Wooden floorboards over concrete floor

[Christian McArdle]

I'd definitely put down the battens myself.

Christian.

[Set Square]

How much can you afford to raise the floor? You really need 2 x 2 battens - scribed to the floor to get them level, and with the floorboards nailed or screwed to them. But this will raise the level by about 2". If there is several inches of screed above the DP membrane (assuming there *is* one!) you could - with an angle grinder and SDS chisel (and lots of dust!) sink the battens into the screed, with the tops only just above the surface.

If this doesn't appeal, have you considered a floating hardwood (or engineered board) floor sitting on the concrete? The overall thickness of this would be about 15mm so, depending on the thickness of the existing tiles, the level may be similar to the current level. I used engineered board in my hallway, and it's fine. It's real wood - unlike laminated flooring - with a 4mm hardwood surface bonded onto a 10mm softwood base. It clicks/glues together in the same way as laminated. It uses a thin underlay, but the subfloor has to be pretty level to start with - so you may need some levelling compound if it isn't flat enough.

[Charlie]

Hi all,

Just need a bit of advice.

Our kitchen floor is currently tiled (badly) over a concrete base. I'd like to lift the tiles using my favourite tool (a large hammer and chisel), and then put reclaimed floorboards down.

Do I need to seal the concrete somehow? Should I level it out and with what (it doesn't look very level at the moment but this could be do to the crappy tiling)? Should I put down wooden battens so the floorboards aren't directly on the concrete?

Cheers

Charlie

[G&M]

This appeals to me if it works. But doesn't moisture collect in the thin layer between the floor and concrete and cause rot ?

[Set Square]

Not if the floor is basically dry - i.e. the concrete has a damp-proof layer in it. The underlay actually provides a further damp-proof layer - since it consists of a thin membrane with a thin layer of foam on top. Where strips of membrane/underlay join, there is an overlap with a self-adhesive strip on it.

This effectively takes care of *rising* damp. I suppose if you tried hard enough to slosh a lot of water on the floor, some could get underneath - but it would have to go round the edges of the room under the skirting, because the boards are glued tightly together.

[G&M]

I was thinking more of room moisture getting underneath and condensing on the cold concrete. It would be gradual but most damp is. Glueing the boards would certainly lower this risk.

What are best brands of engineered flooring ?

[Mark S.]

So say you laid a sheet dpm onto concrete with no dpm built in then floored over it where would any "damp" go?

Mark S.

[Paul Moore]

Charlie,

From the experience of my parents, I would advise against putting down a wooden floor in a kitchen.

They've had problems with damp from above. Also, you didn't specify what appliances you were planning to put in the kitchen. My parents' experience is that the sound of the dish washer and certainly the washing machine during the spin cycle is amplified by the wooden floor.

Good luck, Paul

[Set Square]

You are supposed to continue the sheet dpm for a couple of inches up the walls behind the skirting - so there's no possibility of damp getting to the wooden flooring. Having said that, I don't think I'd lay this type of flooring on concrete which *didn't* have a built-in dpm. I suppose older buildings may not have these, but it has been standard practice for many years now.

[Set Square]

If cost is no object, go for someone like Junckers [

]

However, many builders merchants sell cheaper products which are perfectly acceptable. I used a German product called Fertig-Parkett which I obtained from my local BM for about half the price of a similar Junckers product.

[Charlie]

I think this is the root of the problem. Although we had a chemical DPC injected into the walls in the kitchen, they didn't do anything with the floor. If I remove the tiles and have bare (porous) concrete with no damp proofing membrane or seal, surely if I lay wood of any kind it could get damp?

Thanks for all the helpful responses BTW.

Charlie

[Set Square]

If you don't mind raising the level, can can get "paint-on" dpc which you apply and then screed over. This would give you a surface on which you can put wood and, if you are careful with the screeding, will be good and level.

[Christian McArdle]

Why would you use a paint on type, when you could just lay plastic sheet? Does it need less screeding or something?

Christian.

[Set Square]

Potentially, because the paint-on stuff will bond with the sub-floor and with the screed - so the screed is not "holding the dpc down" in the way it would be with a plastic sheet.

[I should perhaps emphasise that these are my thoughts rather than a definitive statement of fact!]