Most exterior paint around here fails because of prep, not the color. Pollen, chalking and last year’s coating have to come off first. Wash. Scrape. Prime. Then paint. South and west walls take the worst of the sun — those get the attention, not a fresh coat over last year’s chalk. Siding, trim, doors, soffits and the spots that peel first. If a wall is not ready for paint, we say so before the color goes on. We wash when the house is going to be painted, so the new coat can hold. A wash with no paint plan is a different job.