Help identifying plaster type

Discussion in 'Plastering and Rendering' started by Bathfan, 24 Nov 2021.

  1. Bathfan

    Bathfan

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    I have some plaster work cracking and salts appearing on a plastered outside wall. I think this is due to a small amount of flooding outside. Now I am starting to strip back the cracking plaster and work out what plaster is currently there and how to proceed.

    The house is 1920's with lots of lath and lime plaster around the house, although it doesn't look like lime plaster on this section, may have been re-plastered at some point, is the pink gypsum?

    Would love some guidance on this, am thinking of lime plastering the wall to allow it to breathe?

    Any help appreciated.

    Thanks

    Pics attached
     

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  2. tell80

    tell80

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    Just remove all plaster or render showing signs of water damage - remove it back to brick.
    If damage and cracks are extensive then take off from floor to ceiling.
    The paint is like a skin it hasnt been absorbed into the skim coat.
    Perhaps rake out the beds and perps as well?
    Go back on with sand and lime render.

    A pic or two showing the outside of the wall might help?

    Identifying the old stuff doesnt matter.
     
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  4. Bathfan

    Bathfan

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    Yeah i guess that was the wrong question to ask. I think i just wanted to confirm it was gypsum and that it was stopping any moisture from escaping.

    I guess the first thing is to remove all the plaster and then assess it. I dont know for sure the high water outside has caused the issue, the internal brick doesnt seem damp at all. I thought the plaster was cracking and peeling as the gypsum was trapping moisture in.

    I'm quite a novice diy'er, would you say this would be ok to re-plaster?
    https://www.lime-mortars.co.uk/lime-plaster/non-hydraulic/base/25kg

    then a finish coat on top.

    Thanks
     
  5. stevethespreader

    stevethespreader

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    It would help if you tell us what kind of wall you have solid or cavity? You say high water outside? Has that been fixed?
     
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