Help!-need advise shed side roof construction-many pics
I need some help designing the shed side roof of this pole barn. I live in Northern Nevada but own 175 acres in Idaho. I had hoped to be up there long ago but the economy caught us off guard and now I am kind of stuck in Nevada, hoping my home value rises to the point where I can at least break even and not have to dump my home.
I tell you this because I started this pole barn right before things went bad and it was never finished. Making things worse I relied on help from a guy who needed my pasture for his cattle and we were trading pasture for labor. I and a few friends started the building with this cattle guy's help and the original building went up ok. That was five or so years ago. I had been trying to get him to pour my concrete for several years with no luck and excuses. This spring me and some buddies went up and did the main portion of the building in concrete but it was pretty early and a nightmare at best due to the weather. Now the cattle guy has done the small shed side concrete 16x30 and I have this side wall sitting up in the air on four posts with a header sitting on it.
I have now given up on the cattle guy who owes me over 6K, as this is just one project he was suppose to get done, (Fencing, a log entry way and more) have never been done.
I have attached a few pics of the building as I an curious on what you guys think. I need to get up there (8 hours away) and at least get the side wall tied to the main building before it sits in the snow all winter.
I am curious on how you think I should tie into the main building and what to use? Its a 90LB snow load and I want it done right so was planning on doing a 100lb snow load. What's not pictured in the pics is the concrete is now done on the shed side. I was planning on using 2x12s by 20s but am not sure how to tie in on each side or if I should build an interior wall on the barn side to tie into. Or if I should lag 2x12s into the posts and connect them atop of the header? and if so, then do I run purlins sideways between the 2x12s?
I attached a few pics of the original way the barn went up and a few of how the shed side wall sits now?
Any ideas. lumber company says 2x12s at 24 inches will do it, but how to attach it is another story. I don't really trust them either as they have sent me junk in the way of braces, ect in the past.
The building was originally going to be storage. Since I can no longer take 300K out of my current home and leave, this is going to be a shop. Its 30x40 and the shed side is 16x30. This MAY BE a place I have to live in for a while when and if I can ever build near the pond. I have a fifth wheel but this will have a bathroom, ect and I want it strong if you know what I mean. Im trying to do this out of pocket these days and cant afford some high dollar set of trusses, ect.
any help is GREATLY appreciated!!!
what is the wood species for the rafters?
as far as your rafters, here is an online calculator from the American Wood Council. Plug in the species of wood, the size of the member and spacing, select rafter and enter your snow loading and use the L/180 deflection limit and it will give you the maximum span http://www.awc.org/calculators/span/...rcalcstyle.asp
I'm not sure I buy the 2x12 at 24" o.c. for a 90 psf snow load (live load) and 10 psf dead load. You have to remember snow on the upper roof will slide off impacting the lower roof, plus with a wall above the shed roof you'll get snow drift (snow hitting the wall and piling up on the roof) so you'll have greater load adjacent to the wall of the barn. You are subject to greater loading than the 90 psf ground snow load in my opinion. You can build it as your describe and it will work, how long I can't say. I think you'd be better at 16" o.c., even better at 12" o.c. If your shed roof had something like a 10:12 or 12:12 pitch roof I might not be as concerned as the snow would slide off easier. I'd say you'll be looking at something like a 4:12 or 6:12 for your shed.
As far as attachment I see two ways of doing so. first is install a beam between the columns of the barn that will carry 1/2 the weight of the shed roof, or two build a 2x wall in between the columns and attach a ledger to it. The ledger would be secured to each stud in the wall with a couple of lag screws. It appears you have approximately an 8-foot span between the columns so you'd need something like a 3 ply 2x12 beam (see if your lumber yard can calculate it for you) if you went that route. you can through bolt the beam to the columns, but would need to add a 2x (width of column) to the exterior face of the column under the beam to support the beam load to follow prescriptive code, or could hire a professional engineer to design the bolt connection.
Whether you use a beam or a ledger use metal connectors to attach the rafters to the beam/ledger. Also use hurricane ties to attach the rafters to your header. Toe nails work great at resisting lateral and shear load (side to side and front to back) but do nothing for uplift.
Hope this helps. Good luck!
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