I have a 20 year old deck. One of the foundation posts (4x4) has sunken about an inch. The 4x4 post goes into the ground where it is affixed in concrete.

The 4x4 post is notched at the top and two carriage bolts hold it to the beam. The beam is two 2x10s.

I'm thinking the best way to correct the issue is to jack up the three joists that are sunken and put spacers between them and the beam. Is this good? If so, what should I use as a spacer? If not, any suggestions?

2 Answers 2


What I ended up doing is getting a 12 ton hydrolic jack from Lowe's for $50. Stacked a bunch of lumber up to the beam, put the jack on the lumber, carefully jacked up the beam up off the post until the level sitting on my deck went true. It was raised exactly 1 1/2 inches. So I took a spare, pressure treated 2x4 and put it between the post and the beam. Then I lower the jack, check for level and secured the spacer with hurricane brackets. After I got the good jack, the whole thing took about 1.5 hours.

  • A) Good thinking! B) thanks for coming back to post your result. C) Good that you tied the spacer in, I presume that you thoroughly reattached all the framing to the post at the new height? D) Keep an eye on this, if it's sunk, it's likely to continue sinking - you may have to bite the bullet and replace rather than just continue to repair.
    – FreeMan
    Commented May 27, 2020 at 13:48
  • Yes, the beam is connected to the post by two carriage bolts. I reused the holes in the beam and drilled through to make new holes in the post. Then reinstalled the bolts.
    – PaulG
    Commented May 28, 2020 at 14:33

I have raised a similar situation , I used some ceramic tiles to raise 4X4 off the concrete blocks they are sitting on.

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