Laying solid wood floor on concrete sub-floor

[Bill Carr]

I may soon be getting some of this http://www.wickes.co.uk/Solid-Wood-Flooring/invt/1... to lay in my lounge, which has a concrete sub-floor.

What advice can PH-ers offer regarding fitting? Should I use un underlay e.g. http://www.wickes.co.uk/High-Performance-Underlay/... and lay the boards on top as a floating floor? Or should I discard the underlay, seal the concrete using diluted PVA (or another substance) and nail the boards directly to the concrete, using PVA for the tongue and grooves?

All advice appreciated!

[T5GRF]

We had lots of problems with our solid oak floor laid onto a membrane and fibre board base. The idiot fitter laid it as a "floating floor" and as the moisture content in the concrete was so high the floor warped very badly causing huge damage to the floor and decoration including ripping off skirting cutting cables etc. As is often sadly my experience with using our friends in the building trade the complete bernie blunt that laid it when faced with the awful results of his incompetence and the circa £10k bill to rectify promptly went bust.

Read the makers instructions carefully, should it be floating or secret nailed? Make sure the wood is left in the room it is to be laid in for a few weeks prior to fitting to help it acclimatise to the conditions too.

Good luck real wood looks so nice when it is laid properly

[Rich135]

Get a hydrometer and check the relative humidity of your concrete first - needs to be below 75% as a minimum.

I cannot stress this enough!!

[V12Les]

Dehumidifier in said room till it draws no more water. Leave for a few days then place flooring in the room, dont stack on top of each other tho.

[Tony 1234]

You can of course stick the woodfloor to the concrete using a special adheasive (which is very expensive)

[Bill Carr]

The concrete is 12 months old now so would humidity/water content still be an issue? It has had carpet laid (and underlay) on it for the past year.

[TonyHetherington]

While not even remotely close to what you asked, I Thought I'd just mention that we just did laminate in our lounge/dining room and bought from this place - very good and highly recommend, and over the moon with the quality of the product;
http://www.flooring2floors.co.uk/

[V12Les]

Bill Carr said:

The concrete is 12 months old now so would humidity/water content still be an issue? It has had carpet laid (and underlay) on it for the past year.

Should be fine then. I'd still leave uncovered for a week or so then place flooring in small stacks in the room. Any doubt then just hire a dehumidifer for a day and see if it draws any water out.

[Bill Carr]

Cheers chaps.

Any thoughts on floating floor vs straight laying? Or is it dependent on the makers instructions? Only problem with that is the flooring is 2nd hand and probably doesn't still have instructions...

[rsv gone!]

If you want to protect from damp then put a couple of layers of 100 gauge polythene sheet down and tape the joints. Dress this up behind the skirtings for maximum effectiveness. Put the underlay foam down and then lay the flooring. New skirtings to cover the expansion gaps that you've left around the perimeters.

[V12Les]

For concrete i'd use underlay. Slightest bit of grit underneith will drive you nuts, plus it allowes for better movement of the boards and adds a bit of sound obsorsion.

[Tony 1234]

V12Les said:

For concrete i'd use underlay. Slightest bit of grit underneith will drive you nuts, plus it allowes for better movement of the boards and adds a bit of sound obsorsion.

I don't like the hollow sound a floating floor makes when walked on, we have had solid wood stuck down to concreate now for 5 years and it's still as good as the day it was laid (and silent)

Most in the trade regard Floating floors on concreate as "Jo Bloggs" DIY

[dilbert]

Not that this is that, but I have a feeling that a proper Parquet floor is laid on bitumen.

[rsv gone!]

dilbert said:

Not that this is that, but I have a feeling that a proper Parquet floor is laid on bitumen.

It often is.

And often the bitumen is the only damp proof membrane (as my employers have found out through bitter experience).

[russ_a]

We had a new Walnut floor layed on concrete (probably about a week after it was put down IIRC) and used a special flooring adhesive. Cost over £100 a tub and it means the floor can never be taken up but it did the job and saves a few £££ on labour when laying.

[stig of the dump]

You can lay the floor in a number of ways - either stick the boards to the concrete floor using a glue called laycol 54 I think the floor will need leveling.

Alternativly the most recent way I have fitted is by laying a foam underlay with membrane (from screwfix) then plywood over fixed to the concrete floor with gripfill in small areas. Then fixing the floor to the ply with an adhesive called ceriset? p60 or p70 (also from screwfix). Finally gluing the tounges with pva and then secret nailing with a air nailer.

[Gas Monkey]

I glued mine to the sealed concrete floor using this stuff.
Styccobond B92, solvent based, recommended for oak.



Supplied by Betrex(.co.uk) Ltd, Birmingham.

Was £39.99 +vat for a 15kg drum, much cheaper than any other supplier I could find.

It is like a drum full of runny grip fill !

Edited by Gas Monkey on Thursday 26th November 20:06

[very numb]

I laid all 40m squared of mine myself with the help of a friend. Walnut onto concrete - laid this plastic sheeting sorry, membrain, down and then these green square fibre boards. Has been fine, well over 12 months and looks brilliant. Trouble is the bloody dog and OH's heels!!!

Way i was told is to remove the skirting and put the flooring up against the wall but leave a gap between the flooring and the wall to give the flooring some room to expand and contract. Then put new skirting on top of the flooring.

We linked 3 rooms together with no seperators which we were told NOT to do incase any part had to be pulled up - you could do a room at a time whereas now the whole lot would have to come up should it get water damaged etc. But it looks soo much better this way without any seperators.

It is surprisingly easy to lay your self, the hard parts are the hallways and radiators.

[WWESTY]

Are you sure the concrete floor is level??


Any variations will play havoc with your wood flooring.

[Bill Carr]

Thanks for the useful tips chaps. It's interesting to read all the alternate views.

Unfortunately, I've no idea just how level the concrete is - it's currently masked by carpet and underlay. It could be "ok" or it could be a bit of a state, I have no idea.

Assuming (hoho!) it is ok, can I get away with putting the boards straight on to a 3mm insulation membrane jobby?