Cold floor

I've got a timber sub-floor (ground floor flat with vented crawl space) and have laid 6mm Depron and wood effect vinyl throughout. The insulation has moved which has moved the vinyl and absolutely everything leaves an impression in the floor so I am about to take up the vinyl and overlay the Depron with 6mm ply before relaying the vinyl but I'm also considering adding 7mm fibreboard sheets over the Depron before laying the ply because the floor is SO cold.
Is this likely to make any difference warmth wise or am I going OTT & spending money unnecessarily??

6 mm of polystyrene and a bit of fibreboard - total 13 mm are not going to keep you warm.

What you need to do/have done is insulate under the floor boards with 100 mm - or 150 mm if poss -of fibre-wool or polystyrene between the joists.

Thanks I have considered doing this but I apparantly live in the Bermuda Triangle & have trouble getting anyone to quote for work I want/need doing let alone actually getting someone to start!
I've considered doing it myself but I think its too big a job to do alone & I'm terrified of spiders.

I've heard mice under the floor before thanks to the filth the next door neighbour lives in, I've stopped them getting into the house but if I insulate under my floor will they make this their new home?? I'm also a bit worried if I do it myself I'll block the air flow, I know you shouldn't block the air bricks but can any crawl space be insulated??

mr mice says lovely rockwool to keep me warm

if you are doing a lot of work on the floor, consider taking up the old floorboards. Then you have good access and plenty of room to shovel up the rubbish, put wire mesh in mouse gaps, clear the airbricks, lay plenty of insulation, and lay a good WBP floor instead of the warped boards or soggy chipboard you currently have. You can put in an access hatch to replenish mouse bait through, and a floor safe or wine store while you are at it.

cabot said:

mr mice says lovely rockwool to keep me warm

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I thought that might be the case!! So I'm back to trying to solve the problem from above?

JohnD said:

if you are doing a lot of work on the floor, consider taking up the old floorboards. Then you have good access and plenty of room to shovel up the rubbish, put wire mesh in mouse gaps, clear the airbricks, lay plenty of insulation, and lay a good WBP floor instead of the warped boards or soggy chipboard you currently have. You can put in an access hatch to replenish mouse bait through, and a floor safe or wine store while you are at it.

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Wasn't planning any other work on the floor other than overlaying to resolve the vinyl movement/imprint problem. From what I saw when the floor in the bathroom was taken up last year there is nothing between the two houses, its as if we have a shared floor if that makes sense? I did put some poison under the floor through a handy hole before plugging it but the skank next door hasn't done anything about the infestation and doesn't think living in her own filth is a problem!
Although some of the boards in the hall have been chopped up a few too many times the rest of the floor is pretty sound, nothings wet or warped, its 22mm t&g (huge) sheets (not actual floorboards) and I've just remembered when I had a radiator moved we found most of the living room floor had a screed over it so there are no draughty gaps like I would expect to see with floorboards yet the floor still feels like ice and the screed is the other reason why I don't want to try & take the floor up myself; although a floor safe & wine store would be nice!