ShareThisBy DWIGHT BARNETT
Sunday, November 19, 2006
Q: I was wondering if I could lay vinyl flooring on cement floor. Or do I need an underlayment before I lay down the squares?
A: Concrete floors can be prepared to receive an adhesive rather than installing an expensive underlayment.
Generally speaking, concrete floors have damp chalky surfaces that are not friendly to the adhesives used to install vinyl floor coverings. Concrete also has a high pH factor that is not suitable for most adhesives.
Some of the experts I talked with say the surface of the concrete needs to be cleaned and sealed before applying an adhesive. Others say a good cleaning alone will do the trick.
In my case I knew that there was a vapor barrier under the concrete floor to prevent moisture migration through the concrete. I allowed the floor to dry for one year with the home's air conditioning running during the warmer months to remove moisture.
I then simply swept the floor clean and applied a mastic floor adhesive and installed sheet vinyl. To date, I have not had any problems.
When moisture is present, however, the vinyl can discolor, curl at the seams or the adhesive can fail. Talk to your flooring dealer about the various mastics available for concrete floors and the precautions suggested by the manufacturers.
Peal-and-stick vinyl tiles will eventually fail unless the concrete is properly prepared. Use a mild solution of 1 part muriatic acid to 9 parts water to etch and prepare the concrete's surface.
Using a stiff brush, scrub the entire floor area with the solution.
Rinse thoroughly and then apply a solution of 1 cup of ammonia diluted in 1 gallon of clean water to reduce the pH in the concrete. Rinse again and let dry before applying the tiles.
Before using muriatic acid, be aware that the acid's fumes can be harmful to you and are strong enough to oxidize metals. Before cleaning the floor, make sure the work area is well ventilated.
Wear protective eyeglasses, rubber gloves and appropriate clothing before using household chemicals.
(Dwight Barnett is a certified master inspector with the American Society of Home Inspectors. Write to him with home improvement questions at C. Dwight Barnett, Evansville Courier & Press, P.O. Box 286, Evansville, Ind. 47702.)
