Can You Cover a Concrete Floor With Carpet?

Testing the Concrete

• Before installing carpet on a concrete floor, you must test the moisture level and the alkalinity of the concrete. If the pH and moisture levels are high, mold and mildew can form under the carpeting. Besides the mold and mildew, the carpet adhesive, if used, can degrade over time. Use a testing kit from the carpet dealer to test the concrete. You will need to test the concrete over a period of 60 to 72 hours for accurate results. The kit is called a calcium chloride moisture testing kit. Talk with the carpet dealer to determine the acceptable moisture and alkalinity levels for the specific carpet and pad that you choose to install. Generally, urethane-foam bonded carpet pads are recommended for use over concrete because they have a moisture barrier.

Temperature for Installation

• The humidity and temperature in the area where you will install carpeting over concrete must be between 65 and 95 degrees Fahrenheit, with a relative humidity level of 10 to 65 percent. After the installation of carpet on concrete, the temperature must not drop below 55 degrees Fahrenheit. Using a dehumidifier and heating vents in the basement or garage are remedies for high humidity and temperature control.

Preparing the Floor

• Before laying the carpeting over concrete, fill in or repair any cracks and holes. Sweep floors so there is no dust or dirt debris on the floor that would prevent any adhesive from sticking to the floor. If floors are dirty, use a damp mop to clean the floor at least one week before performing moisture and alkalinity tests.

Adhesive Methods

• Installing carpet over concrete is done using tack strips or adhesive. If you're using tack strips, you'll need to nail the strips to the concrete floor with concrete nails. Adhesive is another method for installing carpeting over concrete. The adhesive comes in spray form or in a bucket for applying to the floor with a trowel. After laying carpet with adhesive, you'll need to stay off the carpet for at least 24 hours to give the glue time to dry.