Insulating Under Draughty Downstairs Bathroom Floor

Turquoise

Have recently moved into bungalow. House has great ventilation under the floor (good thing yes but makes the house cold) so will be working my way around the rooms to seal gaps between skirting and floorboards to stop the draughts.

Am not sure what to do about the bathroom though. It has underfloor heating beneath laminate and I can feel a draught coming through the tiny gap under the bath and shower enclosure. Should I just seal the gap under the bath and shower enclosure. Or would it be better to install some kind of insulation beneath the floor to stop the cold draught making the underfloor heating work harder. If the latter what type? Have heard there are board of polystyrene or something that you hang in nets from joists?

The electrician and cable guys I recently had in for other work inform me that there is a good crawl space under the floor (they didn't need to lift floorboards at all) but have not investigated yet myself. It could be that the draught is coming between floorboards but have sneaking suspicion that there may be a bigger hole under shower to allow for the waste etc going down.

ormus

i would use summat like rockwool under the floorboards.
if its a suspended floor then you will need to make some kind of support for the insulation.
simple noggins/battens will do the job.

27col

If you are going to put insulation under the floor boards. Make sure that it is tight up against the underside of the boards. If it is not, then there will be a ready made channel for the cold air to flow along. Thus completely negating the insulating effect. I have done this on several occasions. On one, I used some wide webbing, stapled into place. On another I used thin cord wound around tacks or stapled. There many different ways to achieve what you need to do. But the main thing is to ensure that there is no unwanted air gap for a draught to flow through.