Quellmax bentonite waterstop tapes are designed to stop water ingress through non-movement joints in reinforced concrete structures. They are suitable for both horizontal and vertical applications and provide reliable, fast expansion upon contact with water. Quellmax Blackstop, our standard bentonite tape, has repeatable swelling capacity up to 500% from it's formula of high-sodium bentonite embedded in a matrix of macromolecular natural rubber with special fillers and crystalline admixtures. With the same formula, Quellmax Plus performs at the same capacity, but is coated with a unique, patented rain-protection coating that prevents premature swelling of the table for up to 72 hours. During concrete construction, the alkalinity of the fresh concrete dissolves the coating, activating the Quellmax Plus waterstop.