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. By: Rich Binsacca