The Floor Beneath You

Why Installing Hardwood Flooring Over Concrete Slabs Is So Risky

If you have a concrete slab in your home and want to install hardwood flooring, installing it over the concrete carries some risks that you need to address before any work can be done. Some types of wood are not suitable for being installed over concrete because of the potential for moisture damage. However, there are always solutions, and in this case, those solutions include using a different type of wood or installing a very good moisture barrier.

Concrete Has Moisture, and That Will Swell Wood or Worse

Concrete floors actually have some moisture in them, and that moisture can rise up. It may not appear as a liquid to you, but it is there. Similar to how humidity in the air doesn't look like liquid, but you can tell it's there. That moisture can soak into the hardwood flooring. Again, this is as humidity and not actual liquid leaking out. This will cause the wood to swell, crack, or cup. All of those problems basically ruin your floor.

Engineered Hardwood and Thinner Non-Engineered Wood Can Be Exceptions

Engineered hardwood doesn't expand or contract like thick solid hardwood can. That makes engineered hardwood flooring a better choice if you want it installed on top of concrete. Sometimes you'll find companies that will install thinner solid hardwood over concrete as the expansion and contraction should be less intense, but that wood will still show some of those effects. If you want hardwood over concrete, engineered is best; if you want solid hardwood over concrete, then you'll need to look at some additional steps to control the moisture rising up from the concrete.

Floating Isn't the Answer, but a Moisture Barrier May Hold the Key

Sometimes flooring is floated over the subfloor, and at first, this sounds like a solution to the moisture problem if you want a thicker hardwood floor over concrete. But solid hardwood can't be floated. Engineered hardwood can, but that's already OK to install over concrete. However, you may still be able to install solid hardwood over concrete if you install a good moisture barrier. In a nutshell, this is a plastic sheet that is placed over the entire slab and sealed at all ends, trapping any moisture in the concrete and preventing it from rising up into the wood. Don't try to do this yourself, though; while the barrier is a plastic sheet, it's not just random plastic. A flooring installation company will have the right materials.

For more information, reach out to a hardwood floor installation service, such as Larry Helms Floor Sanding & Refinishing Inc, near you.