Cavity closing advice

Discussion in 'Builders' Talk' started by Kaylg, Aug 5, 2018.

  1. Kaylg

    Kaylg Member


    I'm looking for some advice on insulating under our inner sills.

    I've seen cavity closers but not sure if they'd fit in our scenario. I then thought would rock wool on a damp proof sheet suffice?

    The sides appear to be mortered up.

    Any advice?
  2. Jord86

    Jord86 Screwfix Select

    Square up the protruding stone with a small angle grinder, then slot 40mm celotex insulation down into the cavity keeping it a couple inches beneath the top of the stone, then wedge more celotex down on top of a piece of 18" DPC between the brick and stone to close off the cavity, keeping it flush with the brick/stone.
  3. Kaylg

    Kaylg Member

    Thanks for taking the time to reply.

    Am I right in my understanding of your explanation: so celotex in first then DPC would sit on the stone go down in the cavity then back up onto the brick with some more celotex sat in it?
  4. Jord86

    Jord86 Screwfix Select

    Pretty much yes, tuck the DPC down into the void but fold the edges up over the stone and brick once you've wedged insulation between. Cut off any excess when you come to cover with plasterboard or whatever.
  5. Kaylg

    Kaylg Member

    Nice one thanks for the advice, much appreciated.

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice