I’d like to build a carport. It will basically just be a shed roof extending off the front of my garage. I’ll need a beam, as thin as possible, to span 22 feet from side to side.
It looks to me like steel is the only thing that could easily do that, but the cost is high, and how thick does it have to be? I priced out some 6" i-beams. $500 each. How do I attach wood to those? Can’t exactly nail into them.
That brings me to LVLs and such. Less pricey, but very thick. I suppose I could double up on a couple of thinner ones (like 6") but they don’t seem to be rated for exterior use, and I’m pretty sure a carport would be considered exterior use, even though they’d be under a roof.
Any guidance?
One option would be to make the beam a flush condition. To get a 16’ span with rafters you’re going to be using at least 2x8s. That’s 7.25" deep. If you were set the top of the beam at the top of the rafters and hang them from the beam (simpson or USP hangers) that buys you some space. Now an 11.88" LVL would only stick down 5-5/8" below the bottom of the rafters. (okay, 5-3/4"-6" with the additional slope over the 5.25" of beam) I’m not saying that a 3 ply 11x88 LVL with a 2.1E, bearing in a BC6 cap on 6x6s would work for your application, but the height tolerance would seem to add up in your favor.