Damp (starting high up wall)

Discussion in 'Builders' Talk' started by JAzer, Sep 12, 2017.

  1. JAzer

    JAzer Member

    Hello,
    In our dining room in the top corner, there is a big damp patch that spreads all the way down to the floor on one side (internal) and to the bay window on the other (external). The internal wall has been boarded and skimmed on the other side (yet to be painted) - there are damp patches where it has been dot and dabbed lower down. I think the situation is best described in a list:

    1. 19th Century house purchased 20 months ago
    2. This damp patch existed then (there were many more - this is the last problem)
    3. House skimmed/re-plastered just over a year ago
    4. Walls in dining room were painted maybe a month after skimming (not a good idea as still damp), the other side of internal wall is unpainted and has damp patches where dot and dabbed.
    5. This other side is single-storey and there is a pitched roof above it that runs down to this damp top corner
    6. This roof was re-felted, tiled and leaded around 6 months ago (I have taken up a tile that butts up to the damp corner while it has been raining and it is dry underneath)
    7. The whole house was re-rendered around 4 months ago (curing other damp problems)

    I would love some advice on where to go with this. Although I don't see where water can be getting in now, I can't confirm it isn't. The wall does not appear to be drying out at all. I'm a bit lost at what to do next other than hacking off the plaster and seeing if the wall will then dry out. I'm thinking of buying a damp meter to help keep track of it. Any advice on what to do next?
    Thank you!
     
  2. stubber1

    stubber1 New Member

    Have you got pictures please inside and outside
    Water tracks so even though you lifted a tile and it was dry where you looked doesn't mean it's not there unfortunately
     
    JAzer likes this.
  3. KIAB

    KIAB Well-Known Member

    Water can take some strange routes getting from A to B.
     
    JAzer likes this.
  4. JAzer

    JAzer Member

  5. JAzer

    JAzer Member

  6. JAzer

    JAzer Member

  7. JAzer

    JAzer Member

  8. JAzer

    JAzer Member

  9. JAzer

    JAzer Member

    A few things for me to add...
    On the corner, perhaps the lead needs to come round the corner and down a few more inches. I have coated this area with water repellent. Although this seems like the obvious area where water would be coming in, as the damp was there before the new roof/lead/render, I'm not convinced.
    Inside you will be able to see a pipe travels down this corner to the radiator. This is a new pipe and the damp problem was there before. There is no damp showing on the ceiling or in the bedroom above.
    The guttering needs sorting but this won't be the problem.
    As you say, water can take a strange route.
    I have ordered a damp meter to see if the dampness increases after it has been raining.
     
  10. Jord86

    Jord86 Well-Known Member

    I wonder if a lack of cavity trays at your single story roof junction could be your problem......
     
  11. stubber1

    stubber1 New Member

    Is the lead all one piece and does it get worse if the wind and rain is blowing towards it ?
    Has it been cavity filled ? For water to travel that far across and come through the Dabs something is carrying it
    And what is what condition is the corbelling (the bits under your main't gutter like) my mams friend had a similar problem that I sorted for her, that was a gutter leaking onto that (the original cast gutter used to sit on it) and was getting into her cavity and right down the inside of the house
    Other than that all I can suggest is making a few holes along the bottom of the board where they will be hidden by the skirting and blowing hot air up the back to try and dry it out and try and follow where it starts again
    Or worst case but best in the long run rip the boards off and dry the entire wall and wait for it to come through again to give you a defined starting point then work backwards from there
    As kiab said where it comes out it can go any where from coming in to getting out
     
  12. KIAB

    KIAB Well-Known Member

    Agree.

    Lead work ain't brilliant, too short at end.
    Doubt there a secret gutter (Abutment Soaker) fitted.
     
    Last edited: Sep 14, 2017
    stuart44 likes this.
  13. JAzer

    JAzer Member

    Thanks for the replies guys, much appreciated.
    I didn't see an abutment soaker when I lifted the tiles.
    The lead is two pieces. It is hard to judge if it gets worse with rain because the damp patch looks different throughout the day just because of the change of light in the room. It deceives the eyes. The damp meter should help me keep track.
    Because it is such an old house, it is solid brick walls.
    I will have a closer look at the corbelling today.
    There is on/off rain today so that should help investigations.
    Thank you
     
  14. stuart44

    stuart44 Member

    Good point about the secret gutter. With profiled tiles you can do a better job with the flashing, but on those type it's more difficult, if not impossible to get a decent seal, although running the felt up the wall enough can help.
     
  15. Devil's Advocate

    Devil's Advocate Well-Known Member

    Hi JAzer.

    I can't offer any suggestions above those given above.

    The good news is that it's a significant leak, so should be easier to trace...

    Hacking off the D&D to allow it to dry might well need to be the route forward so that fresh incoming water can then be traced.

    I'm struggling to relate the indoor pics with the outdoor ones - where's that front window-wall in your inside pics, for example? And is your house 2-storey, with damp on both levels?

    If I were to hazard a guess, I'd be looking at that lead flashing and how it simply cannot be sealed against these flat tile surfaces, so any significant rain - especially accompanied with an even gentle wind - would surely blow water under it?

    (Although there was damp before you fitted that plumbing pipe down the corner, keep that as a possible option too - it's easy to dismiss this out of hand as there is obviously a chance you have fixed the external leak and now have a leaking pipe instead :) )
     
  16. 2shortplanks

    2shortplanks Member

    I wonder what they used to stick the dry-lining on with, if they used bonding coat that would cause damp patches. As above, it's hard to relate the damp patches to the exterior. It seems unlikely that a problem with the flashing would cause all those damp patches. I suppose another possibility would be a plumbing fault.
     
  17. stuart44

    stuart44 Member

  18. sospan

    sospan Well-Known Member

    What ever the cause is, if plasterboard gets damp like that I would remove it to prevent black mold developing on the back of the boards.
     
  19. JAzer

    JAzer Member

    To explain pics...
    As you look at exterior front of house:
    In the single-storey room, on the right-hand side which joins the main house wall, this is the dot and dabbed unpainted wall.
    On the left of the main two-storey house, this is where the plastered (no dry line on this side) wall is with the damp starting in the top corner.
    The damp corner on the outside is pretty much where the lead finishes.
     
  20. JAzer

    JAzer Member

    It has been hammering it down here and I've had the tiles, lead and membrane up and it just looks really dry.
     

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