Jack post

Jack post

I bought a jack post. Then I bought two more. Then I bought a big adjustable wrench to have more leverage to crank them. The end result, after several attempts (other than a straining workout) is that in the single section I was trying to lift the beam, it has moved up approximately an eighth of an inch. Since I’m trying to raise it by over an inch, I decided to rethink my tactic.

Cut floor joists

Cut floor joists

Part of the problem is that several of the floor joists, which are 2x10s spanning the whole width of the house, were cut at some point to allow access to the basement from the front bedroom on the first floor. This was then closed up at a later date. When they cut the joists they were no longer supported by the outside wall on one side, resting entirely on the beam. Generally you would add a cross member (or a few) to tie the cut joists to the joists that were not cut. Instead, someone probably much later put in some 2x4s so they’d have something to hang drywall from. Not surprisingly this is now the lowest part of the beam, since it’s bearing considerably more weight than it was designed to. We’ll replace the cut joists when we rip up the first floor subfloor, but for now we need to work with what we’ve got.

Another problem is that the jack posts I bought ($45 a piece from Menards) are rated for between 9,100 and 18,000 lbs. That sounded like a lot, but recalling that we removed 9 tons during first floor demo alone, it’s very likely that the weight the beam is carrying is higher than that. The dome in the steel plate at the top of each jack post has buckled, which is probably a good sign they’re not up to the task.

Jack posts and rotted column (base)

Jack posts and rotted column (top) Jack posts and rotted column

After some discussion and research, I arrived at plan B. The first step was to move the jack posts to either side of the rotted column a bit further down the beam and take any remaining load off of that section. Then I took out the column, which by this point was basically hanging from the beam.

Rotted column removed

Rotted column removed Rotted column removed

The damp dirt beneath the column explains the rot, but it’s concerning since I don’t yet know where the moisture is coming from. That mystery will need to wait until we dig up the floor. With the column removed I can now cut off the rotted section and use it in conjunction with the 50 ton hydraulic bottle jacks I ordered, which will arrive in a few days. I’m pretty sure they’ll have the necessary strength to lift the other section of the beam up. I’ll cover that in more detail when they show up.

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4 Responses to Beam Project: Leveling with Jack Posts

  1. I have a jack post in my “garden flat”…but I never gave much thought to the fact that it and two wooden posts are all that support the beam bisecting the house.

  2. Damp dirt under the columns?! I would have thought that they would sit on a stone or concrete footing!
    If you have no stone or concrete footing to rest the bottle jack on, you may just push it into the ground while trying to lift that center beam. Oh boy!

  3. Matt says:

    The columns predate the basement floor and there doesn’t appear to be a footing of any kind. Maybe there’s some stone down there and the dirt I’m seeing is just decomposed wood, but I haven’t started digging yet.

    The bottle jacks will sit on the floor, and while the concrete may crack I don’t think the jack will sink into the ground. Since we’re eventually digging up the floor I don’t really mind if it breaks.

  4. Reuben says:

    I’m very much looking forward to your future posts about leveling the floors. This is a cool project. I hope you’ll be as detailed as possible. I may need to do something like this myself before too long.

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