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Cavity wall insulation beads not fully removed, leaking through air bricks

Discussion in 'Building' started by Andrew Edmondson, 26 Oct 2020.

  1. Andrew Edmondson

    Andrew Edmondson

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    I'm posting this on behalf of a neighbour.

    They had cavity wall insulation beads removed when they moved in last year. Not sure why.
    The company inserted some air bricks but beads are still leaking out. They don't want to get them back because they don't trust them.

    Presumably, the air bricks will still do their job, as the beads are falling out.

    I wonder if I could use an ordinary vaccuum cleaner to suck up the remaining beads. Or perhaps they are still falling from higher up as the insulation breaks down?

    I'll probably buy an inspection camera. Always wanted one.

    Thanks
     
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  3. KenGMac

    KenGMac

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    Andrew Edmondson, good evening.

    What volume of beads are emerging?

    If small, it is possible that the remnants are or have fallen off the inner surfaces of the cavity?

    Finally, air bricks should not ventilate the cavity, a cavity should not have any air movement, air movement will assist heat loss?

    Air bricks should vent the under ground floor area only, to this end the air is allowed into the underfloor by way of a "duct" through the external walls, the duct allows the cavity to function as intended.

    Ken.
     
  4. bennymultifinish

    bennymultifinish

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    if you have a cavity wall with air bricks theres a fair possibility there won’t be a suspended floor. the air bricks are there to indeed ventilate the cavity wall.
    they would have been sealed off with poly beads installed to stop them running out. without the beads the wall should naturally be vented via the bricks , as per it’s original design. The issue of heat loss via air bricks is not a thing.
    for example you could live in a 60’s semi cavity wall built where both houses cavities will share ventilation from air bricks, and there will be nothing you can do to stop it.
     
  5. Andrew Edmondson

    Andrew Edmondson

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    Thanks for the replies.
    The beads are between 4 and 7mm
    The replacement air bricks are plastic, mortared in.
    I think there is a gradual trickle rather than a deluge.
    I've bought a borescope. Perhaps that will shed more light on it.
    I'll check if there are any underfloor vent bricks too.
     
  6. Grantx

    Grantx

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    You are wrong. Air-bricks are used direct airflow/ ventilation to a suspended floor, not to a cavity.
     
  7. JohnD

    JohnD

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    You are wrong.

    You are describing current practice.

    Former practice was different. Many of those buildings continue to exist.
     
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  9. Grantx

    Grantx

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    When was this former practice?
     
  10. JohnD

    JohnD

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    I don't know when it changed. 1970's? 1980's?

    Such buildings are very common.

    The OP is talking about a house that was built without CWI, so not a new house.
     
  11. Grantx

    Grantx

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    From experience, your dates are out.
     
  12. JohnD

    JohnD

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    Maybe.

    Have you looked at buildings all over the British Isles?

    A couple of minutes ago, you didn't even know the practice existed.

    Now you consider yourself an expert.
     
  13. bennymultifinish

    bennymultifinish

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    wrong
     
  14. bennymultifinish

    bennymultifinish

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    whats the big deal anyway. let them leak out and blow away.
     
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