Cretex Chimney Seals seal the frame chimney area of both existing and newly constructed manholes. They reduce surcharging/bypassing and lower pumping and treatment costs in a sanitary sewer system. In storm sewer systems, Cretex Chimney Seals provide protection from infiltration of surrounding soil. This infiltration frequently undermines pavements. Cretex Chimney Seals are a product of Cretex Specialty Products (affiliated with Cretex Companies, Inc.). Cretex Specialty Products was established in September 1983 to meet the demand in the municipal and engineering communities for an inexpensive, easy-to-install, durable seal for the frame chimney area of both existing and newly constructed manholes.