Asked on Jul 20, 2012

I had a new wall put up consisting of octagon shaped blocks that you just lay down.

KMS WoodworksBarb M.Woodbridge Environmental


On top of the blocks all kinds of white spots and markings on them and they look terrible. Where do they come from?
5 answers
  • This sounds like efflorescence. If the blocks were made from cement the salts in the material used to make them is reacting to moisture. What happens is the moisture is dissolving the salts in the blocks allow it to flow in liquid stage until it reaches the outside of the block where the moisture evaporates away. The result is white deposits left behind. If you can post a photo of this perhaps I or someone else can confirm that. There is nothing you can do to stop this from occurring. If you come up with something that will, you will become quite rich. Sealing the top with clear water proofing sealer may slow down this process but in time it will begin again.

  • KMS Woodworks
    on Jul 20, 2012

    What is behind this wall?....was a liner or barrier used for moisture?

  • Barb M.
    on Jul 30, 2012

    Yes, there is a liner behind the wall.

  • Barb M.
    on Jul 30, 2012

    Thank you Woodbridge. I tried to remove them by scrubbing them but I probably made them worse.

  • KMS Woodworks
    on Jul 30, 2012 is an article that explains this a bit

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