"However, for rough surfaces such as brick, the adhesion promoter should further comprise organofunctional silanes, particularly organosilane esters such as amino alkyl silicones, such as Silquest A-1106 sold by OSi Specialties Inc., which is an aqueous solution comprising less than 50% 3-aminopropyl-silanetriol, more than 50% water and less than 2% ethanol." . . . . .