Pole Barn Loft Framing

[jcook5003]

Hi Guys-

Since I'm almost finished building my run in shed and am planning my horse barn now I'm looking for photos or plans of pole barn lofts and how to frame them.

My barn is going to be 36x48 with typical 12' pole spacing. I was thinking about using scissor trusses to increase loft ceiling hieght. I was thinking of running a 2x12 band a few feet down my posts and running 2x10 floor joists parallel to the 36' wall. Is this how most people do it? will a single 2x12 be sufficient to support the floor load?

Anyone with pole barn loft framing photos or plans I would be thrilled to see them.

Thanks,
Josh

 

[rus_geek]

Lots of details to add before you figure out how to frame the loft. Will the loft span the entire building, or just X feet from one end? Do you want any support posts under the loft, or want to keep it clear spanned? How much weight are you putting in the loft?

-rus-

 

[jcook5003]

It will be a full loft the entire length of the building.

It wont be hay storage so minimal weight.

It will be supported by a 6x6 every 12'.

A contractor friend just told me basically putting a loft in a pole barn is simply building a deck. Simple as that. It made sense.

 

[bp fick]

Yes, basically, your friend is correct. Deck building is a good analogy. I am putting in lofts in my mini barn right now. However, unlike a deck, one has to compute the load and ask the question, what is carrying this load? You'd be amazed how many lofts/decks are actually only being held up with nails. There will be failure down the road. There are a number of ways to accomplish the task, based on your building specifics. Personally, I like to support the ends of the floor joists with either a minimum of 4"-6" of end support, (two 2 by or more width) and/or joist hangers. There are also charts for clear span capabilities of 2x8, 2x10, 2x12, etc.

 

[jcook5003]

I ALWAYS use hangers, brackets etc when building, I also religiously use notches in posts to help support boards. Coming from my engineering school side (sophmore year) I think what I have in mind lumber dimension wise whould be fine.

 

[Duffster]

In this application I wouldn't use trusses at all. Rafters will give you more head room in the loft.

 

[ray66v]

Have you not considered using attic trusses in the area where you want the loft?

 

[jcook5003]

Attic trusses were $4k more than scissor trusses. I would use rafters but trusses GREATLY simplify the building process and make it much fast IMHO.

 

[EddieWalker]

I'm not clear on what you want to do. With a 36 ft span, are you wanting to install pre build sissor trusses? Then come back and build a deck that spans the width of the building for a storage area?

What is the pitch of the roof?

What I'm afraid of is that you are thinking about building the floor off of the trusses and putting the load on the tails of the trusses. If you do this, it will fail.

You either need to carry the weight of the floor onto your walls by spanning the entire distance from wall to wall with properly sized glu lam beams, or use posts to support the floor, or buy trusses designed for attic storage space.

Cutting corners or trying to come up with something creative that isn't properly engineered is how buildings fail. With that much of a span, the are too many things going on that make it impossible for anybody to give you advice that you can use.

Do it right regardless of what it costs because if you do it wrong, it will cost a whole bunch more in the future.

Eddie

 

[Duffster]

I would use rafters but trusses GREATLY simplify the building process and make it much fast IMHO.

Not really in this case.

You need the center posts anyway so the extra espense of trusses won't justify any labor savings, if any.

 

[jcook5003]

Eddie - There will be nothing hanging from the trusses? There will be a 2x12 header carrying floor joists, the 2x12 will be hanging on every post on 12' centers, the posts and headers will be carrying all the load, not the trusses? Not sure where that came from?

 

[towmotor]

If your ledger board (the 2x12) is supported on the posts (12 feet apart), I'd be concerned that there will be bending in your ledger board.
Usually, when using a ledger board, the supports are at closer intervals.
When you see 2x10s or 2x12s used as a girder, they're doubled or tripled, something that would be rather cumbersome in the setup you've described.
I'd certainly consider placing diagonal supports from the ledger to the bases of the posts, basically dividing the 12 foot span by three.
I guess you could do that later if your loft turns out to be springier than you like.

I'll join the others in recommending the use of rafters instead of the scissor trusses.

 

[J_J]

Just some pictures to think about.

 

[ray66v]

Attic trusses were $4k more than scissor trusses. I would use rafters but trusses GREATLY simplify the building process and make it much fast IMHO.

I think you may have missed my point.

Use the scissor trusses. But put some, lets say 5 attic trusses on one end. That gives you a loft, without busting the budget.

You could also use a combination of scissor and storage trusses, which are a lot cheaper.

I say, rob a bank if you have to, but find the $4k, and get the full length attic. I have that in mine, and everyone I know, wishes they had done it. :thumbsup:

 

[jcook5003]

Also been thinking perhaps a monitor style barn would be easier to incorporate into, maybe not.

Does anyone know of a good source for pole barn building plans that would take some of this guess work out?

These plans look nice but I know nothing about the company and dont know if they are engineered or not.

Monitor Style

Gable Style

 

[LD1]

If I am reading your post correctally, You are planning on a 2x12 ledger board around the perimeter of the building on the long walls (48' walls) and plan on spanning the 36' length with floor joists???

If you do this, regular dimensional lumber will NOT span the 36' without posts/support underneath. Which means you won't have an open 36 x 48 area underneath. You will have to have posts/beams on the under side. Even engineered lumber/floor trusses are going to have a hard time clear-spanning the 36' length and would be really expensive. Even a 2x12 SYP with only a 30PSF live load spaced 12" appart would only be able to span 20'.

If it were me, and you want to maintain an open lower level, get yourself 2 36' I-beams and place them 16' appart. Then use 2x10's or 2x12's between them @ 16" centers. See attached.

I have also attached a few pics of how I did a 30x30 loft in my 30x50 barn just to give you some ideas. I used scissor trusses as well but they were built by me.

 

[jcook5003]

I guess I'm not making myself clear.

There will be four rows of posts running 48' so basically I will run 4 2x12x48 headers there will be floor joists between them spanning 12' only. The inside of the building will have posts every 12'.

 

[MarkV]

I guess I'm not making myself clear.

There will be four rows of posts running 48' so basically I will run 4 2x12x48 headers there will be floor joists between them spanning 12' only. The inside of the building will have posts every 12'.

I think some of use were getting confused and thought you wanted to run 36' without supports beside the side walls. With 12' spans you should be fine. How tall do plan on the side walls being? Head room in the loft would seem to be where you will have a problem.

MarkV

 

[EddieWalker]

OK, I missed the part about the two rows of posts down the middle of the building.

OOOPS.


Eddie

 

[LD1]

OK, I missed the part about the two rows of posts down the middle of the building.

OOOPS.


Eddie

Me too. In that case 2x12 joist would be overkill