I had to dig out my foundation last summer because of water issues in the basement. No surprise that the drain pipes were completely clogged with a thick mat of tiny roots and mud. I was however very surprised when we started digging and found this.

The cinder block foundation had disintegrated almost entirely. Only the webbing and ends were intact. It is quite fortunate that we discovered this when we did, before that side of my garage completely gave way.

There were NO signs of termites, ants or any other pests. There were no signs of any tree or plant roots any larger than approx. 1/16" or less. (the roots you see are from a tree about 15 ft. from the wall which was dozed down and was NOT in the ditch or near the wall).

To fix, we formed a new concrete wall 6-8" thick in front of this deteriorating wall. Then we poured and vibrated 6000psi concrete into the deterioration and made a 6-8" thick concrete wall, re-enforced with 5/8" rebar pins going into the existing wall. I should add that this was also excavated about 10-12 yrs after original construction and no deterioration was noted at that time. It has been about 20 yrs since that excavation.

What is the cause of this? Is my remedy sufficient?

The home is in N Alabama-- a very humid and wet climate.

garage corner foundation

  • 2
    Maybe it's only the picture but while I see deterioration what I'm surprised at is that the cinder blocks look as if they were laid sideways on the bottom three courses with the cutouts running horizontal instead of vertically. Is that the situation?
    – HoneyDo
    Commented Feb 21, 2020 at 3:32
  • 1
    @Honeydo--definitely not the situation.
    – peinal
    Commented Feb 22, 2020 at 2:21
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    @blacksmith37: that is true--but this deterioration was NOT present 10-12 yrs after laying the block.
    – peinal
    Commented Feb 22, 2020 at 2:24
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    Putting together things you said in various comments: In 1988 you yourself laid these blocks, around 2000 you yourself excavated the area and found the blocks all in good shape, and in 2020 you did it again and found three adjacent rows completely missing a face but with no other damage to them and no damage to blocks above and below? Why did you excavate in 2000 and what else did you do then?
    – jay613
    Commented Sep 30, 2022 at 21:16
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    @jay613: Why excavated in 2000? Attempt to fix h20 leaking into the basement (~25ft upstream from this corner). What we did then in an attempt to fix the leakage issue? Installed new drainage pipe (sch40 vs thin-wall corrugated), add 6" of gravel above new drainage pipes, re-tar wall. Y to the 3 adj rows' face missing/no damage above/below. What else we did in 2000? Removed upstream gutter tie-in & made it an independent drain. Installed new sch40 drain pipe. Filled the ditch with washed gravel about 5ft deep. Add poured 6Kpsi concrete in frt of the damaged blks (& filled them with concrete).
    – peinal
    Commented Mar 6, 2023 at 19:11

1 Answer 1


I think the blocks were laid on there sides, possibly a small area for drainage. I know of no critter that eats concrete cinderblocks, hopefully it’s only a small area and if it is drainage may be the reason, I have had to add weep holes to foundation walls where a spring was discovered. Who knows this is not the correct way to do it and you may want to see how far this extends. This structure has absolutely no strength in an earthquake and it may need to be back filled with concrete if much wider than what we can see.

  • That is definitely NOT the case. I know without a doubt because my brother and I laid the blocks.We did fill with 6000psi steel reinforced concrete.
    – peinal
    Commented Feb 22, 2020 at 2:20
  • 2
    I have never seen anything like this with concrete or cinderblocks unless someone dumped muriatic or another acid that can eat concrete but even that would be a stretch.
    – Ed Beal
    Commented Feb 22, 2020 at 3:29

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