cold cold floor brrr help

happyhero

Hi can you help. We are really cold in our lounge even though the rad is really hot. The floor is ice cold, well not ice, but very cold. I have a laser gun thingy that you point at things and it gives you an accurate temperature reading not that I needed that to tell that the floor was bloody freezing but it helps to work out whats going on, eg cold spots etc.

Anyway I have a 1930's house with a floor space of about 18" underneath. The floor is pine floorboards (not T&G) and there are air bricks at the front and back and side of the house. Although I know the temptation is to block these airbricks I have also read many times about the damage that can cause as they are there for a reason.

The floor varies in the lounge from about 6 degrees to 13 which does feel cold, depending how near you are to the rad for example. It's almost like having the reverse of a heated floor, a chilled floor, fighting what our rad tries to do.

I have used black silicon in the cracks and under the skirting but this doesn't help the fact that the floor is so cold.

Any recommendations?

We are thinking of having the floor carpeted in the future (got a rug at present) despite the nice floorboards but I think the cold will come through the carpet, after all carpet doesn't seal. I was wondering about putting, for example, that 7mm green stuff you get for laminate and then putting sheets of ply on top to give a new insulated floor before carpeting, but am I going to far or doing something silly? Obviously the floor will get a bit thick if I go too mad.

I am worried about anything I do not causing the timber floor to sweat etc.

Any other suggestions?

Any help appreciated?

sarahlouise210

We have the same age house ... we were advised that a really good underlay under the carpet would do the trick ...doing it in January!

jennifernil

Our floor is not as old as yours, but we have it insulated with 10cm of Rockwool underneath , and we have underlay and carpet on top. It is really cosy, our CH went off 3 hours ago but I am sitting here typing with my bare feet on the carpet and my feet are nice and warm. If you can get to the underneath of the floor it may be possible to insulate it from below with something like "Kingspan".

tonyp2020

Hi, you can fit a carpet and underlay. If you position the edge gripper rods about 30mm from the skirting boards and then turn the carpet under at the edges then that will stop most of the draughts. A Carpet Fitter might be able to give more information.

You could also use filler foam to seal the gaps between the shirting boards, floorboards and wall. This requires a very even application of filler foam, using a small extension tube/nozzle.
This will help keep the draughts down, and will also reduce the number of spiders getting into the room. Let the foam set and then cut the excess foam(using a long flexible knife, like a bread knife) flush with the skirting board.

If you want to keep the floorboards because you like the look of them, then another answer is to insulate under the floorboards. As bit like insulating the loft, but upside-down.

You could fit 50mm thick insulating slabs, called "batts", under the floorboards. These slabs (they are quite firm and don’t bend easily) are 50mm thick by 400mm wide by 1200mm long.

Very briefly, as this is not an easy process to describe, you need to lift every 5th floorboard (without damaging them, which is not easy).
Don't lift a floorboard directly running parallel with the skirting board, but the next one out. It will need working out exactly which floorboards need lifting, you might have to lift every 4th in places.

Then you need to use green garden netting, cut as wide as a floorboard, to support each batt at both ends and in the middle.

Each batt is 1200mm long and 400mm wide. The floorboards/joists spacing will be in imperial (feet/inches), while the insulation is in metric.
The width might need trimming to suit the gap between the joists, but make the batt 12mm wider than the gap between the joists, to help it stay in place.
The length of the batts might need trimming as the joins need to be under a removed floorboard and supported by netting.

The technique is to hang the netting loosely across the joists, the insulation is placed beneath the floor and pushed into place, ensuring a good close fit, then the netting is pulled tight to stop the insulation dropping.
Sounds easy? It's not, but it works well.
50mm insulation will still expose at least 50% of the joist to the air (to make sure that it can dry out if it gets wet), although the amount of floorboard exposed to air if a carpet is fitted is almost nil.
HTH's
Tony

roswell

Go to your local flooring / diy shop and look for some green insulation boards there about £20 for 20 square meters these are excellent for carpet / wood / laminate flooring.

another option but will propbably cost the same is to lay hard board over the floor boards before relaying the carpet.