Pole barn make over

[Slong1958]

Hey guys Im needed some help with sizing a I beam for my polebarn if possible. Ive got a 24x40 barn that Im adding on another 12 foot bay on the end and a 12 ft lean to off the rear. My plans are to close in the 2 swing out doors and add a walk-in plus add 2 18 foot roll up doors and concrete the floor. The problem is when I built the barn 25 yrs ago I only built it 9ft tall to the top of the post and Im wanting the know is it possible to put 8 ft doors in. From the ground up to the bottom of the 2x8 ive got 8 ft 5ins. so with the concrete Id have 8ft. Does anyone know how to size a I beam or does anyone have a better idea. In the pics the post that Im pointing to would have the come out to make room for the roll up doors. Ive done a little research and looked at the low clearance garage door tracks which take 8 clearance at the top.

 

[KennyG]

Sizing an I-Beam or wood beam isn't that difficult, but we would need to know the specific requirements. What is the span? What load are you carrying - is this supporting the roof or is it in the gable end? What is the snow loading in your area? I can't quite understand the configuration from your description.

 

[s219]

You must have very little snow load in that area to use a 2x8 header, is that correct? I assume it's a double 2x8 ? That is so close to minimal for even low snow load I feel like it's going to be a challenge to work with that, and even as much challenge to switch to an I-beam and gain headroom. But as mentioned, tell us the span you need to run between posts (with the middle one removed) and it will make the math easier.

If you had rafters it might be possible to come inside the header and put something beefier, but with trusses the header really needs to stay where it is now, to properly support the top and bottom chord where they meet up.

You'd be marginal to get an 8' door in there now -- really need 8' "trimmed out" opening, not rough opening. I think it's going to be a challenge to beef up the header and keep or increase the current head room.

 

[EddieWalker]

I'm not sure that I understand where you want to put the I beam?

It sounds like you want to add a roll up door. Are you wanting the I beam to be a header over the roll up door?

Why?

Roll up doors mount to the posts on either side of the door.

or are you wanting the I beam as part of the area you are adding to the building?

Why? what will it do? How much of a span will it have? Why metal and not a glulam beam? Here, I can get 24 foot long glulams for something like $250 each.

 

[Hay Dude]

Hey guys Im needed some help with sizing a I beam for my polebarn if possible. Ive got a 24x40 barn that Im adding on another 12 foot bay on the end and a 12 ft lean to off the rear. My plans are to close in the 2 swing out doors and add a walk-in plus add 2 18 foot roll up doors and concrete the floor. The problem is when I built the barn 25 yrs ago I only built it 9ft tall to the top of the post and Im wanting the know is it possible to put 8 ft doors in. From the ground up to the bottom of the 2x8 ive got 8 ft 5ins. so with the concrete Id have 8ft. Does anyone know how to size a I beam or does anyone have a better idea. In the pics the post that Im pointing to would have the come out to make room for the roll up doors. Ive done a little research and looked at the low clearance garage door tracks which take 8 clearance at the top.

I have used the low clearance doors in quite a few garages Ive built for customers. They have their place in certain situations, just keep in mind the track hangs low and can get in the way. When Im looking for clearance and need strength, I have used glulam engineered products and also have made my own flitch beams, which are a piece of steel sandwiched in between 2 pieces of framing lumber. VERY rigid and strong.
You can also conceal the header up-in the rafters, attaching the rafters to the inside of the header with properly engineered joist hangers, then nail rafter tails on the outside.
Lastly, you could slope the floor Down lower in the garage addition, but that’s probably least desirable.
You have options, just use the best one for your situation.

 

[Slong1958]

Im needing to get the roof supported and the 2 post removed so concrete can be poored then ill frame in the 2 door openings. The 2 post with the red x will be removed then the openings will be 20 and 22. Ive already got two 22x14 x 1 3/4 LVL that I was going to use and just have 7 foot doors but i got to thinking it would be nice to have 8ft doors. Im just asking if itç—´ possible to use a ibeam and be able to install a 8ft door. Who can tell me what size ibeam it would take to support the roof. The ibeam would need the be no taller than the 2x8 thats there now. It doesnt snow here much so id say no snow load. The barn roof is only supported by one 2x8 on the outside of the post and I havent had any sagging or anything.

 

[Hay Dude]

when you say I beam, Do you mean steel? If so, you need to consult a structural engineer. I was thinking you were trying to do a wood beam :laughing:
I know you want an 8 foot TALL opening, but I think we all are wondering how WIDE of an opening you desire.
What is the width of the opening?
Looks like a 16’ clear span???? If I’m correct, ask a local structural engineer for proper height and # per foot of steel.

 

[Citydude]

One is 20 foot wide, the other 22.

 

[Hay Dude]

One is 20 foot wide, the other 22.

Thanks, citydude
If that’s the case, lumber is out.
You’ll need some good size steel.

 

[Hake]

Snow load will be the largest factor in your calculations. I haven't done the math but a 10/22 steel I beam is in the ball park. Keep your spam as small as possible to accommodate the doors. Standard garage doors are 16 7 and it looks like you want 18x8' so keep your beam at 19' assuming 6" pedestal for the beam to sit on, which is plenty, typically it is ~3". It's worth setting new posts to support the beams to shorten the span.