Yesterday I was looking for ants in the crawlspace of my house, didn't find any ants but found an issue with one of the roof overhang support posts. It's sitting on top of a concrete block that they put right on top of a dead tree trunk. The tree trunk has been decomposing for the last 40 years and now it doesn't seem to provide much support. The block visibly shakes if I kick it. The overhang beam seems to be sagging a little bit too, maybe 1/4" but not very visible. The rest of the beams and posts are fine. Beams seem extend into the house for 2/3 of their length, but I can't be 100% certain it's the same beams inside the house, although they look the same.

My plan is to support the overhang beam with a jack and another post, then take out as much of the tree trunk I can get out of there. Finally put some gravel into the space, pour concrete over it, put the existing block on top, let it dry and put the post back.

How does this sound? How far should I jack the beam for this to not break anything?

beam, post and concrete block view from the outside

post and concrete block view from under the deck

1 Answer 1


That sounds great. Jack the beam to just above level so you can more easily refit things and allow for slight settling. Have an observer help you make sure you don't crack things up. Of course, it depends on whether the beam is continuous as to how far you can go. Non-continuous beams will probably move with fewer interior side effects, so you may be able to go further if needed.

FYI, concrete doesn't "dry". It cures chemically with the aid of water. It should be kept damp for several days at a minimum.


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