Insulating ground floor

[itsneosmatrix]

Hi All,

I am looking to insulate the ground floor of my house and found this article:

http://www.permaculture.co.uk/articles/new-carpet-insulate-first

Does this sound like a good idea, does the wood/insulation need to breath, if so does this method of insulation allow this?

If this all looks ok could someone tell me what a semi-permeable membrane is and how/where to get hold of some.

Many thanks
Jason

 

[freddiemercurystwin]

This subject has been covered thousands of times in the forum, assuming your void beneath your joists is well ventilated and there are no other underlying damp or water ingress problems then are no problems with this approach. using a a foil membrane is overkill though and not required chicken wire does work just fine and is cheap and readily available.

Typically you would proceed down one of two routes;

Either using a rigid insulation say 75mm think Celotex or Kingspan tightly fitted between the joists (any gaps filled with expanding foam), these insulation sheets can be supported on nails or battens fixed to the sides of the joists and should be as high up as possible so that there is no gap at all between the insulation and underside of the floor boards. If you go this route, do not buy it from the sheds they are a ripoff.

Alternatively you can go down the mineral wool insulation route which entails affixing chicken wire to the top of the joists and draped down so that it creates kind of baskets of chicken wire to create kind of wire baskets to sit the mineral wool insulation in. Use 2 or 3 layers of 100mm again keeping it up against the underside of the floor boards.

Which method you do is up to you, sometimes if your void is bigger enough people have been known to lie down in the void and do it all from below, avoiding having to lift the boards at all.

As mentioned lots of threads eg http://search.diynot.com/forum_sear...tbytime=0&author=&search=Search+Forum&stype=0