Laying new oak floor

[Mark]

I'm planning on laying a t&g oak floor.

The existing floor is concrete and not particulary smooth.

I'm doing my homework first to establish the correct procedure. Is it similar to laminated flooring with a dpc membrane and soft underlay boards? Is it normal to glue the boards to each other?

Advice sought.

mark

[Grunff]

While it is possible to lay an oak floor as a glued floating floor, it is not recommended. This is because while laminate behaves in a uniform way in response to humidity changes, oak expands and contracts non-uniformly. Depending on how your oak has been sawn, the stresses in a floating oak floor may result in it coming apart over time.

There are 3 recommended methods for laying an oak floor on concrete:

1. Battens, then secret nailing. This is simple, reliable and always works. Putting down the battens takes a bit of time, but once they're down, the nailing is pretty quick (with the correct nailer that is).
2. Double sided adhesive underlay. This is like a 3mm thick stretchy underlay, with adhesive both sides. You stick the underlay to the floor, then stick the oak to the underlay. This only works if you have a smooth, dust-free concrete floor.
3. Instead of using battens, you use lines of special rubbery glue. You apply these at 30cm spacing, and lay your oak floor onto the glue lines. The glue remains flexible, allowing movement in the oak floor. This method can be used on more uneven floors, but the concrete still needs to be dust free, so you may need to seal it.

For my money, I'd batten with 50 or 75mm battens, and insulate between the battens with kingspan.

[Mark]

Thanks for this Grunff.

I actually sealed the floor today with diluted PVA as I was fed up with constantly dust-busting.

Option 1: I did wonder about this but was concerned about the height rise. What do you think is the minimum thickness of batten I could get away with? Are the battens placed loose on the concrete?

Option 2 is out, it's not a smooth screeded floor. Option 3: Any idea where I might get such a glue?

mark

[Andy Hall]

FWIW...

I have some oak flooring on concrete where method 1 was done. This is in a relatively modern house (1980s) where the floor is both screeded and insulated in the concrete already. Therefore Kingspan wasn't needed, but I think could be interesting where the floor is not insulated.

The battens are 50x25 nominal and are fitted to the floor with plugs and screws. Then the boards are secret nailed. I am doubtful that one could get away with much less thickness than that. The floors have been in place for about six years and are perfectly fine.

Obviously if the floor is uneven, one would need to pack the battens to bring them level in both directions and avoid them undulating.

[Grunff]

Very sensible :-)

I think 20-25mm is the absolute minimum. The oak will add another 18/19mm.

No, you need to plug + screw the battens down, every 40cm or so.

Lots of places, most places that sell hardwood floors do it. It looks like this:

[stevelup]

minute. I did one small area using the self adhesive underlay and found it to be a complete pain in the proverbial. There is obviously a knack to using the stuff but I didn't get it even after 10 square metres of floor was down. One mistake and you are shafted too - the stuff grabs instantly and there is absolutely no way of repositioning something once you have gone wrong.

I'm very interested in the glue you mentioned and have visited the URL above. Have you (or anyone else) any first hand experience of laying a floor using this system? I'd be interested in hearing more about it.

Many thanks,

Steve

[Grunff]

I've watched it being used, and it looked like a fairly fast way of laying floors. I haven't used it myself, because I like battens :-)

[Andy Hall]

Gluing is a bad idea for this. If it goes wrong, you have no real backout.

The batten method is far safer.

[Mark]

Thanks for all the advice. It's battens for me!

mark