Minimum Flat Roof Snow Loads

[SteelPE]

I am working on a building with a jurisdiction that has a minimum flat roof snow load. The code gives a notes saying the following:

"The design flat roof snow load shall be the larger of the calculated flat roof snow load using Pg or the value of Pf listed in this table.

In this instance the ground snow load is 50 psf and the minimum flat roof snow load is 35 psf.

This structure is a greenhouse and the I can see the manufacturer trying to make an argument to use Is=0.8 and Ct=0.85 to bring the snow load down to 23.8 psf, but from the way I interpret the code, the minimum load to be used on the roof should be the 35 psf specified regardless of any reductions the code may allow for temperature or occupancy. How would you treat a greenhouse structure in reference thermal/importance factors and minimum flat roof snow load a specified by the code?

 

[BAretired]

If the roof is flat, I agree, but if the roof is sloping, you may be able to consider a value less than 35 psf on the basis of slope factors applied to the 50 psf ground snow.

BA

 

[phamENG]

I agree with BA. If p_f=23.8psf based on ASCE 7 calculations, then use p_f=35psf. If the roof is flat, that's your load. If it's sloping, p_s=C_s*35psf.