Expanding foam behind dot and dab

Discussion in 'Eco Talk' started by Lardyboy, Dec 17, 2017.

  1. Lardyboy

    Lardyboy New Member

    Hi everybody

    I have a single storey extension on my house with a solid brick wall that has been dot and dabbed internally with regular plasterboard. The room is cold in comparison to the rest of the house and I wondered if there was any reason why I shouldn’t drill a hole in the plasterboard and insulate between the brick and plasterboard using expanding foam?

    Grateful for any advice.
  2. It would likely be a patchy process at best, add very little insulation value, and would also risk bowing out the plasterboard if excessive foam were squirted in.

    Other than that, fill yer boots :)

    If you are certain that it's the wall that's to blame for the coldness, then it might be worth biting the whatsit and going 'grrrrrr'; hack off that board and D&D some insulated p'board on in its place.

    Or, if you don't mind a slight extra loss of internal space - an extra inch - then just D&D right over the existing boards - much less work.

    Even the thinnest TLB will give huge gains. I have a room with a single skin block wall and the thinnest TLB - 35mm thick. It's well cost and easy to heat.
  3. KIAB

    KIAB Well-Known Member

    Always the risk of popping off the board.

    As the wall is solid I would have gone for a stud wall/bearer on wall, would then allow you get insulation in, plus use insulated plasterboard.

    Other causes possible for coldness.
    koolpc likes this.
  4. KIAB

    KIAB Well-Known Member

    What roof as this extension got, I guess a flat roof..o_O
  5. koolpc

    koolpc Well-Known Member

    Batten is my choice too.
  6. Yeah, but best without...
  7. Bob Rathbone

    Bob Rathbone Well-Known Member

    Is the room damp? Damp air is much more difficult to heat than dry air, the dampness may be due to penetration from outside as the insulation backed boards are not so good at moisture penetration resistance as they have no real vapour barrier. Bring in a de humidifier for a couple of weeks and see how much water you pull out.
  8. Mr Rusty

    Mr Rusty Well-Known Member

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