Insulating existing boarded floor......Help please

[aspley]

In order to improve heat retention I am looking to lift existing floor boards and apply insulation either between or on top of the joists.
Question is what is the best insulating material.....would it be slabs of polystyryn between the joists or something like a Triso 10 foil insulation applied on top of the joists.

Any advice/observations will be gratfully received.....Ta

 

[tapir]

disclaimer:I am not an expert but is there an increased fire risk when using polystyrene?

 

[aspley]

when I talk about polystyrene I mean something like 'wallshield' which I presume meets building regs including fire issues

 

[mointainwalker]

@tapir

It wouldn't be right to say there is an increased fire risk because polystyrene does not spontaneously ignite and although it burns fiercely if lit, is at little risk beneath the floor.

aspley

My suggestion would be to use fibre wool and certainly forget Tri Iso over-hyped junk.

Fibre-wool is the cheapest insulant in pnds per degree heat saved. You can fit it between the joists but you will need something to hold it, normally some kind of mesh between the joists to support it. Fibre wool is also fire-proof.

Re building regs and fire-proofing. Believe the only thing covered is doors and house layout to give time to escape. fairly certain they do not cover insulation.

 

[tapir]

Cheers Mountainwalker - my point was more about the effects of polystyrene burning (eg gives off cyanide).

 

[aspley]

Thanks for that M......will go down that route