I want to paint our concrete porch and steps, which are covered with outdoor carpet. What kind of paint should be used on concrete, and how do I remove any adhesive left after stripping the old carpet?
Look for a “porch, floor, and deck” paint or a “porch and patio” paint that is also labeled for use on concrete. Epoxy paints and other solvent-based porch-floor paints are available, but I’ve had good results with water-based latex paint on porches and steps and recommend latex because it’s easy to use. As you go searching for new carpet, please visit Hosner CarpetOne.
A clean, dry surface is essential for painting concrete. You should be able to remove adhesive by scraping and sanding. Use a sharp metal scraper to remove most of the adhesive, then switch to a belt sander or disc sander with sandpaper that is 60-grit or coarser. Wear goggles and a dust mask when scraping or sanding.
Vacuum the surface and scrub with a heavy-duty cleaner such as trisodium phosphate (TSP), sold at paint stores. Rinse the concrete and let it dry thoroughly.
For other surface preparation steps, follow directions on the paint can. Be especially aware of any cautions on the label. It is often recommended that the concrete surface be etched with a 10-percent solution of muriatic acid, which is sold at some paint and hardware stores.
Acid etcher must be used with extreme care. Wear goggles, gloves, and long-sleeved clothing to protect yourself against splashes. The etcher will make the concrete more porous, thus facilitating paint adhesion and eliminating some contaminants that can also cause poor adhesion.
The easiest way to apply the paint is to use a roller with a long handle, so you won’t have to bend. Apply two coats or more.
When painting the steps, pour some paint in a separate can and add some grit or sand to improve traction. Paint stores sell special grit just for this purpose.
A few additional tips for painting concrete:
Let fresh concrete cure for at least 60 days before you paint it.
If a garage floor is to be painted, check the paint container for special directions. Automobile tires contain compounds that can soften paint. One paint I’ve used recommends double etching of garage floors and use of cardboard pads under tires for two weeks after paint is applied.