Sealing damp walls with pva before rendering

Discussion in 'Plastering and Rendering' started by qubit, 13 Oct 2008.

  1. qubit

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    Hello I have previously had loadsa problems with dumb builders browning over removed chimney patches (on the internal side of an outside wall :eek: ) and using the same black soot soaked crappy bricks which draw in like mad any rainwater and moisture from outside and makes big patches since they used a gypsum based plaster and not sand cement.

    Anyway now there's one chimney left which I intend to do myself (I've bricked it up using only bricks with no trace of soot or carbon) and plan to use 2 coats of 3:1 sharp sand cement with waterproof (rendamix) I am hoping this will be enough to stop any hygroscopic salt problems

    As an extra measure should I coat all the brickwork with a water/pva mix will that "seal the brickwork" in any way, normally I would just damp bricks with water before applying render

    Also between coats and before the final finish plaster coat should I pva the coats or just damp down with water?

    Oh and next time as an extra precaution could I paint some bitumen paint on the internal layer of the external layer bricks (solid cavity wall) to restrict any moisture coming into the internal brickwork has anyone else done this?

    Any help greatly appreciated :rolleyes:
     
  2. bikerm4

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    Think your first mistake is calling builders dumb. You then decide you can do it better and from your post its clear you havent a clue what to do. Also please explain what a "solid cavity wall " is.

    Reading your previous posts it seems your more than likely the "dumb" one.
    Good luck in your projects, looks like you'l lneed it.
     
  3. kingandy2nd

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    A bit harsh there bikerm4, but biker’s right… there’s no need to insult your builders.

    In answer to the title of your posting, PVA won’t seal a damp wall. If it is damp, it's best to rectify the source of the damp before rendering or plastering.
     
  4. qubit

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    Thanks for the replies Mr bikerm4 and Mr kingandy2nd

    Well bike if you had been left with these problems of massive damp patches on 3 of your walls left by builders who supposedly had experience in these matters and were paid a lot of money then when asked about it blamed everything else but their work (like leaking roof, chimney, etc) even though I have actually removed the chimneys totally and had everything checked by a roofing expert and still have the same problem then I think you would be tempted to call them dumb easy to judge from a distance eh

    Thank you for your informative reply Mr Andy that's what I needed to know

    I don't come onto this forum for human relations lessons I just need certain information, timewasters like bike don't give any useful information just insults what a clown
     
  5. noseall

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    use an s.b.r. and cement slurry to hold back any sooted bricks or salt saturated bricks.
     
  6. qubit

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    Thank you Mr nose for your reply is it okay if I use cement/water slurry painted on?
     
  7. noseall

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    no, as it could end up to brittle and may still bleed.
     
  8. qubit

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    Okay than :D k you Mr Nose very helpful
     
  9. helen45

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    I am sorry to say if you've seen what the builders done to my property you would do more than just insults.
     

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