Another "cold spot" question

Snakey

My lovely new (new-to-me, it's 1950's) flat has half of one bedroom, the end of the hallway, and half the bathroom, located above fresh air. This makes the floor absolutely freezing in the winter, as I have recently discovered, and makes those rooms cold as a knock-on effect. The building is listed and so insulating from underneath is not possible.

Do I have any options, other than just putting up with it? Is it even possible to insulate a floor from inside? And how big would the level change be?

(I also have the communal stairwell and a lift shaft, both of which are more or less open to the elements, adjacent to these same three rooms, but at least walls are "straightforward" in the sense that I know it's possible to put up cladding/insulation - although you wouldn't then be able to close the bathroom door so it will need some thought!)

I cannot afford to do any major works right now, but it would be nice to know whether I might be able to do something one day or whether I just have to put up with it.

bridgedino

If there's floorboards you could lift them, place insulating slabs between the floor joist then re lay the floor boards

lee111s

Underfloor heating? Extra thick/insulating underlay? Insulation under the floorboards?

OliveOyl_2

In our bungalow, one bedroom has three outside walls and is North facing. The man in our carpet shop recommended a hefty underlay (it looked like rigid felt about 5mm thick) and it improved the warmth of the room hugely. Because of the old fashioned door threshold we didn't need to shave the bottom of the door, but in another room the carpet fitter (for a charge) brought something (I didn't see it) that shaved the bottom of the door without taking it off.

Robwiz

You could lift the floorboards and fill the void with mineral wool insulation. This would be most effective in cutting heat losses through your floor. Then fill all the cracks between the boards.

Thick underlays and carpets would also be effective insulators. But as it's a listed building, it's certainly worth going all round the room hunting down draughts – around the windows and doors, the skirting boards and the wall/ceiling junction plus the light switches and electrical sockets and anywhere cables come in from outside (phone/TV aerial).

Snakey

Thanks all. I have concrete floors, no floorboards (I haven't lifted the carpets, but I did view a similar flat and the floor was made of solid black stuff). The guy in the carpet shop showed me some underlay which was about 1cm thick and apparently is normally used when noise insulation is a requirement. He said that would help with warmth insulation too. Unfortunately just a few days later I started to have some issues at work which meant I had to put a hold on my refurbishment plans (and I have since lost my job) so I never got to get proper quotes or anything. But if that alone might go some way towards solving the problem that would be ideal.

I want to get doors replaced when I have the cash as well, because it looks like the old tenants had domestic violence issues and most of the doors have punch-marks/fillings in them and are hard to open and close as they've clearly been knocked out of true at some point, but it's handy to know that it is possible to shorten them without having to replace them so that I wouldn't have to do everything at once.

Rob - I also have single-glazed crittal windows. It'd be harder to find the warm spots in my home than the cold ones! But I knew all this when I moved in, I'm not complaining (well, only a bit) so much as trying to find straightforward, reasonably-priced solutions for when I have the cash. Was hoping to have it done by now, but these things happen.

Robwiz

Snakey - you probably already know this but heavy curtains are effective in reducing the heat losses from single glazed windows. Shutters and secondary glazing are too, and all three in combination are even better. This Historic Scotland report gives the full details.

Mrs_Imp

Wickes has a range of insulation at different prices. You will end up with a step in to the rooms, but you can do the laying of the insulation yourself. http://www.wickes.co.uk/Products/Building-Materials/Insulation/Insulation-Boards/c/1000272

eta: I've just noticed that it's a listed building. Check with your planners before doing anything. It's always best to be safe, and they might know of suitable products, or if there are any grants available to you.