I've just started ripping the plasterboard off the walls in my spare room to begin re-insulating and noticed that directly beneath the boards there is a rather draughty ~10mm gap that leads directly down through the suspended timber floor to the cavity below (joist just visible to left of image). This is against an exterior wall.
My initial thought is that this is an expansion gap to allow for any natural movement of the subfloor and that it should be safe to fill with a foam perimeter strip or similar to prevent draughts before installing the new plasterboard, but I just wanted to double check that this gap isn't providing some kind of essential ventilation before plugging it up.
So, safe to fill?
Ta!
My initial thought is that this is an expansion gap to allow for any natural movement of the subfloor and that it should be safe to fill with a foam perimeter strip or similar to prevent draughts before installing the new plasterboard, but I just wanted to double check that this gap isn't providing some kind of essential ventilation before plugging it up.
So, safe to fill?
Ta!