How to Apply an Acid-Stain Look to Concrete Flooring

Acid stains were used commonly in the past, but they are not environmentally safe. They have been almost entirely replaced by dyes. These dyes are mixed with a carrier, such as an alcohol and sprayed onto concrete. It's topped with a water-based sealer to create the mottled look, accentuating the unique characteristics of the concrete.

If you have any rough spots or irregularities on your interior concrete floor, use course-grit sandpaper or rent a grinder with a concrete surfacing pad to smooth it out.

Once the surface is even, clean the floor with a mild cleaner such as TSP, and allow to dry thoroughly.

Mask off all walls and trim molding with tape and plastic sheeting. Painter's tape will protect the wall finish without damaging it during removal, but it can peel off the surface if exposed to the dye solution. Place masking tape over the painter's tape to hold the plastic sheeting in place.

Mix the dye with solvent (i.e. denatured alcohol, acetone, lacquer thinner, etc.) according to dye solution instructions. Pour solution into sprayer using a funnel.

Apply the dye by spraying in a circular motion, overlapping as you go. Use a fine-spray tip for light, even coverage (Image 1).

Allow to dry for approximately 20 minutes.

Mop the floor with warm water and a well-wrung mop. Do not allow water from the mop to pool on the floor. Depending on the dye product, mopping may not be necessary. Defer to the product specifications.

Spray on a liquid floor wax, and mop. Use a microfiber cloth to help spread wax more evenly. Another option is to apply a high-gloss, water-based sealer with a paint roller.