Can You Put a Floating Deck on Top of Concrete?

Flat Floor

• Before you can install floating floors on top of any surface, the only basic requirement is that the area be completely flat. The nature of concrete is that it tends to self-level. While you can slope concrete by troweling it during the curing process as it begins to harden, "flat" is different from "level." Flat is merely a surface that has no dips and valleys in it, while level indicates that the floor has achieved a horizontal surface of equal, even plane, such as water in a glass on a sloped table. The water will always be level, even if the glass is tilted on top of a flat table surface that isn't level.

Good Repair

• The slab needs to be in good working condition before you install a floating floor on top of it, or there could be issues down the road. For example, if the slab is crumbling in an area, it needs to be repaired before you put the floor in place. Otherwise, the depression in the slab as the crumbling pulverizes into dust causes a depression in the floating floor as well.

Moisture Barrier

• Perhaps one of the most important elements to building a floating floor on top of a concrete slab is the inclusion of a moisture barrier. This is generally a layer of plastic sheeting or felt paper. Concrete breathes, which means it inhales and exhales moisture. When you trap that moisture with a floating floor, it causes damage to the underside of the floor unless a moisture barrier is in place.

Padding

• Padding is optional in some cases but mandatory in others. The padding should always be installed on top of the moisture barrier. The type of floating floor you are installing determines whether or not you use padding. It can be put on top of the moisture barrier to help cushion the floating floor for areas with heavy foot traffic. It also helps reduce noise.