A concrete patio is a plain thing when first poured, and a sad thing when dressed in stained and peeling paint. Fortunately, it is not hard to repaint a concrete patio. Whether you want a solid block of color or are ready to try a more ambitious project, you can have your patio dressed in its best in no time.
Empty everything from the patio and sweep away any leaves, dust or other debris with the broom.
Mop the patio with TSP or another de-greaser. Use the scrub brush on any tough stains. Soak up oil spots with kitty litter, and then use the scrub brush and TSP to clean up any residue.
Remove old paint from a smaller patio (10' x 10' or so) by mixing 1 cup of dishwasher soap and 2 quarts of hot water. Pour the solution on a small section of painted concrete and allow it to stand for 10 to 15 minutes. Break up the paint with the wire brush and scrape it away with the scraper. Repeat by sections until all of the old paint is gone.
Remove old paint from a larger patio by using a concrete paint stripper, available at your local home improvement store.
Patch any cracks or holes in the concrete with cement filler. Allow it to set overnight.
Test to make sure your concrete is sufficiently well sealed to take paint by taping a 1' by 1' square of plastic wrap onto the concrete and leaving it overnight. If there is condensation beneath it in the morning, your concrete needs to be sealed before you can paint it. Contact the manufacturer to make sure your sealer is compatible with your primer and paint.
Use the roller to coat the concrete with primer. Use the brush to get into any little corners, or to edge the part near the house. Let it dry overnight.
Use a clean roller to apply a coat of paint over the primer. Cement color dries darker than it goes on, so don't fret if the initial coat looks light.
Add another coat of paint if you think the patio needs it.
Apply the sealer and make sure no one walks across the patio for at least 24 hours.