Alkali Resistance: Color loss and overall
deterioration of paint film on fresh masonry.
Oil-based paint or vinyl acrylic latex paint was applied
to new masonry that has not cured for a full year. Fresh
masonry is likely to contain lime, which is very alkaline.
Until the lime has a chance to react with carbon dioxide
from the air, the alkalinity of the masonry remains so
high that it can attack the integrity of the paint film.
Allow masonry surfaces to cure for at least 30 days, and
ideally for a full year, before painting. If this is not
possible, the painter should apply a quality,
alkali-resistant sealer or latex primer, followed by a top
quality 100 percent acrylic latex exterior paint. The
acrylic binder in these paints resists alkali attack.