I have a 23′ X 25′ garage with a set of center beams running f to b. Beams are (3) 2X10’s nailed together, each approx. 11′ long, resting on 6X6 post in center, 7′ off floor.
I noticed the ridge sagging and had the forethought to jack up the garage loft and add 4X4 posts between the center beams and ridge board prior to a re-roof job.
However, I now notice the center beams have a bit of a sag in them. I’m concerned that the lamination may give way – I can see slight spacing between the outer 2X10 and the center one. Not good.
I’d like to jack these up in the center of each and strengthen them – perhaps adding a through bolt pattern? A plate of some sort? Rather not replace these beams if I can help it, but above all want it to be structurally sound.
Thoughts?
Thanks.
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Replies
A sketch or some photos would go a long way here. From description I can't tell what your beam is carrying. Floor load at the loft? What width of floor? Ridge board/beam loading? Is the beam spliced along the span or just at the post location?
Also, the ridge sag makes me wonder if you have rafter ties across the garage.. Hard to say what is going on honestly without a bit more information.
Beam is carrying 2X6 floor joists above, 16"OC; ply floor above the joists. Not significant floor load in loft. 2X6's are approx. 12' long so floor the same in each of 2 bays.
Upon further inspection, 2X10 laminated beam is made up of solid 11' span on outside 2X's; center of each beam is combo of 4' and 7' sections.
Pics 1-4 show beam sections - and 4X4's rising above. Pic 5 shows 4X4 penetrating through loft floor and supporting ridge board. There are (4) 4X4's in total; (2) per beam section.
Not the question you asked - but 2x6 floor joists spanning 12' do not have much of a capacity (maybe 20 psf live load). I would really limit what you put up there.
As far as your beam - It sounds like you basically have a (2)2x10 beam with some spliced plys in the middle spanning 11' and carrying a 12' strip of floor and some roof load. If this is your case - that beam sounds like it is overspanned and likely is overstressed with just the dead load of the structure. Adding bolts is not going to help much and adding plys of a deeper member to the outside is not going to be fun with all of that electrical mounted on it.
My best advise (depending on the garage door layout) would be to add posts in between each existing post. This would cut down the span of the beam to a reasonable length. Good luck with the project.
Thanks for the advice. Not much weight on the floor up there - a few small bikes, molding, empty this and that. Mostly seasonal stuff.
The beam is made of all 2X10's - just two-pieces sandwiched in the middle of each. Contractor must have been short 12-footers that day.
I'd like to avoid adding additional posts. Instead, I'd rather look at switching out the beams for either steel or some engineered beam. This rather than a catastrophic failure with a heavy snow load. I'm in upstate NY.
In that case I would look at getting a local engineer involved.