insulate suspendend wooden floor

RobAMerc

folks,

we are renovating a house with suspended wooden floors.
My priority is the walls and ceiling ( both being done ) but I am thinking, should I insulate the floors too ?
Is there a relatively easy way without taking them up thats effective ?
Is "draught proofing" enough ? I was thinking of just using a heavy carpet underlay, or do I need to rip the floorboards and use rockwool and put back down new osb flooring ?
thanks

fred funk }{

I'd lift the floor boards and install polyiso between the joists.

BryanF

Carefully lift floor boards, install fleece to support insulation, then mineral wool between joists, install air-tight membrane/vapour barrier taped & sealed and relay flooring/ expect % new flooring required.

Calahonda52

RobAMerc wrote: »

folks,

we are renovating a house with suspended wooden floors.
My priority is the walls and ceiling ( both being done ) but I am thinking, should I insulate the floors too ?
Is there a relatively easy way without taking them up thats effective ?
Is "draught proofing" enough ? I was thinking of just using a heavy carpet underlay, or do I need to rip the floorboards and use rockwool and put back down new osb flooring ?
thanks

see here for some ideas
https://www.nsai.ie/S-R-54-2014-Code-of-Practice.aspx

The key issue here is stopping the wind passing through the insulation, so what ever u use to support the insulation will need to stop the wind, therefore the old side of chicken wire suspended underneath was largely a waste of time.

Fred mentions a rigid insulation so the model there is usually nail 1 inch sq strips along the sides of the joists and then cut the rigid to suit, taping joints and filling any gaps.
sealing off against the wall at each end will be slow and tedious but essential for it to be airtight: air loss = heat loss, so if the wind can pass between the rigid and the floor boards then its a waste of time money etc.

Power cables will need to be sleeved to prevent overheating if buried in rockwell etc, or lying on rigid that has no alu cover as the pvc in the cable reacts with the rigid.

the joist closest to the wall at each end will be tricky so just focus join the airtightness and don't worry about the insulation too much.

Bonzo Delaney

BryanF wrote: »

Carefully lift floor boards, install fleece to support insulation, then mineral wool between joists, install air-tight membrane/vapour barrier taped & sealed and relay flooring/ expect % new flooring required.

Out of curiosity and future knowledge why would you chose mineral wool over say 75 +mm rigid insulation for suspended timber floor insulation. I've a similar job coming up in the near future and would like to know which is the best option. Thanks. Bonzo.

BryanF

Bonzo Delaney wrote: »

Out of curiosity and future knowledge why would you chose mineral wool over say 75 +mm rigid insulation for suspended timber floor insulation. I've a similar job coming up in the near future and would like to know which is the best option. Thanks. Bonzo.

Natural breathable material that can be pushed into non square spaces between timbers that absorb and realise moisture v petrol chemical based, not recyclable, smouldering, not breathable, will always leave insulation gaps etc