• This topic has 10 replies, 7 voices, and was last updated 10 years ago by ajc.
Viewing 11 posts - 1 through 11 (of 11 total)
  • Underfloor insulation Q? OSB & Rock Wool again?
  • mcmoonter
    Free Member

    I dug out the flooring I had stashed. Turns out there may be enough for both gallery spaces. Its a reclaimed sprung Oak gymnasium floor. I think it will work well. Initially this was supposed to be a low cost remodel of an underused storage space. I’m getting the feeling now it might be somewhere I might use more.

    To that end should I insulate under the boards? The original floor is made of cobbled sets. It’s bone dry underneath. If I did insulate it, is the easiest way to make a floating OSB floor like I did in the studio and pack the void between the joists with rock wool?

    Richie_B
    Full Member

    If you pack with rockwool there is a danger you will make the underlying floor ‘sweat’ which with a lack of ventilation could give you a risk of rot in the mid to long term. I have seen someone install underfloor heating in dry sand laid between joists like that with an oak floor laid dirrectly above (The floor was laid floating so that it could adjust to the heating system below with the intention of fixing it later. It never has been fixed because the heating system is only on for 4 months each year so there is cyclical movement). I don’t know how they squared the construction or lack of insulation with regs but it being Grade I listed probably helped

    Bear
    Free Member

    I’d want some polythene down first probably.

    It also depends on heating, height of ground level externally, wall and floor construction, too many variables to really know what would work best.

    Fresh Goods Friday 696: The Middling Edition

    Fresh Goods Friday 696: The Middlin...
    Latest Singletrack Videos
    mcmoonter
    Free Member

    The walls are a couple of feet of stone. Heating will be 10kw wood burning stove. The cobbled floor is ground level. the floor is supported by 6×2 joists.

    I’m off oot on a ride, will check in later.

    miketually
    Free Member

    Can’t help with the insulation question, but that gym flooring looks great. I think the Brew Dog bar in Newcastle has the same.

    Bear
    Free Member

    I suspect the floor is dry because it is exposed and in a very well ventilated building looking at the type of property.

    Covering it over the moisture will be trapped beneath the new wooden floor, possibly causing the timber to rot eventually. You could add ventilation beneath the floor and any insulation you use, but you will need to take into account cold bridging. You might be able to poly the floor and build over it trapping the moisture beneath the floor, then you could insulate the whole floor.

    mcmoonter
    Free Member

    Any views on using some strawberry (or similar) netting to support some rock wool? My only concern at the moment is that some of the boards have lost bits of their tongues, were they to shrink a draught may blow up between them.

    matt_outandabout
    Full Member

    You can lay a breather paper below the floor boards to prevent drafts.
    I would be nervous of suddenly covering exposed, drafty cobbles an expecting to be dry. If there is room below for venting, then the strawberry netting supporting batts of insulation works well.

    chickenman
    Full Member

    Stating the obvious I know, but cold doesn’t rise through the floor and heat won’t sink through it either. Insulating it may make it feel warmer to the touch though. I too would be concerned about stopping air from circulating around the joists.

    Bear
    Free Member

    Cold does rise through a floor and you do lose heat to the floor. And insulating it will help cut out draught which is very important for heat losses and comfort levels.

    ajc
    Free Member

    Rockwool under the floor makes a lovely bed for mice

Viewing 11 posts - 1 through 11 (of 11 total)

The topic ‘Underfloor insulation Q? OSB & Rock Wool again?’ is closed to new replies.