Insulating Floor

[securespark]

Hi guys

As part of a proposed bedroom refit, I would like to insulate the floor of our bedroom.

It is built over a garage and quite cold.
The cavities and (flat) roof are already insulated, so doing the floor would finish it off.

The garage ceiling is lined with PB and covered in pipes, including a soil pipe and cables. The alternative is to go from above, removing the T&G. The only sticking point there (no pun intended!) is that the floor in the bedroom is covered in linoleum tiles.

There is a possibility (I guess) of putting insulation on underside of the existing garage ceiling and relining it.

Which route would you take?

 

[endecotp]

Can you remove enough of the garage ceiling to push in insulation batts between the joists, without disturbing the pipes?

Or you might be able to get grey polystyrene beads pumped in. I've not heard of that done under floors, but I can't think why it wouldn't work.

 

[securespark]

Thanks for your reply!

In some places, yes. But others, no.

The beads sound good, but I worry about two things:

PVC cable affected by polystyrene.

Airflow cut off introducing damp.

I could put some galv conduit up to the sockets to protect the cable.

Can you fill the underfloor channels completely and avoid any potential damp due to restricted air flow?

Cheers!

 

[endecotp]

Yes you do need to protect cables.
The beads are more vapour-permeable than e.g. solid celotex boards; there are spaces between them, and only enough glue is added during installation to stop them just pouring out if you later make a hole in the ceiling for some reason.

 

[securespark]

Thanking you kindly!