- Q. What is the best primer and paint for an unpainted stucco exterior?
A. On new stucco, I recommend a chlorinated rubber paint developed specifically for use on concrete and stucco. Pratt & Lambert Alka-Tite is one such product. On weathered stucco where much of the alkali has washed off, a primer such as Sherwin Williams Masonry Conditioner (diluted with an equal volume of paint thinner), followed with two coats of exterior latex paint seems to work well.