximum lengths of floor joists based on species of lumber joist spacing and joist size. These factors include the effects of i terrain ii exposure iii thermal condition iv importance factor and v roof slope. Let s look at the sample table below which shows maximum rafter spans for a snow load of 31 3 pounds per square foot psf. Span configuration and load conditions.