How to Paint a Concrete Floor

A fresh coat of paint makes everything look better, so even your old concrete gray basement floor or your stained garage floor can be made to look--not just better--but really good. Painting concrete isn't hard, but because concrete is porous you do have to do more up front work before starting to paint. This can be time consuming just because of the number of steps involved, but if you think your basement or garage would look better with some upgraded (or new) paint--here's how to paint a concrete floor.

Things You'll Need

• Plastic sheet
• Tape (duct or masking)
• Vacuum cleaner
• TSP (Tri Sodium Phosphate) available at home stores
• Buckets or warm water
• Sponge mop
• Etching compound or Muriatic acid (for alkyd paint) or Phosphoric acid (for latex paint)
• Concrete sealer (perhaps)
• Concrete patch (perhaps)
• Concrete primer (perhaps)
• Concrete paint
• Roller, brushes, paint trays, cloths

Instructions

1. Perform a moisture test on your concrete floor. Tape a 2-square-foot piece of plastic to the floor and wait for a couple of days. If any signs of moisture appear under the plastic, you have some moisture penetration that needs to be sealed before the floor can be painted.

2. Patch any holes or rough spots in your concrete floor using concrete patch (available at home stores), and be sure to read and follow the directions on the package.

3. If your floor has been previously painted, use a paint scraper to remove any loose paint and vacuum up all the pieces and any dust or dirt on the surface.

4. Get rid of any oil or grease that might be on the surface by thoroughly cleaning the floor with TSP and warm water. After washing the floor, rinse it with clear, warm water.

5. Depending on the paint your have chosen, now is the time to "etch" the concrete floor. Apply the etching compound recommended by the paint manufacturer or the acid and water (10 parts water to one part acid) to the floor in sections and allow it to dry thoroughly, then vacuum the floor to remove any dust from the etching.

6. If your concrete needs to be sealed, now is the time to do it. You can buy concrete sealer at a home store and it just rolls on like paint. Allow time for it to dry (read the directions) before moving on.

7. Finally, it may be time to paint. Some paint manufacturers combine paint and primer in one can so you don't need to apply a separate primer to the floor before painting. Check when you buy your paint.

8. Apply the paint in small sections. Start at the far end of the room and work your way towards the stairs or door. It's best to apply the concrete paint in two or three thin layers rather than trying to get the job over with and applying one thick one.

9. Once the paint has dried, you can do one final layer of sealer to protect the paint and ensure it lasts for years to come.

Tips & Warnings

• Some concrete paints dry very slippery. You can get paints with silicate granules to provide traction right in the formula or you can spread silicate particles when you apply the paint.

• New concrete floors need to cure for a minimum of 30 days (some experts suggest at least a year) before you paint them.

• Acids for etching and sealers can be noxious and dangerous if they get into your skin. Always wear safety goggles and gloves when working with them.

• Make sure you have adequate ventilation when preparing or painting your concrete floors.