How long before installing hardwood on new concrete floor

We will soon be getting a new concrete floor in our house. It's going to be five or six inches thick.

We have been told that we will have to wait until the moisture content is below 0.3% (could have that number wrong) before installing a new hardwood floor. We have been advised to consider laminate instead that can go down after a couple of weeks.

I heard of a sealant that can be used to prevent any moisture reaching the hardwood floor. I was informed that the moisture would eventually escape up through the walls. Is this a viable option? I presume that the same is probably going to happen if we put down a laminate.

i was told to wait 3 months before putting down anything and you can see the floor cracks as it drys. I assume the issue would be would be that the wood will expand and then contract as it drys rather than it stopping the release of the moisture its self, hence you floor may twist

This thread on tiling onto a concrete floor deals with a lot of the issues involved and my last post in this thread gives a summary of the information and some relevant links.

There is more to laying a floor than trapping moisture in a slab as the measures you suggest would entail.

You must allow the wood to acclimatise to its surroundings before it can be laid.

The minimum good practice thickness would be 6" or 150mm concrete.

Make sure there is no pyrite in the hardcore substrate.


ONQ.

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All advice on AAM is remote from the situation and cannot be relied upon as a defence or support - in and of itself - should legal action be taken.
Competent legal and building professionals should be asked to advise in Real Life with rights to inspect and issue reports on the matters at hand.

I would wait at least six months after the heating is switched on. I would also store the wood in the house for at least four weeks before it's put down. I have experience of wooden floors coming up due expansion of wood. As a result, I went with a good quality laminate in my new house, but it never looked as good as the real thing. if you want to keep the dust down in the room while you wait the six months, paint the floor with PVA glue or a floor paint.

Mixing your concrete correctly to minimize over watering and laitence on the surface is best to reduce dust.

Alternatively the new concrete floor could be treated with a proven proprietary anti-dusting agent.

Be careful what you paint the floor with - some finishes can slow down the drying of the floor.

Another solution is to cover with an old carpet and regularly hoover to keep down the dust.


ONQ.

[broken link removed]

All advice on AAM is remote from the situation and cannot be relied upon as a defence or support - in and of itself - should legal action be taken.
Competent legal and building professionals should be asked to advise in Real Life with rights to inspect and issue reports on the matters at hand.

Hi, i am hoping to take up tiles and put down a levelling compound and then place a semi-solid wood floor over that. how long will i have to wait before i can place down the timber.

While 1mm per day is a rule of thumb for concrete, levelling compound may "go off" quicker.
Failing to prepare the surface after removing the ties may affect the compound.

Each product manufacturer may have different recommendations.
Do what it says on the tin to avail of any guarantee.

ONQ.

[broken link removed]

All advice on AAM is remote from the situation and cannot be relied upon as a defence or support - in and of itself - should legal action be taken.
Competent legal and building professionals should be asked to advise in Real Life with rights to inspect and issue reports on the matters at hand.

Comprehensive guide on installing hardwood flooring available [broken link removed].
Leo

Thanks Leo,

Couple of points on the built up construction shown below floor in this American publication.

The floor construction details show some things you seldom see in Ireland.

1. Polythene film as DPM under the slab - this is usually Radon Gas Membrane as required by most local authorities - check to be certain.

2. Fixing to slab - you see "floating floor" installations on a separating layer which allow for the greater degree of moisture variation and therefore movement in an Irish climate.

3. Figure 2. Battens on mastic below polythene in an unventilated space could invited disaster. Timber needs to be pressure treated, kept ventilated or placed to allow moisture vapour to escape.

4. Figure 3. Not familiar with breathing paper or felt used as moisture retarder. Felt is water proof, not vapour proof, while Irish breather paper is used for one way transpiration of water vapour through a timber frame.

Happy to stand corrected on all of the above.

As for the setting out and fitting techniques in the manual, apart from the metric measurements they seem reasonable. Good luck finding a straight wall or square rooms in a Celtic Tiger spec house though...

ONQ.

[broken link removed]

All advice on AAM is remote from the situation and cannot be relied upon as a defence or support - in and of itself - should legal action be taken.
Competent legal and building professionals should be asked to advise in Real Life with rights to inspect and issue reports on the matters at hand.

Good points ONQ. The advice on checking for moisture content and aclimatisation should be universal.
Leo