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Discuss White marks on new(ish) black limestone patio in the Natural Stone and Thin Porcelain Tiling area at

  1. AngryBunny

    AngryBunny Active Member


    Last summer I had a black limestone patio laid. Pretty much straight away white marks showed up on it. I assumed I’d be able to clean them off but I was wrong…

    I have read various posts on this forum which have been helpful however I’m a bit lost for what my next step should be.

    I have to used LTP Grimex and it made little or no difference, even undiluted.

    I’m wondering if I should risk using an acid based cleaner like ‘LTP Grout Stain Remover’. I’ve read never to use an acid based cleaner on limestone as it can lighten in. However I’ve also read this product can be used to remove the white marks.

    So I’m thinking maybe I could do this. On a test stone try using some TP Grout Stain Remover. Then use LTP Stone Oil to seal. Finally using LTP colour intensifier and stainblock.

    Does this sound sensible or can someone suggest an alternative approach ?

    Mark IMG_3638.jpg IMG_3639.jpg
  2. 3_fall

    3_fall Administrator. Staff Member Trusted Advisor Professional Tiler JOTM Winner Top Contributor

    SW London
    • Agree Agree x 1
  3. jcrtiling

    jcrtiling Trusted Advisor Professional Tiler TTA Member Top Contributor

    Is your stone sealed already
  4. AngryBunny

    AngryBunny Active Member

    Yes it is
  5. Paul C.

    Paul C. Trusted Advisor Professional Tiler

    First off, don't use Grout Stain remover, Does just cause marks, it will dissolve the limestone and etch it. Instead, try the LTP Powerstripper to remove any previous sealer. Seal with the the Colour Intensifier. Not wise to mix oil based followed by synthetic as the latter will just film over. Just stick to the one.

    What was it sealed with previously and also, is there a membrane under the concrete slab/screed?

    Aaaannnnndddd....... if it is a newish screed, when was it laid (month), how thick is it, and long was it left to dry before tiling?

    No further questions your honour.
    • Friendly Friendly x 1
  6. AngryBunny

    AngryBunny Active Member

    I had the patio laid for me so some of the questions I can't give an exact answer.

    I've text the company to ask them what type of sealer was used.

    There was a membrane laid. I know they used concrete to secure the stone to the ground. Was this incorrect? ( I know in a house you can lay a screed then leave it a month to dry out), is that what you're supposed to do with a patio as well and is this an issue with moisture escaping as it cures?

    (It was laid in October I think)

    (It's a bit disappointing as this company have good reviews, etc)
    Last edited: Feb 6, 2018
  7. AngryBunny

    AngryBunny Active Member

    I found a photo I took after they laid it (if that helps).
  8. Tile seller

    Tile seller Active Member

    I think the same as Paul. C
    Strip it and reseal. Can't see what else can be done.
    I think for a similar look, slates a much better option for exterior use.
    This blk limestone is prone to uv and acidic rain damage from what I've read.
    • Like Like x 1
  9. Tommcd

    Tommcd Active Member

    • Like Like x 1
  10. jimthetiler

    jimthetiler Active Member

    Natural stone will get a natural patina over time
    the elements will do the job for you,Its a waste of
    money and time trying to put a hold on nature.
    stone looks better when it has aged.
    • Like Like x 1
  11. Simon Dale

    Simon Dale Professional Tiler

    wear it in not out !
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