Hey guys,
I am going to be building a rather simple 18’x24′ addition to my house. I am planning to use a 4:12 mono pitch roof. I have attached a few pictures with some rough plans. I got a quote today to use I-joists as the roof rafters and the engineer suggested 14″ tall 24′ (2 feet overhang on each side) I-joists. They quoted me at $250 a piece. Looking at the IRC codes, a #2 2×12 dimensional lumber could span 25’9″ 16″ O.C. for roof rafters
I am wondering if I could use the 2×12 dimensional lumber or if I am better off using the -I-joists. I am in upstate New York so I am not sure if the span charts are different due to snow loads and what not.
Any help you have will be much appreciated
Replies
Go back and ask your engineer.
There are other rafter tables in the IRC for snow loads, but you are far enough north you might want to have local input. (Upstate NY includes a wide range of expected snowfall)
The tables also depend greatly on the actual species and grade.