Painting outdoor concrete areas, such as pool decks and patios, has been made easier thanks to the newest concrete paints. They are made to breathe with the cement, which prevents much of the blistering and peeling of the past. The main concerns when painting are the age and cleanliness of the concrete. You must give a new concrete slab at least a month to cure before painting; if it's an older slab, it will need to be thoroughly cleaned first. Give yourself a weekend for the project, especially if the concrete needs to be cleaned.
Clean the concrete. Wet it down and put an alkaline degreaser in a tub. Dip a long-handled broom into the tub and scrub onto the concrete. Let it sit for 15 minutes and power-wash the slab. If you have a stain that still has not come off, scrub the area again and let it sit. Rinse after another 15 minutes. Allow the concrete to dry completely.
Apply a concrete sealer. Read the manufacturer's directions on the paint can. Sometimes, a special brand of sealer is recommended, as well as specific ways to prepare and paint to keep the warranty in effect. Use at least two coats of sealer and allow it to dry to the touch.
Paint. Make sure you use a breathable cement paint; no other paint will work well on concrete. Pour the paint in a paint tray and use a paint roller on a long handle. You can paint faster using a paint sprayer, but make sure you cover all walls or anything around the area you are painting to protect it from overspray. You will need at least two coats. If you are content with the colour and consistency after two coats, you can stop; if not, one more coat should do it.