My house has a beam of 5 sistered 2x10s that are uneven.

The beam has joists resting on top of it to support the floor, and joist hangers on one side to support a lowered room.

Many of the members of this beam have fallen out (see pictures), and the joists resting on top of the fallen sections are causing the floor above to be uneven.

Is there a way to repair this beam?

beam top between joists

beam side w/ top joists

bottom of beam floor lump wall above beam

  • 2
    What is the span of the joists onto the beam from both sides? Are there any loads (posts or bearing walls) on the beam or joists? What is the span of the beam? Are there any splices in the 5 sistered joists between bearing points?
    – Lee Sam
    Jan 16, 2019 at 4:31
  • @LeeSam The beam length is 10 feet but it has support columns 2 feet in from the ends. The beam is in my basement and supports bearing walls on the upper 2 floors. The joists on the hangars span 16 feet, and the joists on top of the beam span 10 feet. As far as I can tell there's no splices - they're just butted up against each other, hence the sagging.
    – AnthonyI
    Jan 16, 2019 at 19:12
  • 1
    How do you know that components of the beam are sagging or "falling out" vs just being poorly aligned at assembly? For example, your first picture shows a piece down about 1/2" to 3/4" of an inch, with a nail near the end. No way that moved that much once nailed. Have you pulled a string the length of the beam to see if it is sagging significantly? If you jack this, I think you're going to have the same uneven floor - just higher. And cracked drywall or plaster and binding doors. Jan 16, 2019 at 20:27
  • @CoAstroGeek, I had the same initial thought, but if the beam is actually sagging that much those ends would show that much. I'm taking the OP's word on that point.
    – isherwood
    Jan 16, 2019 at 20:31
  • 1
    Interesting ... can you tell if the joist under the bulge is elevated - could be a badly crowned joist. Or the subfloor bowed off of the joist? Or could be warped flooring as another poster suggests - does the flooring over the bulge feel firm if you bounce on it? Very odd that you see the same thing on the second floor. It seems very localized for the big beam to be the problem. By the way, great job with the pics & annotations. Wish more people could tell their story well. Jan 17, 2019 at 18:17

2 Answers 2


I doubt your 5-2x10 beam is failing. Rather, it appears that it was poorly laminated together. I would NOT recommend jacking the BEAM, but rather “securing” the hangers to the beam AND the beam to the structure (building).

You have several issues: 1) structural adequacy and transfer from hangers to beam, 2) connection of sistered joists together, 3) post to beam connections, 4) post to floor connections

1) The joists that span 10’ and sit on top of the beam is not an issue. However, the joists that span 16’ and sit in a hanger is a problem. The reaction (and thus the load on the hangers) is about 650 lbs. each. That means the hangers need to be rated for such a load and installed properly. Most hangers rated to carry that kind of load have a tab that fits over the top of the beam. If these do not, then they need the bigger diameter “short” nail. Without the correct nail it could allow the hanger to settle (which it appears like it’s doing in the second photo).

You didn’t say, but if the lower floor is uneven, then you need to “re-align” the hangers, not jack the beam. You can do this by removing the hangers one at a time and reinstall level.

2) Because the hanger is fastened to the side of the beam, it needs to transfer the load to all the sistered beams. I’d install a 1/2” bolt through all the joists at 32” o.c. (between the hangers) top and bottom (which will be 16” o.c. between top and bottom bolts). Keep the bolts 2 1/2” clear from the edges, top and bottom.

3) This is an important beam in your house. It’s carrying about 950 lbs. of floor load per foot, which means you have about 4,750 lbs. of load at the posts. Get a connector that’s rated accordingly.

4) Likewise for the footing connection.

The joists and beam are structurally adequate. The beam just needs to be secured together. Jacking the beam will cause significant problems above and should be avoided if possible, unless the floor is uneven because the beam is “tipping”. If that’s the case, other issues apply.

