Insulating underfloor

[David2749]

Hi
My daughters 110 year old house has a void under the floor boards, I'm thinking of insulating the under the floor boards with kingspan 25mm insulation boards.
Is this a good idea or what?
Cheers

 

[KenGMac]

David2749, good evening.

Short answer is yes.

If you can afford it the thicker the better as far as Insulation is concerned.

Make sure the Insulation is hard up against the underside of the flooring, Infill and gaps to each side with expandable foam, Retain the insulation with timber straps nailed to each side of the joist, the timber will not have to be full length of the insulation and can be any material you can find.

I have seen the Insulation cut into strips, the strips of insulation are a "mean" width, the Expanding foam can make up any gaps.

Ken.

 

[David2749]

Thanks for this, just what I thought would need to be done.