Best way to insulate under floorboards

Grenage

I wouldn't bother with a vapour barrier if I was just using rockwool batts between the joists, assuming that there are air bricks to ventilate the floor void. If I was going full rigid board from beneath, sure I would - it's barely any more effort.

Whether it would make a room much warmer is another question.

hohum

yes green building forum a good idea.

Your biggest win from a cost/ results point of view would be to put down a carpet. I know people love wooden floors but I've lived in far too many draughty houses to be a fan!

If you don't want to put down carpet, and do insulation, a rug is still a valid option which will add to your thermal proofing

Also you can insulate cracks in floorboards http://www.theguardian.com/environment/blog/2011/dec/16/1

LUHG1878

We had similar issues in our house with a lack of insulation, a 1920's bungalow.

The double glazing made a big difference, as did the wall insulation, we then got the loft insulated for free under one of these energy saving schemes, but we still found that most rooms lost heat quite quickly.

Not sure why, but these companies are happy to do the loft under the scheme for free, but not the suspended floor, which is equally as important, I don't get it...

Anyway, I bit the bullet and started insulating the suspended timber floor myself. I have to say it has made a big difference. I am only part way done, but the difference in temp between a room that's done, to one that hasn't, is about 3degC, and the heat stays in the room longer too.

I didn't bother with a vapour barrier, I don't think it's necessary. I ended up going with Rockwool slabs, easy enough to handle, just make sure to wear goggles and face mask, as the particles do get everywhere!

And, if space is tight under the floor, measure, cut, and label your insulation beforehand, and it's less fiddling when your under the floor.

JP08

We had a similar problem when we moved in. Nice varnished floorboards. :O)

Reality is gaps and draughts - and they show the dust far more (and it moves around far more) than carpet.

We've carpeted the whole lot. Thick underlay and good thick carpet. Can comfortably walk around bare foot this winter. Nice.

Boards look good, but that is the only good thing about them.