In your original statement, you seem to indicate that there are just floor joists on this beam. However, in one of your responses you seem to indicate that there are 2 load bearing walls on the beam too. If so, those loads are not accounted for in this analysis. If so, please advise.

  • I've attached one more picture to show the wall above. This wall sits on the board you're seeing in the top of the first image. The floor is actually level on the joist side (on the main floor). What do you mean by "footing connection"? Thanks for your input on this!
    – AnthonyI
    Jan 17, 2019 at 0:31
  • 1
    Good graphics on new pic. I’m convinced more than ever you should NOT jack the beam. You’ll have many complications with walls, cabinets, backsplash, etc. if there is a “hump” in the floor where you show in the new pic, it’s probably due to the wood floor expanding. This is probably from moisture in the floor and I’d check to see if there is “expansion” gaps along the walls and cabinets. Remove the base and make sure you have a 1/2” gap or so at the wall/cabinets.
    – Lee Sam
    Jan 17, 2019 at 2:53

The beam should be substantial enough. It's a bit baffling how poorly it was built, though. Were it my house, I'd jack up the beam and fasten it together properly. By doing so you should restore the straightness and rigidity that was originally intended.

  1. Acquire a length of steel or wooden beam that's long enough to span from one post to the other and substantial enough to carry the load of the beam above. I assume that you have spot footings at the posts, but not between. Jacking between will probably crack your slab.
  2. Place wooden blocks near each post, and span the temporary beam from one to the other. Run it diagonally from one side to the other so it falls below the upper beam where you need to place the jack.
  3. Place a 10-ton or better bottle jack on the temporary beam below an intermediate member joint. Use a steel post or 6x6 wooden post with a pad block on top, centered right under the joint.
  4. Using nails set into the underside of the original beam at each end, install a dryline (carpenter's string) some distance down (say 1").
  5. With one or more helpers watching what's happening upstairs, slowly begin jacking the beam into position about 1/4" above the 1" target (string measurement 1-1/4"). This will allow some settling when you remove the jack. Ideally the beam members will slide back into position as you do so.
  6. Drill for pairs of 1/2" carriage or hex bolts through the entire beam every 12 or 16", 2" from the top and bottom of the beam. Install the bolts with washers and nuts. Tighten well.
  7. Begin to lower the jack, watching for excessive movement. If things really settle, leave a temporary post at that location while you do the others.
  8. Move the jack and repeat for each location.


  • Watch everything carefully as you work. There's potential here for damage to drywall/plaster, misalignment of doors, binding of plumbing, etc. Proceed slowly and inspect the effects of the movement regularly.
  • Be sure that you're happy with the results before drilling and installing the bolts. You don't want to have to repeat that work if you decide things won't work in the new position.
  • It wouldn't hurt to have an experienced builder have a look at things before you begin. Maybe there's more going on than what you've noticed, and making this fix could be the wrong approach.
  • Don't feel rushed to accept an answer. There are probably other good suggestions to be had.
    – isherwood
    Jan 16, 2019 at 20:26
  • Sounds good - I planned on having a contractor come in and look at it, but wanted to have some ideas of what to expect first. Thanks for your input!
    – AnthonyI
    Jan 16, 2019 at 20:28
  • There have been a lot of down votes with no comment lately, looks like a good approach to me.+
    – Ed Beal
    Jan 16, 2019 at 20:38
  • I'm the down vote - didn't have time to write earlier. You're describing a big undertaking with significant potential downsides to it to address something that may or may not be causing a problem of unknown severity. We don't even know if the beam is sagging significantly. I'd like to know more about the reported unevenness in the floor. I think it's a sloppily constructed beam, but I don't think anything is "falling out" or structurally unsound. It may well be that the floor is uneven due to the sloppy construction, but I think jacking it will simply result in a higher uneven floor. Jan 16, 2019 at 22:11
  • Fair enough. I sought to answer the question as it was asked, but you make a solid point.
    – isherwood
    Jan 16, 2019 at 22:22

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