I need to place a beam to support a ceiling (and roof above that). The span is 14 feet. Supported only on the ends. I'm thinking of 3 2x12's with a half inch of plywood between each. Is this overkill, not enough, or just right? I don't really want anymore beam than necessary, but also don't want it sagging 5 years from now.
thanks!
Frankly I would have an engineer take a look at what you are doing. You really have not provided enough information for someone to make an intelligent recommendation. I recommend the professional because they would look at the actual situation, You might unintentionally leave out some important fact in describing it that could be important.
uhhh, nobody in their right mind would HAZard a guess, or try this without Pro advise
An engineer is your only safe answer, as Meehan says. I would not depend on a carpenter or contractor to "design" the structural system. You need to look at the load path all the way to the ground. If you have a building department, they will want documentation. TB
An engineer is your only safe answer, as Meehan says. I would not depend on a carpenter or contractor to "design" the structural system. You need to look at the load path all the way to the ground. If you have a building department, they will want documentation. TB
Depends on the kind of wood and the load and its distribution.
Like, what's the load on the beam? With bending moment M = WL/8 in-lb and a total uniform load W in pounds and L = 14x12" and S = M/f = bd^2/6 in^3 and f = 1000 psi and d = 11.25" and b = 5" (3x1.5+0.5, if half the plywood grain runs lengthwise), W = 8bd^2f/(6L) = 8x5x11.25^2x1000/(6x14x12) = 5022 pounds. You might make it stronger by substituting some metal for plywood.
Nick
try your local lumberyard. usually manufacturers of engineered wood beams have engineers on staff who will size beams provided you are buying their product. LVL's would likely be the way to go here, anyway.
Sounds very strong, but what is the load? Anyone here would be guessing since none of us know the total load to support.
Thanks for the many replies. I'm sorry I didn't supply enough info. It's an old house that we're fixing up for our own use. An engineer is out of the question. What I failed to mention is that this is a kitchen ceiling where the house was added on to many years ago. The kitchen is 14x20 and the ceiling joists run across the 14. What they did is basically remove the entire end wall (the original outside wall) and left only 2 rough cut 2x4's on either side of a brick chimney holding what ever load there is there. There is a picture at this link:
Hi, Time to talk to an engineer with your blue print, REALLY!
Hmmm, I bet you don't have a building permit either since engineer is out of question. And no house insurance either....., LOL!
You are correct. No permit. I'm not building, I'm remodeling. No permit required to do what I please in my own house. Thanks for your useless reply. And BTW, yes the house is insured.
I don't think 3 2X12's will span 14 feet. You might look here
Thanks Pat, for the very USEFUL reply.
"Steve Barker LT" wrote in news:n4gTf.29565$ snipped-for-privacy@tornado.rdc-kc.rr.com:
Not true, at least anywhere in the world that I know about. I have no idea where you live, but you should *really* look at your government's regulations covering your situation. Where I live, permits are required for all structural, plumbing, HVAC, or electrical work done on (or in) my property.
Not if it falls down or is damaged due to work done without a permit. As soon as they discover work done without a permit, your insurance company will walk away.
You could build a box beam using a 2x top and bottom plate with 2x stiffeners every 16" and then box it in on the sides and ends with 3/4 ply
======================================= 2x ll ll ll ll ll ll ll ll ll 2x stiffeners 16"oc ======================================== 2x
There are span tables around the net for them
CR
You are scaring me more now. If you remove(d) an outside bearing wall, it is not just a matter of carrying the vertical load. Almost a bigger issue is allowing the ridge to sag due to spreading of the outside walls. Perhaps your efforts should be being spent carrying the ridge. How were you planning to maintain the integrity of the roof rafter/ceiling joist/top plate connection? Has the roof load been changed by extending new roof rafters to the new outside wall? ______________________________ Keep the whole world singing . . . . DanG (remove the sevens) snipped-for-privacy@7cox.net
Did the 2x4s hold it because the were the correct strength or because of luck? Just because it survived doesn't mean it was properly designed.
Could you highlight the 2x4s you're talking about? That ceiling is hiding a lot of detail that would be pertinent.
You should contact a professional for interior or exterior structural changes. That _will_ be required unless you live in some far corner of a third world country.
Mike
PS - Ignore Nick, his posting is nonsense as usual.
After reading your additional information and viewing the photo, I would have to say that I feel all the stronger than an engineer is not optional.
I can't express this in any other way, but to say:
It would be extremely foolish not to pay the cost of an engineer. Keep in mind that if it fails and you did not use an engineer, your home insurance will likely be voided.
While there may be places in the civilized world where this kind of worm might not require a permit, most areas would require a permit. Don't be too sure about your insurance. Many insurance policies will not cover you if you did not have a permit or did not follow proper building procedures and in this case it calls for an engineer.
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