Over the summer (in humid Louisiana), we witnessed a hump emerge (about 0.5" from high point to the low point a few feet away) in our kitchen in our relatively new house. Very annoying. I went under the house, and I noticed that the part of the sill where the two 6"x6" beams meet at the center of the house was slightly upward angled over the pier. It was probably like this at installation, but then the wood probably swelled with the summer humidity.

In any case, this seems to be pushing the end of one joist, and especially the blocking between joists, into the subfloor directly below the hump. I had a structural engineer inspect the house plans and the foundation. He agreed that the center beam was slightly angled and suggested shaving down the elevated part of the sill beams over the pier slightly to relieve some of the upward pressure on the subfloor (providing support for the perpendicular joists in the meantime). He made it sound like a simple job but something tells me it won't be. To me, it seems simpler in theory to replace the blocking with a slightly shorter one that won't push up into the subfloor. Any advice on if this is a good idea, even possible, or how one might go about doing this would be appreciated.

Some pictures here for context: https://imgur.com/a/ghRVNZg.

  • 1
    Remove and replace the blocking would be easy, but probably will not do much. Those joists are the same size as the blocking and probably doing the most raising of the floor. If the house is less than five years old, the builder might be responsible for fixing. Shaving might be the fix, but would like more information about the building/footings/supports. The reason why the beam is angled is probably the most important information to a proper fix. This does seem more like a bad place to play pool/snooker than future structural problem.
    – crip659
    Jan 11 at 22:54
  • Believe me, I've been through it with the builder already. My understanding is that this is probably a materials issue -- the beam was slightly curved at installation -- and there's no actual structural issue, meaning the 5 year warranty doesn't apply. In other words, it's cosmetic, nothing more. The only question is how to fix. Thanks for the feedback!
    – Pat Testa
    Jan 11 at 22:59
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    Raising and/or lowing structural members can add/move problems to different areas. Asking for a second opinion(building inspector) not from the builder would not hurt. Is this the first time or does it repeat every year? A hard type floor(tile/planks) would not like a 0.5 movement.
    – crip659
    Jan 11 at 23:11
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    @crip - I think first step is take out blocking and trim it... then see if problem is still there a few seasons later...
    – DMoore
    Jan 11 at 23:57
  • I think the blocking is the wrong path. The beam is the issue, and I'd take care of that. It won't be too hard to shave a bit of wood off it. However, when your soil dries out, you might have a dip, so you might think about a more substantial fix involving a screw jack that you could mess with periodically. Jan 12 at 1:57

1 Answer 1


I totally get the blocking. First blocking is done here to keep the joist from twist and it helps with floor noise and movement. For this particular case the blocking is also there to add pressure to the below join in the framing. Really only one word for this... weird.

I get that they tried to cut that block as tall as possible to keep the board on the lower right from popping. It isn't normal though.

It is popping up on you because it is too big and up is the path to the least resistance. The person that installed it probably never thought it would do this. But the subfloor is way softer than concrete so the board will only push up...

Also this blocking serves no purpose on being installed so tight to the subfloor. Normally blocking is shoved to the subfloor - with nothing under it. Meaning that it is never really "tight" the the subfloor and any movement will probably push it down.

So just take it out and cut a half inch off... I would be much more concerned about this being installed on the bottom of this section than the top. Not saying things will fall apart but the purpose of this was to put pressure on the bottom plates and the join is an easy clue. This should take someone 20 mins to do and doesn't pose any issues.

If you are ultra paranoid or your engineer is - just add a strap or joist brace like below... These are $30 and mins to install and you could do it before changing blocking.

enter image description here

  • Thanks a lot for the feedback. Given that the blocking is basically there to keep the joists from twisting, wouldn't a simpler route be to keep the blocking in place between the joists as is, and just use a reciprocating saw to shave a little bit off the top? Of course, that comes with its own risks.
    – Pat Testa
    Jan 13 at 16:25
  • If you can saw it out then that is fine. I just think taking it out would be easier. Either way works. Either way isn't overly difficult but also not fun in cramped quarters. If I had a crew working and assigned someone this I would have a couple beers waiting for end of shift.
    – DMoore
    Jan 14 at 18:54

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