The sandstone wall is turning brown and black in places and I’m not sure how to restore is back to original appearance. Are there any cleaners which can be used? A picture is attached.

Thankssandstone wall

  • This just seems to be the natural color variation in the stones, which to me looks pleasant. You could try sandblasting, but after a while, iron in those stones will again oxidize and darken, unless the stone is varnished. Dec 27, 2019 at 2:37
  • @DrMoishePippik I'd strongly advise against any sort of finish; it would be a permanent choice. Dec 27, 2019 at 13:17
  • @DanielGriscom, agreed, it was mentioned only to show the futility of surface cleaning. Dec 27, 2019 at 20:29

1 Answer 1


Pressure clean it with at least a 3000 PSI power washer. Spray first with two parts water to one part bleach. This has worked for me countless times for dirty stone. Your stone looks pretty darn good and doesn't appear to need any cleaning.

  • 2
    We restore/clean a lot of historic buildings and it’s important not to deface the original texture. While I’m sure this is not historic, I’d test an area before proceeding. You could damage the texture and/or mortar.
    – Lee Sam
    Dec 27, 2019 at 3:40
  • @LeeSam Thanks, a common precaution I failed to mention.
    – JACK
    Dec 27, 2019 at 13:02
  • Thanks. This is not historic by any standards since it is our house wall. I’ll try the bleach first since pressure washing hadn’t helped last time.
    – Gary
    Dec 28, 2019 at 14:00

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