Can I Put Hardwood Floors on a Slab of Concrete?
If your home is built on a slab rather than a crawlspace, your options for flooring change slightly. Installing hardwood floors over a slab concrete floor will take some of the right concrete slabs, properly cured, in the right conditions. Excess moisture is a tremendous risk in this install and can ruin a project no matter how much care you take.
Preparing the Concrete
Your concrete slab, once cured, will need
- to be leveled. This may include grinding the surface and filling it in
- a sealant
If the floor is below grade you will also need:
- a vapor barrier
- a plywood or planking subfloor
Skipping any of these steps could result in a ruined floor in the event of a leak or seepage from beneath the concrete.
Once your hardwood flooring is delivered to the space, it will need to acclimate. Every space is different and has a different moisture level. Depending on the moisture level in your space, you may be limited as to the thickness of your hardwood floor choice.
Once you’ve installed the sealant, moisture barriers and subfloor you must determine your method of application. While some hardwoods can be nailed into the subfloor, others can be glued. While it is possible to glue some hardwoods, such as parquet flooring, directly to concrete, it should never be applied below grade.
Engineered hardwood floors can be easier to install and may survive below-grade conditions better than real hardwood products. However, if you’re installing engineered hardwoods directly to the slab, the slab must be both perfectly smooth and perfectly level. Moisture protection should also be used because even engineered wood will expand and contract due to humidity.
Concrete Cure Time
If you’re applying hardwood over a brand new slab, be sure that the slab is fully enclosed and has had at least 60 days to cure. Without this cure time, you’re at risk for moisture build-up under your new hardwood installation, which may lead to mold and can ruin your hardwood floors from beneath.
Stay Above Grade
Concrete slab on grade installations offers homeowners the best option for a dry hardwood floor. Manufactured hardwood floor products are a better option for basements. Make sure to have the concrete leveled and sealed against moisture before installation.
Hardwood floor products can be found that will work well over concrete, but you will need to allow the concrete to cure and make sure that it is level and smooth. In addition, the concrete will need to be sealed to avoid moisture seepage under your new floor.