Advertisement
If you have a new account but are having problems posting or verifying your account, please email us on hello@boards.ie for help. Thanks :)
Hello all! Please ensure that you are posting a new thread or question in the appropriate forum. The Feedback forum is overwhelmed with questions that are having to be moved elsewhere. If you need help to verify your account contact hello@boards.ie
Hi all! We have been experiencing an issue on site where threads have been missing the latest postings. The platform host Vanilla are working on this issue. A workaround that has been used by some is to navigate back from 1 to 10+ pages to re-sync the thread and this will then show the latest posts. Thanks, Mike.
Hi there,
There is an issue with role permissions that is being worked on at the moment.
If you are having trouble with access or permissions on regional forums please post here to get access: https://www.boards.ie/discussion/2058365403/you-do-not-have-permission-for-that#latest

Insulate under floor

  • 13-10-2014 10:09am
    #1
    garlad
    Registered Users Posts: 601 ✭✭✭


    Hi,
    Recently had a new boiler installed in the playroom (old garage). Carpet is up.
    I have taken up most of the subfloor ply.
    I hope to insulate between the joists with something like rockwool, lay new subfloor and laminate over this.
    There is a gap below the bottom of the joists, from about 12 inches at the back of the room, to 4 inches at the front.
    Can I just fill the whole cavity, or do I need to just fill between the joists and somehow do something to hold up the insulate?
    I read somewhere that you should leave a gap below to allow the joists to breathe, but it would be much easier to just pack the whole thing.
    Thanks


Comments

  • #2
    whizbang
    Registered Users, Registered Users 2 Posts: 1,947 ✭✭✭whizbang


    No Issue if you are using rockwool or similar.

    If you were using rigid foam insulation, then you should leave a gap.


  • #3
    garlad
    Registered Users Posts: 601 ✭✭✭garlad


    Really, so no danger of rot or anything?
    All videos I have seen on youtube show them leaving a gap, although in most of the videos I watched on youtube the crawl space is much deeper and would cost a fortune to fill with wool.


  • #4
    Chalkitdowndiy
    Registered Users Posts: 28 ✭Chalkitdowndiy


    Just surprised that you'd have a boiler in a playroom or a garage.

    ChalkItDown :)


  • #5
    garlad
    Registered Users Posts: 601 ✭✭✭garlad


    Chalkitdowndiy wrote: »
    Just surprised that you'd have a boiler in a playroom or a garage.

    ChalkItDown :)

    Why's that?


  • #6
    Chalkitdowndiy
    Registered Users Posts: 28 ✭Chalkitdowndiy


    Well, if it's an oil fired boiler, for example, I thought they were best sited outdoors - that's all. Just from a health and safety perspective.

    ChalkItDown :)


  • Advertisement
  • #7
    BryanF
    Moderators, Home & Garden Moderators Posts: 10,141 Mod ✭✭✭✭BryanF


    garlad wrote: »
    Hi,
    Recently had a new boiler installed in the playroom (old garage). Carpet is up.
    I have taken up most of the subfloor ply.
    I hope to insulate between the joists with something like rockwool, lay new subfloor and laminate over this.
    There is a gap below the bottom of the joists, from about 12 inches at the back of the room, to 4 inches at the front.
    Can I just fill the whole cavity, or do I need to just fill between the joists and somehow do something to hold up the insulate?
    I read somewhere that you should leave a gap below to allow the joists to breathe, but it would be much easier to just pack the whole thing.
    Thanks
    Leave a gap. Place mesh or fleece between the joists to hold mineral wool insulation, then place sheet of plastic over top of the joists and tape/seal the joints to stop air-movement / passage of moisture.
    garlad wrote: »
    Really, so no danger of rot or anything?
    All videos I have seen on youtube show them leaving a gap, although in most of the videos I watched on youtube the crawl space is much deeper and would cost a fortune to fill with wool.
    your right to be concerned. There should be some form of vent blocks or similar visible on the outside of your house venting the subfloor. The gap below the joists should be kept clear to allow air circulation


Advertisement