What's happened is that the bricks and mortar joints have absorbed the acid and the impurities it carries. Once in, even a thorough water rinse can't get it out. As the acid attacks the bricks and mortar, it mobilizes mineral salts within the masonry, creating the stains. PROSOCO carries several products which can help correct this fairly common mistake, including Sure Klean® 800 Stain Remover
and Sure Klean® Ferrous Stain Remover
. Which one is right for you depends on the type of brick and mortar you're cleaning.