By: Rich Binsacca
Published: December 13, 2009 on houselogic.com
When it comes to basements, lots of detail is put in the roofing and walls to ensure they’re in top shape and are structurally sound but less attention is put into the floor. Owners always install things like sheet piles to provide earth retention and excavation support (keep an eye out for sheet pile sales from Sheet Piling UK if you need to improve the strength of your underground structure) but tend to ignore the floor. Many people think that they can put any floor in their basement and it will last a long time and keep strong but this isn’t true. Keeping your basement dry and free of condensation is key to installing the basement flooring of your choice.
Moisture and humidity
Because the floor of your basement is below grade and the lowest surface within your house, it requires special considerations before flooring can be installed. If your basement has ever been susceptible to water infiltration and flooding, those problems must be remedied before flooring is installed. Sealing your basement from water and moisture infiltration can cost from several hundred dollars to a few thousand dollars or more.
Humidity and condensation are other concerns. Because moist, humid air is heavy, it tends to sink to the lowest part of your house-your basement. There, warm, humid air can come in contact with relatively cool surfaces, such as a concrete slab floor, and condense. Keeping condensation in check during warm, humid months helps ensure that flooring remains stable and free from mold and mildew growth.
Most likely, your existing heating and cooling system is equipped with a dehumidifier that maintains relative humidity (RH) levels between 30% and 60%, which the Environmental Protection Agency (EPA) and building codes recommend for a healthy indoor environment. A portable, plug-in unit for single-room use costs about $200 and includes a monitor to regulate the RH level.
Level floor surfaces
It’s also critical to inspect your existing concrete basement floor and make adjustments for any noticeable slopes or flaws that might damage the new floor finish or affect its aesthetic appeal.
Patch or fill minor cracks and flaws with an elastomeric sealant made especially for concrete. A 10-ounce tube runs from about $4 to $10 at home improvement centers.
Use a 3-foot or longer bubble level to see if any sections of the floor slope more than a half-inch in 8 feet. Fill in low spots with a self-leveling compound, available at home improvement centers for about $30 for a 50-pound bag. For about $60 to $80 per day, rent a concrete sander to reduce high spots.