Choosing appropriate flooring is difficult enough without the problems that come with finding floors for a basement complicating things even further. The biggest issue in almost any basement is, of course, unwanted moisture. Moisture seeps in from below through the concrete and has the power to weaken the bond of the adhesive used for floors or tiles, to make hardwood floors buckle and warp and to make carpets acquire that elusive basement smell caused by mold growing below the soft veneer.
Before you go dreaming up designs and making plans for your basement, check to make sure that your floor is suitable for such installations. Take a sheet of impermeable material that is about 3’x3’ big, like a trash bag, for example, and lay it flat on the basement floor, sealing it with tape on all four sides to make sure that no air gets in. Do this in a couple corners and areas by walls as well as in the center of the room. Leave it there for at least a full 24 hours and then check under the bags to see if moisture has accumulated.
If it is damp under the bag, then you have a moisture problem that needs to be resolved before you proceed. Depending on the source and extent of moisture, there are solutions that range from the simple to the annoying. This is a whole separate beast covered in other articles.
So, let’s pretend like in this particular Choose Your Own Adventure novel you turned to the page that cheerily informed you that your basement is dry. Now you can begin to think of your different flooring options.
The main floor coverings available are carpet, hardwood floor, engineered hardwood floor, laminate floor, ceramic and porcelain tile and cement.
In general, carpeting, hardwood floor and laminate floor are not recommended for basements. Variations in humidity, which are common in basements, warp hardwood and laminate floors and encourage mold growth in carpets. Even basements that are treated for moisture related problems can have seasonal trouble with moisture or during excessive rain. Exceptional events can have long-term effects that will leave the floor warped or ruined. If you insist on installing one of the above floors in your basement, take some precautions, like the installation of a vapor guard under the floor. A durable and high density polyethylene sheet with 3/8” tall dimples creates air space between the flooring and the cement slab, trapping any moisture and preventing it from traveling up to the surface of your newly installed floor.
Engineered floor is an excellent alternative to hardwood floor in the basement. Engineered floor is flooring constructed from three to five layers of different hardwood materials with either a hardwood or high density fiberboard core. Because of the layered construction, engineered floor has a higher resiliency to humidity changes that keeps it looking good even in finicky basements. Additionally, engineered floors are thinner, so you can add extra insulation and they have a real hardwood floor layer at the surface, so you can pick the look you want just as you would when sifting through solid hardwood floor.
Another option is laminate floor. Laminate floors are composed of a moisture resistant wood based core, a backing, and a resin based melamine or aluminum oxide decorative surface with a clear layer of aluminum oxide, like a finish on traditional hardwood floors, which strengthens the surface and protects against staining and scratching. Laminate floors are floating floors, meaning they are not attached directly to the sub floor, which makes installation directly on the concrete or putting a vapor guard down easier. Most laminates should be fine to use in basements but when looking at laminate check to make sure the manufacturer does not advise against it, as is the case with certain laminates. Make sure you do the moisture tests, because when laminates do buckle they are difficult to fix.
If you’ve determined that your basement is sufficiently dry and moisture tests have shown the floor to be consistently dry, you may also want to consider ceramic or porcelain tile. The tiles can be installed directly on the cement floor, a durable and good sub floor for tiling (or as a precaution, try installing 2 by 4 inch sleepers, cover with plastic and put in plywood to be used as the sub floor). Check for cracks, which are bad in general and should be fixed before any basement remodeling project ensues, but especially for ceramic tile, as cracks in the cement will actually fracture the tiles at the surface.
Finally, the easiest alternative to more traditional flooring options is painting or staining the cement sub floor that is present in most basements. You have a lot of flexibility with color schemes and any problems that may develop in the floor will remain visible, instead of festering under layers of padding and floors. It is easy to insulate the cold cement floor with a thick throw rug.
No matter which route you choose for your basement floor, below ground installations require that you be especially meticulous in preparing the sub floor for installation and making sure that the space as a whole is suitable for your uses. Get a professional to check your basement’s usability and to recommend a course of action for making it usable if it doesn’t seem to be at first. It may be worth the extra investment, as it would be a shame if your newly renovated basement began to creak, buckle and smell from the mold right after you finished it.