| abstract |
A concrete and masonry waterproofing composition comprises a major amount of a polyurethane and a minor amount of a penetrant. The polyurethane is desirably made from a polyether polyol or a polyester polyol intermediate, wherein the polyol is a diol or a triol. Such intermediates are reacted with a polyisocyanate. Cure, that is, chain extension occurs upon contact with moisture in the air. The penetrant is an organosilane having the formula: <IMAGE> (FORMULA I) where R1 is an aliphatic having from 1 to 18 carbon atoms and wherein R2, R3, and R4, independently, is an alkyl having from 1 to 6 carbon atoms, or an organosiloxane having the formula: <IMAGE> (FORMULA II) wherein R7 is an aliphatic having from 1 to 18 carbon atoms and R5 and R6, independently, is an alkyl having from 1 to 6 carbon atoms, and wherein n is 2 to 20. Improved results are obtained when the composition is applied to masonry or concrete in that water absorption is much lower than that obtained with either solely a polyurethane coating or solely a penetrant, and application ease is improved in that a single coating is used to both penetrate and seal. |