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Damp…air brick or drainage, both ?

Discussion in 'Building' started by 3bcourt, 10 Oct 2021.

  1. 3bcourt

    3bcourt

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    I have recently bought this house and there is some damp coming through the new plaster at one side of the bay on the inside. Pics below of inside and out. I don’t know where to start with it- the most obvious is the lack of adequate drainage from the main drain from the roof but could it also be the fact this is in front of the air brick could the air brick just be blocked ?
    Do I need to get someone to dig into the concrete ?
    Grateful for your thoughts !
    78E0E0BA-C5AD-434C-966C-047199B45764.jpeg 355B96D3-E681-49C7-B1EE-E48F60CF6683.jpeg
     
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  3. JohnD

    JohnD

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    Repair the downpipes. One might be blocked.

    Walk round the house until you find the DPC.

    Is it lower than that paving?

    I find it strange that there is no drain or gulley for the downpipes.

    How old is the house?

    It looks like a cavity wall. Is water entering from above?
     
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  4. 3bcourt

    3bcourt

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    The house is late Edwardian- 1910-1920 but not sure exactly.
    the left drain comes from the bay window roof which needs repairing. I am getting it replaced (full batons and tiles) but the roofer doesn’t think this is causing the damp as it’s too far away.

    Probably a silly question but how would I find the DPC ?
     
  5. JohnD

    JohnD

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    Walk round the house. It will be two or three courses of bricks above where ground level was when the house was built.

    It it most likely to be visible under or beside a doorstep.

    Once you find it, it is pretty sure to be at the same height all round the house.

    In some cases, there are courses of extra-dense hard bricks instead, generally glossier and darker than the rest of the wall.

    Your wet patch looks to me too high to be coming from a bridged DPC, more likely a gutter or downpipe fault.

    Please stand back and take a wider pic, showing the wall from roof to paving.
     
    Last edited: 10 Oct 2021
  6. 3bcourt

    3bcourt

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    D8AE07F1-3554-456A-9971-F97ECA98BABC.jpeg
    I can’t seem to see see a clear line anywhere but I could well be being a total idiot. ‍♀️‍♀️ F71D0C1A-3DB4-4166-A4B2-F083A65629F3.jpeg
     
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  8. tell80

    tell80

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    Although its workingthe down pipe is probably inadequate for the large roof but theres no signs of blocked or leaking downpipes or splashing over from the gutters. both downpipes could have been joined into one just below bay gutter lavel.

    The dark blodges and staining is rising damp, the skirting looks shot and could be rotting on the back.
    But why the shadows go up so high on a cavity wall i dont know,maybe others with more experience wil know? Same with the long dark streak on the inside corrner?
    Why fresh plastering when selling the house?

    The plinth bricks could do with pointing and maybe relaying. the air bricks are set a bit to high.
    theres an air brickleft of the bay thats way to high. someone should go under the floor and check the condition of the joists in the front bay.
     
  9. 3bcourt

    3bcourt

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    Thanks a lot. I’ve just bought the house, I’m not selling. Looking to move in soon. I got the plastering done and I came to painting and saw the damp patch. I had a door leaning against that wall so I thought the damp may have been because of that and I did the mist coat and it’s back with full force!

    This is all really helpful as I’m trying to get a bit of knowledge before I start to get quotes as everything has been so expensive and I keep getting wild quotes for every bloody job (single female early 30s :rolleyes:) and I have no idea what the hell I’m talking about when it comes to drainage and I don’t want it to be so wildly obvious.

    I have someone coming to sand and fill the floorboards in a weeks time. Is this dangerous ? (I’ve had him booked in since may). Guessing I need to get someone to check the joists before this.

    Thanks everyone for help !
     
    Last edited: 10 Oct 2021
  10. JohnD

    JohnD

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    The downpipe and gutter are ideally placed to be the source, and the damp is high up the wall so I find it improbable that they are not guilty.

    Have a look during heavy rain, or squirt water up there from a hosepipe.

    Little roofs on bays are often neglected, and not built to the same standard as house roofs.
     
  11. tell80

    tell80

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    3bcourt, I know your the buyer but i thought the seller had done a last minute skim plastering job.

    you need to remove the skirting and the plaster to 1m high where it shows rising damp.
    Maybe you will need to knock off all suspicious plaster where you first saw damp staining, even up to ceiling height.
    replace any rotten skirting and use a render on the wall, dont use gypsum plaster.
    Dont do any floor sanding until all renderingand work in the room is finished and someone has inspected under the floor for woodrot in the joists. Someone needs togo and look carefuly for any other dark patches at interiorskirting level along the front rooms of the house including the hall

    the flashing on both bays and the porch canopywill need checking sometime.
    why do you mention drainage? theres no signs of leaaking gutters or downpipes.
    all roofs on a house, main roof bay roofs and porch cnopies are originaly built to exactly the same standards

    from the first floor to eaves the old cast iron down pipe has been replaced andthe dashed render behind it has been patched.this could have caused historical penetrating damp to enter the cavity.if it crossed the cavity it would have shown on that bedroom wall.
     
    Last edited: 11 Oct 2021
  12. JohnD

    JohnD

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    'mmmm

    rising damp, or leaking gutter/downpipe?

    I wonder which would cause a single, high damp patch, at the very spot where there is a downpipe, and not all along the base of the wall?

    Tricky one.

    It will be interesting to find out.
     
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