Some of the best basement flooring options are cork floating floors.

There are significant differences between above and below grade flooring installations. Cement foundations below grade can have slight yet continuous water vapour (moisture) due to evaporation. This moisture can get trapped and accumulate under flooring causing mold and mildew to form and floors to fail.

Whether below, at, or above grade, proper moisture testing should be done prior to any flooring installation. All flooring professionals should offer this service with an installation package but many DIY homeowners or handyman may have little knowledge of these basic requirements. If problems arise, all warranties are void without proof of proper moisture tests before, during and after installation.

The adhesives required to install cork flooring are extremely sensitive to moisture – especially in a cement slab. Hydrostatic pressure must be less than 3lbs/1000sf in 24 hours. By industry standards, this is ranked as “very sensitive”. For the uninitiated, most other forms of glue-down or mortar-in-place floors can accept 5-8lbs/1000sf in 24 hours before special measures must be taken. “Unsealed” basements often sit between 5-10 lbs/1000sf in 24 hours. Even “sealed slabs” can still exhibit hydrostatic pressure above 3 lbs/1000sf in 24 hours. .

It is for this reason a cork floating floor is the best flooring option for a basement. It is also hightly recommended to use a moisture/vapour resistant cork underlayment even when the concrete has a moisture barrier incorporated into the slab. A standard vapour barrier is 6mm polyethylene sheeting with 8” seam overlap, sealed with a moisture resistant tape, and the basement is ready to install a new floor. Moisture testing must still be obtained and documented after complete installation of vapour barrier and flooring.

Cork underlay is a solid, non-compressible material offering an excellent option for your flooring. It will increase the R-Value of the basement and offers an easy, affordable “floor raise” if the cork is going to butt up against another floor. Forna’s cork floor is just a little less than ½ inch in height whereas ceramic tiled floor for example can be up to 3/4″. Cork underlay is an easy way to add an extra 1/8 inch o1/4 inch of height so the cork floating flooring can be smoothly lined up with an existing floor.

When it comes to the best basement flooring, the simplest approach is sometimes the best. Some customers have tried installing a subfloor in order to use glue-down cork tiles instead of floating floor option without knowing a vapour barrier is still requred. This makes for a costly and time consuming process and may still not be warranty worthy. If a glue-down flooring product is exposed to excessive moisture from underneath is very likely to fail, in some cases in a matter of months. There is also the option of using click-together subfloor products but they are often composed of OSB board which is not recommended for glue-down flooring. Therefore, another subflooring product would be needed making another costly scenario considering it would also still need a moisture barrier underneath it all. The higher cost of materials and increased labour required for proper installation does not add up to value or product satisfaction.

Polyethylene sheeting is an adequate moisture barrier for as little as $0.06/sf at home renovation stores. Forna Cork Underlay is an ideal support product for any flooring product available in 3mm, or 6mm or even 12mm for special situations. Many colors and styles of Forna cork floating floors are available that range in price from cost effect Golden Beach to our high-end Logan. Even with the cost of proper moisture testing, this is arguably the most affordable approach to basement flooring installation.