Wood flooring/insulation underneath - Advice appreciated?

[Mello]

I need to replace some floorboards. I want to insulate under the new flooring, and I've seen some fibrous sheeting that does the job. Can this insulation be simply laid across joists iunder the new OSB flooring sheets, or does it need something underneath it (i.e. on top of the joists) to stop it eventually sagging?

Advice appreciated from anybody who really knows the answer...

[B17NNS]

It needs to go between the joists.

Some wire mesh stapled underneath the joists, fill with rockwool, new boards down.

Jobs a good un.

[Mello]

Thanks B17, however the ceiling underneath is 'exposed beams' so I didnt really want anything unsightly (hence the need to prevent sagging too)?

[B17NNS]

Gotcha, I assumed ground floor.

First floor just fill the void with rockwool or similar.

Why are you insulating? noise? heat?

I wouldn't lay the insulation over the joists as your boards will be all over the shop.

[ncs]

Theres loads of products on the market that will do the job, but as asked what exactly is it you need to do, insulate against head loss, sound, or both? Also, will the underside of the floor be seen from below?

PM me if you like & I'll do what I can to help.(its what I do for a living...)

Nick

Edited by ncs on Tuesday 3rd February 20:26

[Mello]

Cheers guys. Nick, I'll PM you, thanks...

Situation is that I have a lounge in an old house with exposed beams. Above is a bedroom, so I want to insulate above the beams and below the floor above. This is to stop unnecessary heat going up into the bedroom, and to -erm- reduce any noise in both directions.

So I thought I'd probably need a layer of plywood directly on the beams, then a layer of the fibreboard insulation, then a layer of OSB sheet. However, do I really need the plywood sheet on top of the beams? Or is there a better solution?

Make sense?

[ncs]

Got it now...I see what you mean.

Whats the name of the insulation board youve seen, & how much do you need?

Theres a couple of ways to do this & Im happy to look into it at work tomorrow & come back to you.

Nick

[Mello]

ncs said:

Whats the name of the insulation board youve seen, & how much do you need?

Nothing in particular, just the standard green stuff, maybe 1cm thick, in sheets that are typically about 1M * 60cm (really not fussy about the size though). However, I already have some of the OSB, so I want to use that as the 'final' top surface, it's just a matter of what goes underneath...

Cheers...