How big of beam to span 16 feet in my pole barn?

[unioncreek]

My pole barn was already up when I bought my property and I use is more like a garage than just storing things in it. I would like to remove a couple of posts and put beams in to open up the space. The barn is build with 6x6 posts, 12 feet on center, it is 36 feet wide. I want to remove one of the center posts by cutting it off and putting in a beam to support that section of the roof. Is this doable.

Thanks,
Bobg

 

[tc35dforme]

<font color="blue">Is this doable. </font> Yes.

But....There are way too many issues involved in selecting a structural member. Your local codes, roof framing, wind and snow loads, connection techniques, bracing, etc,etc,etc....

Get some professional advice. A local home center or lumberyard can get you started in the right direction.

When people ask me a question like " ... how big a beam do I need ?... " I like to respond, " How deep is a well ??

They usually reply " it depends...." and I say "Exactly" /forums/images/graemlins/smirk.gif

 

[Farwell]

If you do not want to do the code number, of course I always do things by local codes, 2 each 2" by 12" by 16 feet supported well on each end with 2" by 6" by 12 " length boards spaced and nailed vertically every 24 inches may very well take care of what you need and then some. But don't quote me because I am no carpenter. (this is what I did on advice from my contractor for a 21 foot span and living in Michigan this should take care of a good snow load as well). This may be over kill but I tend to go over board rather than under.
Farwell

 

[bczoom]

Bob,

First, welcome to TBN.

Like tc35 mentioned, there's other questions.

I have taken Farwell's method (I think) of the doubled up 2x12" but I put 1/2" OSB between the 2 sheets for extra strength for openings.

A couple questions:
You said you're current construction is 6x6", 12' on center. If you remove one of the 6x6's, aren't you now at 24' and not the 16' you mentioned in the subject line?

Is the opening you're making going to be just that? (left open) or are you going to hang doors or something from it?

Do you have any pics of the area so we have a better look at what you're going for?

Can you let us know approx. where you are so we can consider things like snow?

What is the roof material and structure that will need to be held up by this beam?

Brian

 

[EddieWalker]

Doable, yes.

Practical, hmmm?

You mention that your barn is 36 feet wide with beams set on 12 foot centers. How did you come up with a 16ft span?

For 4 feet more span, I'd say your crazy to waste your time and money.

If you mean to span the total distance between the posts and go for 24 feet, you better get an engineer for that one. 16 feet isn't that big a deal for some 2x12 with plywood. Garage doors do it all the time.

If you really want to increas your 12 ft span to 16 foot, then your talking about relocating one or both posts.

What are they supporting?

Is there anything tied into the beam?

Taking out one piece of wood to replace it with another affects every part of the framing around it. Lots of times it's not a significant change, but without pictures and/or an onsight evaluation, you'll never know for sure.

Eddie

 

[unioncreek]

Yes, I made a mistake in the subject of 16 feet, I really want to span 24 feet. The post I want remove supports 3 - 2x8's bolted together for the roof. The splices for the 2x8's are all above the post, I don't know why the guy that built is did it this way , but he did. Roofing material is tin. I want to remove two posts and put two beams in. The opening for the building has two 12 foot wide door in it already. This would give me a clear span of 24 x 24 which would make it easier when working on tractors or cars instead of having to work around the posts. I thought if I could do it at a reasonable enough price it would be worth doing.


Bobg

 

[beenthere]

What are your options for beam material? Wood, laminated wood, steel I-beam?

Choice will depend on the elasticity that you want in the floor above the beam. Depth of a beam is going to be critical, if you want room to move beneath it.
Do you know the floor load on the beam?

I replaced 4x4 posts (were on 8' centers) in my garage with a steel I-beam (spec'd by my architect) for a 24' span, holding joists up for a 30' span. The beam depth was 16" deep, just to give you some idea. There is no other weight other than the floor above on that beam.

A pic or two would help here. /forums/images/graemlins/wink.gif

 

[jjcc246]

go to a lumber yard and they will spec out a lam-beam for you that will do the job. the beam may be over 16" wide so you may lose some head room.

 

[bczoom]

Bob,

Switching to 24' changes things...

A picture is worth a thousand words. Can you post one (or more) with descriptions of what you want to remove/replace?

Mentally, I'm seeing a 24' span across the front of the building and a post right in the middle that you want to remove. If that's the case, I'd propose you take tc35's advise and start getting professional advise. You may need to start looking at steel I-beams.

I may not be seeing your sitution correctly. Why can't you get the tractors/cars through a 12' opening? My doors are only 10' wide and I get through OK.

 

[DMF]

I spanned 26' in my house. I built a loft in my great room (over the kitchen and dining room) and I didn't want any posts to spoil my view. I used three 3" x 18" laminated beams, glued, screwed, and nailed together. From that I attached a ledger board and ran my floor joists 14' to the gable end wall. Granted, my beam had to support an entire floor in a sense, but it also doesn't move...