Can I eliminate a floor supporting post under my cabin?
kyrral
| Posted in Construction Techniques on
I am trying to make a room under my cabin and one of the floor support posts is in the way. It supports 2 x 6 floor joints that run from foundation to foundation. What I’m wondering is if I could run a 4 x 4 at right angles to the joints and create new floor supports at the end of the 4 x 4’s. The span would be 10 to 12′. As long as the 4 x 4 didn’t bend wouldn’t this be sufficient?
Replies
Yes, if the 4x4 didn't bend it would be sufficient. However, based on your description, the 4x4 will almost certainly bend to an unacceptable degree. A 4x4 is less stiff than a 2x6.
kyrall
4x4-NO WAY.
If you're going to eliminate something, put something back that'll hold it up.
cabin or not.
Figure the span and load and install a beam that will hold it.
A 4x4 is nowhere near being adequate for that.
The rough rule of thumb is that you need an inch of depth for every foot of span. So a starting point for your header would be 10 to 12" deep.
Aw guys, U Bing hard onna guy, after all, he did not SAY the 4x4 wud B wood, eh?
A full 4x4 12 ft section of 4340M steel hardened to 56 Rockwell C would do the trick just fine - cost more than his cabin though, and weigh less than 1/2Ton.
A 4eye9.5 would work too, 12 ft would only cost him about $120 or so and be at least as strong as a hem fir 2x12
What is 4eye9.5? Also suppose I tripled the 2 x 6'S
Googlle doesn't recognize 4eye9.5.
What would be the effect of tripling the 2 x 6's from foundation to foundation? With enough 2 x 6's bolted together couldn't I theoretically eliminate a supporting post?
What would be the span that direction?
I will measure today and answer tomorrow.
12', twelve feet
12'
aka 4 x 9.5
http://www.engineeringtoolbox.com/american-standard-beams-d_1320.html
Actually, I suspect that a piece of 4x4 square tubing could handle the load just fine.
What thickness 4 x 4?
I checked and I could get 1/8th or 1/4th walls. Also I beams in either steel or aluminum. A 12' section 1/4' wall weighs about 150.
Whatever Dan says, he's an expert structural engineer. Or you could just roll your dice.
Roughly, the 1/8" wall is
Roughly, the 1/8" wall is equivalent to a single 2x12 of wood, the 1/4" wall a double 2x12