Viewing 19 posts - 1 through 19 (of 19 total)
  • paint / plaster problem – possible damp?
  • thekingisdead
    Free Member

    I have a problem with paint bubbling / peeling off a wall.
    Its occurring in an isolated location. Im resigned to hacking the plaster off, inspecting the brickwork and then getting a plaster to make good.

    Could it be possible that the DPC (chemical) has failed and its “rising” damp from the ground? Any other potential causes?
    Its an internal wall. No potential sources of a water-leak (pipework etc)
    [url=https://flic.kr/p/Um5mRm]Untitled[/url] by NRH, on Flickr

    [url=https://flic.kr/p/Tbc5cv]Untitled[/url] by NRH, on Flickr

    jam-bo
    Full Member

    water can go a long way before it comes out. you sure there isn’t a leak.

    thekingisdead
    Free Member

    Reasonably sure Jam Bo – only the lower 1/4 of the wall is affected.
    A leak from above I’d (obviously) expect issue on the entire wall.

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    gravesendgrunt
    Free Member

    There’s water coming from somewhere under that wall,you’d need to pull up floorboards to have a proper looky to see the cause.

    jonba
    Free Member

    What are those pipes on the left of the photo.

    I wouldn’t assum anything. It may be that water is dripping down the inside causing damp at the bottom. Your best bet is to minimise damage but have a proper look. Probably lifting the carpetted side is easier?

    I thought rising damp was a myth? Isn’t it controversial? But you do look like you’ve got damp, looks the same as mine!

    thekingisdead
    Free Member

    Thanks GravesendGrunt.

    Concrete floors tho. This sounds like it could be a ‘mare!
    😕 😯

    Pipes to the left are radiator pipes. They’re not the cause, as far as I can tell. (have had a good look at them)

    nealglover
    Free Member

    Is it a stud wall or solid.

    If it’s a stud wall, then could coming from above. Hitting the bottom timber of the stud wall, and then soaking up the plasterboard.

    Very unlikely to be coming from below in my experience.

    thekingisdead
    Free Member

    Its a solid wall.
    Could the issue be caused by sealing the plaster with diluted PVA?
    In my naïve youth (ahem) I *might* have sealed the freshly plastered walls with PVA (not dilute paint as I now know to do!).
    Seems plausible from what I’ve read about PVA stopping the plaster being able to breathe, but wouldn’t explain why its localised to this one wall (and nowhere else).

    Squirrel
    Full Member

    Have a good look at the floor, ideally use a dampmeter (yes, they do have their uses). A leak from a pipe buried in the floor or something dripping onto it (eg a leak behind a washing machine) can manifest itself a long way away.

    gravesendgrunt
    Free Member

    OK- you didn’t mention this is fresh plaster that this is happening to,was it allowed dry before you primed and painted it?Why was this plastered/re plastered in first place?

    thekingisdead
    Free Member

    Was re plastered as part of general renovation – I moved a doorway.

    It’s new plaster but not fresh – a few years old.
    It was fully dry before priming / painting.

    Cheers,

    timba
    Free Member

    Pull the carpet back and have a look under there; might not show anything if the floor has a poly membrane lapped up the wall. Least damaging option

    Pull the skirting off (might not show anything as above). More damaging option

    You can get plasters that will control the damp (e.g. Limelight) that can be applied to damp surfaces, but far better to tackle the cause

    wrightyson
    Free Member

    Stupid question does it feel damp? You don’t need a damp meter to tell that.

    josh145
    Free Member

    salt coming through/efflorescence, but that’s a sign of damp. sealing the wall in PVA won’t of done any harm.

    andyl
    Free Member

    or it’s coming down the door frame to the bottom and then wicking through the plaster.

    Plaster is now knackered. Hack it off to 1m up and take a proper look.

    Where is the bathroom or kitchen in relation to that wall?

    honeybadgerx
    Full Member

    Looks spot on like rising damp. You could try sanding paint off and re-painting with a highly breathable paint (Earthborn clay paint or similar), or you may need to hack of the plaster and re-do with a proper breathable plaster (i.e. lime). There’s nothing wrong with having a bit of moisture in the walls, it’s just when it get’s trapped in/leaves salt deposits it causes an issue.

    thekingisdead
    Free Member

    Thread resurrection – I’ve hacked the plaster off one side – and before I have it re-plastered, would like to “repair” the DPC.

    2 options as I see it:

    1) Support ceiling with an acro, remove the mortar from a course of bricks & lay a proper DPC

    2) Drill the mortar & use a chemical DPC treatment. For such a small section of wall I’d prefer this option, seems less hassle.

    Are the DIY chemical DPC treatments reliable? Before I pay the plasterer to repair I’d prefer the to use the best treatment going (even if it is more hassle).

    Cheers,

    Squirrel
    Full Member

    Saw through the mortar joint, insert dpc, pack with semi-dry mortar. Do it in short sections overlapping the dpc. Be aware that the wall will stay damp below the dpc.

    honeybadgerx
    Full Member

    Alternative: plaster with lime (you can get pretty mixed bags of modern stuff that’s pretty easy to use) then paint with breathable paint/limewash. This will let the wall breathe and not trap in the damp.

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