Sweep and/or scrape debris and dirt from the floor. Pressure wash the surface if possible to speed up the process.
Clean the basement floor with a solution made of one part bleach, one part water. Liberally scrub the cleaner onto the floor with a stiff brush, but don’t forget to mop up the solution and rinse the floor often.
Allow the floor to dry, using floor fans if possible.
Prepare the Acid Solution
Open windows and doors if possible to increase ventilation and decrease drying time.
Cover your hands with rubber gloves, shoes with rubber boots, eyes with plastic goggles, and nose and mouth with a respirator if you’re in a poorly ventilated area, such as a basement. Muriatic Acid has the distinct smell of rotten eggs.
Mix three quarts of water with one quart of muriatic acid to make a gallon of the etching solution. This will likely cover 100 square feet.
Apply Muriatic Acid
Working with a different scrub brush than you used with the bleach and water solution, scrub the muriatic acid solution into the floor. It’s normal for the solution to bubble, but wait until the bubbling ends before rinsing the floor. Rinse the floor at least twice and allow it to dry.
Vacuum up the white, powdery residue left on the basement floor, and use a wet mop to gather the rest. The residue contains at least part of the basement floor and the remainder of the muriatic acid which acts like sandpaper does to wood, skimming off the top layer to allow for better paint adhesion.
Allow the floor to dry and then apply the paint of your choice to the basement floor. Urethane latex floor paints are believed by many to be a top choice for homeowners because of quick drying time, soap and water clean up, durability, and breathability.