1. Visiting from the US? Why not try DIYnot.US instead? Click here to continue to DIYnot.US.
    Dismiss Notice

Anyone used expanding foam to insulate under floor?

Discussion in 'Floors, Stairs and Lofts' started by sjws1888, 2 Jan 2014.

  1. sjws1888

    sjws1888

    Joined:
    19 Dec 2012
    Messages:
    40
    Thanks Received:
    0
    Location:
    Yorkshire
    Country:
    United Kingdom
    Hi

    I've got a suspended timber floor in the sitting room and I can get into the crawl space below the floor without taking any of the floor up, so I am planning to use spray foam insulation on the underside of the floor boards to cover any gaps and therefore stop drafts coming up between the floor boards and to insulate.

    here is the stuff I'm planning to get for the job:
    http://www.foamseal.co.uk/index.php?cPath=3800003

    I'd love to hear from anyone who has actually used this sort of material before - in particular do you actually get the coverage that the manufacturers claim? Any other tips would be appreciated too.

    Cheers
     
  2. Static

    Static

    Joined:
    20 Dec 2005
    Messages:
    2,026
    Thanks Received:
    168
    Location:
    East Sussex
    Country:
    United Kingdom
    You will probably need to run full face mask and breathing apparatus for spraying in such a confined space..

    Bear in mind that if you need to take up any boards in the future you will most likely need to replace the board..

    Might want to check into how fire resistant it is..
     
  3. rjm2k

    rjm2k

    Joined:
    30 Jan 2008
    Messages:
    2,106
    Thanks Received:
    163
    Location:
    Yorkshire
    Country:
    United Kingdom
    Also bear in mind that the house which blew up last year apparently had an old fella using expanding foam cans in the cellar !
     
  4. rjm2k

    rjm2k

    Joined:
    30 Jan 2008
    Messages:
    2,106
    Thanks Received:
    163
    Location:
    Yorkshire
    Country:
    United Kingdom
  5. geraldthehamster

    geraldthehamster

    Joined:
    7 Feb 2010
    Messages:
    2,945
    Thanks Received:
    312
    Country:
    United Kingdom
    That sounds horrendous, and isn't the usual way to do it. If you can get under the floor OK, I would stuff the space between the joists with rock wool insulation, and support it with chicken wire or plastic mesh. This will both insulate and prevent draughts.

    Celotex or Kingspan board insulation is even more effective, but is easier to do with the floorboards up, so you can seal the gaps with expanding foam.

    I really wouldn't try to use any kind of spray foam, working in the floor void - if you're lying or crouching you'll end up with it all over you, and it's horrendous stuff to get off. Quite apart from the fumes, as others have mentioned.


    Cheers
    Richard
     
  6. DIYnot Local

    DIYnot Local

    Joined:
    3 Sep 2019
    Country:
    United Kingdom

    If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

    Select the supplier or trade you require, enter your location to begin your search.


    Are you a trade or supplier? You can create your listing free at DIYnot Local

     
Loading...

Share This Page