Hardwood Flooring On Concrete Sub-floor

Question: I have just added an addition to my home. The floor is a concrete slab and I want to install glue down hardwood flooring over the concrete. I have been told that the concrete needs to cure for at least 30 days before I can install the hardwood flooring. Is this right?

Answer: One of the most common errors with hardwood (which is what parquet is) is not to let it acclimatize (acclimation) to the room its being placed in. This requires 48 to 72 hours. The boxes need to be opened so that the air in the room can get around the wood. Most warehouses are very dry, the wood will suck moisture from the air in your home and expand and when it expands, if it has nowhere to go it buckles. Another error is to place the parquet tight against the wall, there should be 3/8" to 1/2" gap between the edge of the parquet and the wall (for expansion).

The concrete does take time to cure before you can install the hardwood flooring. I would suggest that 30 days is not long enough. My recommendation would be a minimum of 60 days and 90 days would be better.

You can test the concrete to see if it has cured to a point where you can install the glue down hardwood flooring.

Use some duct tape to tape down a number of pieces of poly film, 24" square, on the concrete slab in different locations. Allow the poly film to remain in position for 2 full days. Remove the poly film and if you have condensation under the poly film or the concrete has turned a different color, the concrete has not cured to a point where you can install the glue down hardwood flooring.

You should also be aware that standard concrete sealers should not be used when installing glue down hardwood flooring. The standard concrete sealers may prevent the glue from adhering to the concrete. Concrete sealers, specially formulated for glue down hardwood flooring, are now available from manufacturers.

Flooring - Hardwood

Hardwood Flooring On Concrete Sub-floor

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