Boarding a floor

I did this all wrong. I used hardboard, nailed to the boards as you suggest. It must be something to do with relative expansion coefficients, but the hardboard developed "bubbles" at times of the year and lifted the carpet up with it - you couldn't see anything but it gave a very strange feeling to walk on..

I live in an old (c 1680) house with solid stone walls and no foundations or dpc - which could have been the cause. The floorboards were very worn in places, with gaps that you could see through. I asked a builder and he said that, whilst the whole lot was safe, the floor would have to be replaced. The cost would have been .. a lot.

I replaced it with ply, not nailed down, but floating. I used a Wolf dovetailer to dovetail the edges and "jgsaw" them together into one single floating piece and glued the joints. I laid the assembly on a heavy-duty poly sheet - to stop the draughts coming up from the cellars, directly underneath. It hasn't given me any problems at all in many years.

I wouldn't say that was the right way to do it. But it seems to have worked.

If you use hardboard, soak it (I have used a very wide emulsion brush to apply water at ¾ pint per 16 sq ft )before nailing,allow it to stretch (48 hours laid flat in the room the board is to be laid in)then nail it down it will dry out drum tight, mind you profesional floor layers seem to use thin ply (eigth inch?)

Thanks for all the tips and advise. I'm off to B&Q tomorrow :)

ken

Is t+g chip board still used? Did my kitchen a few years ago in the same manner as my parents house. T+G chip board over polystyrene over plastic membrane. Made the room warmer and the floor quieter. Also eliminated sound coming from the flat below, and doubtless reduced noise travelling down too.