Insulating a suspended floor

[brackendale]

the year before last we had an oak floor layed and as part of the job spec 100mm kingspan was installed between the joists, this was held in place with 20mm baton placed on either side of the joists. Once the insulation was in place a layer of builders paper (fairly thick brown cardbordy stuff)was placed over the top of the insulation to cover minor gaps this proved most effective, no more drafts !!

ps should really introduce myself as this is my first post, John the keeper of a 1907 stone fronted house in the forest of dean. I have been lurking for the past 3 years and have had some great tips from this site.

 

[Penners]

My idea has been to lift a few floorboards only, where they are loose anyway, and try to push and/or pull the yellow fibreglass stuff along under the other boards.
In your case, kkliskey, if you use the type of insulation rolls enclosed in plastic, would it be possible to tie string to one end of a roll and pull it along underneath, having only lifted two boards?

The problem with that idea for a downstairs suspended floor is that there's nothing to prevent the insulation falling out from between the joists and lying on the soil beneath - unless of course the joists are resting on soil.

 

[Lime]

piper is referring to an upstairs room floor but I don't think it would be easy to thread insulation between the joists at all.
IME nails, rough wood, screws through the ceiling, nails through the floor, wooden cross-bracing, pipes, wiring, plaster, you name it, will stop pulling insulation through.
Then there is the problem that the width between the joists will vary too.
To insulate properly and effectively the insulation needs to be a snug fit.
The basic idea of placing insulation on the ceiling below will keep heat in the room below but if there is any gap between the floorboards and insulation then the floor will not be insulated.
To insulate the upstairs floor the insulation is required to touch the bottom of the boards otherwise air circulation and loss of heat will occur.

 

[Penners]

piper is referring to an upstairs room floor

Understood, but piper's method was being suggested as a solution to kkliskey's problem.

However, I do agree with you that the chances of being able to slide a length of insulation through a floor/ceiling void successfully are probably not great.

 

[Feltwell]

Surely the carpet vs floorboards debate is also as much about personal taste and your lifestyle as it is about practicality. We've gone from a fully carpeted house to one where the entire ground floor has no carpet - every room is floorboards or tiles - and both myself and Mrs F agree that we wouldn't go back to having carpet downstairs.

We have had to insulate under the floorboards - I've still one room to do and it is noticeably colder - but especially with young kids, having no carpet is great. Spills (yes, including potty training....) are so much easier to clean up, and hard floors on young feet haven't been a problem at all. In fact the kids love it - so much easier to slide whilst wearing socks, and toy cars go much further! A big thick rug in the lounge gives them a soft warm area to play on if they want.

Noise hasn't been a problem, although it definitely would be if the first floor rooms weren't carpeted.

But equally, if you haven't got kids in the house and you're not greatly keen on the look of bare boards, why wouldn't you have carpet? As others have said it must provide insulation and stop draughts.

 

[Penners]

Surely the carpet vs floorboards debate is also as much about personal taste and your lifestyle as it is about practicality.

Of course it is. My suggestion to kkliskey was just that - a suggestion. I merely observed that the cost and work involved in rerouting cables, lifting (and possibly ruining) the floorboards, insulating between same, fitting new boards, sanding down, finishing... etc. might prompt a rethink as to the desirability of bare boards.

But as I said above - your house, your decision.