The surface must be clean and free of all dirt, chalk, mildew, loose or peeling paint. New masonry panels must be clean and free from bondbreakers, form release agents and other surface contaminants. (This may require brush blasting with sand.) The pH of the surface must be below 10 and all efflorescence must be removed prior to painting.
Note: When applying any product to brick, always test a small area first to brick for adhesion and discoloration. Glazed brick must be etched prior to painting. Some porous bricks may require two coats of #235 100 Acrylic Primer. Some bricks contain iron salts, which may rust and bleed through latex coatings. If there is a bleeding problem, use #160 Oil Base Primer.
Always prime new or bare masonry with the appropriate primer.