IBC Snow load factors

[I-beam]

I am designing a small (30'x40') storage shed for construction vehicles, completely open on 1-side.
Do I have to use a thermal factor of 1.2 for snow load for an unheated roof with a occupancy category 1, I = 0.8.
This is used strictly for parking equipment, no service work / etc.

 

[TehMightyEngineer]

Yes.

Ian Riley, PE, SE
Professional Engineer (ME, NH, VT, CT, MA, FL, CO) Structural Engineer (IL, HI)

 

[JAE]

....because humans still will be occasionally inside the building despite the low risk category.

 

[campbelltc]

Just one man's opinion: For the slight increase in design load, I'd use the Is = 1.0. If anything would happen, I wouldn't want to try to defend a few dollars for the cost of replacement or, God forbid, a person's life.

We design primarily in a 30 psf ground snow area. We use 30 psf minimum for new construction, even though we could usually factor it to 21 or 23 psf. Too many local roof collapses in uncommon snow events (not any of ours, but just seeing them) during my career to take the chance.

And yes, use the Ct = 1.2.