Concrete walls must always be prepared before painting, but in some cases previous finishes will also have to be removed so that paint doesn't peel or chip off. Additionally, special sealants, primers and paints may be applied to ensure concrete's endurance in face of the specific elements. Depending on the wall's condition and exposure to the sun, painting professionals will usually estimate between $500 (~250 sq. ft.) and $2,000 (~1,000 sq. ft.), depending on wall area to cover.
O'Neil patches shallow holes and divots with Ready Patch because it dries fast, sands smooth, and stays flexible. Deep cracks and rotten spots are best repaired with two-step epoxies, such as those made by Advanced Repair Technology. (For a step-by-step instructions, see Repairing Rot with Epoxy.) The days of using polyester auto-body fillers on wood are over. "They cure too hard," says Portland, Oregon–based painting contractor Kathleen George. "They look good at first, but then they peel away."
Painting Contractors Co