I have a 1902 house that was built on a limestone foundation. In the basement, the limestone blocks flake a bit which gets to be somewhat annoying having to sweep/vacuum it up from time to time.

Are there any good solutions to seal/secure the face of the limestone blocks to reduce the flaking?

It seems the previous owners have painted in some places, but some reading tells me that is destined to fail, and in some places I can see the flaking areas have been painted. For areas that have been painted, is there any solution available for that?

I have not noticed any leaking problems, so I am only interested in keeping the flaking under control.

  • you say you haven't noticed any leaking problems, but this flaking is likely caused/accelerated by moisture. What's your drainage situation above ground like? Do any/all downspouts get water at least 4' away from the foundation and onto a slope that carries water away from the house?
    – mac
    Commented Nov 12, 2013 at 16:18
  • Is there a seasonal pattern to when it flakes? I'm suspecting that insulating the outside of it might be the key.
    – Ecnerwal
    Commented Nov 15, 2013 at 1:08

1 Answer 1


Solution to painted areas - wait for them to flake off, or else wirebrush them with a sufficiently coarse wirebrush to remove the paint. Once they have all flaked off or been removed, insulate the exterior of the foundation to below your local frostline (MN, probably deep) with either spray closed-cell polyurethane or a combination of that and rigid XPS sheets, to minimize the freeze/thaw cycles the stone is subjected to (and save some money on heating, too.) As suggested in my comment, seasonal freeze/thaw cycles are probably to blame for the flaking. Salt (wicking in and drying in place) may be another culprit.

GSA on Limestone: Characteristics, Uses And Problems

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