Another Lean-To Question

[jrwhitey_2000]

Good Evening,

I have a 32x56x12 metal sided and roofed pole barn. I would like to add a lean to to the back of the eve wall. I want to be able to reuse the tin from the back wall of the current building and use it on the lean to addition so I will cut the tin off enough to expose just enough to add a toe board to run my rafters. Current roof is 4/12. I wanna retain as much height as possible and get as much width as I can. Would like the low end of the lean to to have 8’ clearance. I am located in Ohio. Suggestions on how much span I can get and what size rafter and spacing. I will either build or buy laminated posts and use a double 2x12 header on the out wall of the lean to. Will likely notch the rafters to set on the existing building header and also secure to the header with metal joist hangers


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[Copymutt]

Re: Another Lean To Question

It depends on what pitch. Don't know if your in snow country where shedding load is important. Let's draw a triangle to scale. Start with the 12' height common wall.
Play with your pitch line to intersect a parallel line to the 12' at the 8' outer wall. Then connect a rt. angle line from the top of the 8' line to the 12'. That is your span or floor width. You'll see it varies with pitch. The 8' needs to be adjusted for rafter width to get a true 8' of headroom.
Again your rafter spacing depends on snow load. County bldg. Dept. can provide this for your area. Most likely you'll be less than us at 80# per sq.' and in the realm of 2x10s no more than 24" O.C. Or you could make trusses out of 2x6s if your wanting to close in a portion for a 8' ceiling, easier to insulate and heat
Jim