Painting Concrete Walls and Floors Gray just isn't your color. Well, here is a way to spruce up a dull concrete wall or floor by painting it. Be creative. Instead of sticking to one color, choose a theme and paint it. Try painting bowling lanes on the floor. All you need to add are the bowling pins and a bowling ball. Bowling not your game? Try your hand at shuffleboard. Can't play golf because it's raining. You'll be the envy of the neighborhood with your own indoor golf course.

Everyone has a favorite sports teams. Paint the team logo on the floor, the walls, anywhere you like. Or try painting the whole baseball, basketball, or even football field on the floor.

Step 1: Clean the Area: All interior masonry walls must be clean and free of loose paint, cement particles or any other foreign matter before painting. Any sources of moisture must be eliminated before painting.

Step 2: Acid Etching: New interior walls should be acid etched before painting (see instructions below.) Existing coatings can be repainted where the coating is sound. Any bare spots (including areas revealed when scraping loose and peeling paint) should be acid etched before painting.

Carefully prepare a solution of one part full-strength muriatic acid with three parts water. Always Add the Acid to the Water to Prevent the Splash of Hot Acid. Never Pour Water Into Acid.

Use one US gallon of this solution (3.78 liters) per 100 square feet (9.3 square meters) of floor, and scrub with a stiff fiber bristle brush while applying. Allow the solution to remain on the floor until it stops bubbling. Flush the solution off thoroughly with clean water. If the surface is not dry within a few hours, flush it with water again. The surface must dry evenly. If puddles develop, the solution will become more concentrated. This will affect the performance of the coating applied over it.

After the surface has dried, use a vacuum to remove the powder that is created by etching. Failure to remove this powder will result in poor adhesion. Painting can begin when the surface is chemically neutral and dry. When a proper etch has been attained, the concrete will have a surface texture like #1 or #2 sandpaper.

• Caution:  Muriatic acid is an aqueous solution of approximately 35% hydrochloric acid. It is capable of producing severe chemical burns as a result of contact with skin or eyes. Muriatic acid is also capable of producing marked irritation of the nose and throat resulting from the inhalation of vapors. In some cases, contact with the eye will cause blindness. All persons handling this material should be aware of this danger and avoid these hazards. Any eye contact with muriatic acid solution should be followed immediately by irrigating the eyes with plenty of water. Areas of the body contaminated with etching materials should be washed immediately with plenty of water. Burns should be treated according to medical advice. Always wear rubber boots, rubber gloves, and work goggles when using Muriatic acid. Always follow all label instructions.

Step 3: Apply Masonry Paint: Deteriorating concrete can produce loose sand and pebbles on the surface of a concrete wall. The most common cause for this is poor quality concrete or improper curing. Deteriorating concrete must be repaired or replaced before painting. A white incrustation called efflorescence is often found on the surface of interior masonry walls. This occurs when salts and free alkalis are leached from inside concrete or cinder block walls and transported to the surface as water moves through the masonry material. In conjunction with acid etching, the application of a properly formulated acrylic latex interior masonry paint is the best way to prevent this problem. Acrylic latex block fillers and waterproofing paint are recommended for this application.

Step 4: Curing the Area and Choosing Paint: New concrete floors must be allowed to cure for 90 to 180 days before painting (see instructions for acid etching.) All bare concrete floors must be acid etched before painting. This is especially important where the demands of construction require the "quick-painting" of floors in less than 90 days. Previously painted concrete floors do not need to be acid etched where paint is sound. Acid etching should be done where bare spots occur or are revealed by scraping loose or peeling paint. Unless you know that your basement floor has a plastic moisture barrier, a latex floor coating must be used. Latex floor coatings allow moisture to pass through dry film. Oil base coatings will not. If a plastic moisture barrier is present, either an oil or latex floor coating may be used. If an oil base coating is used in a basement, the basement must be well ventilated to allow solvent vapors to leave the building.