Injected as a single component, catalyzed AV-280 Hydrofoam is a moisture activated, high viscosity, MDI-based polyurethane resin. The chemical reaction is catalyzed by using AV-281 Hydrocel and uses moisture as an initiator. AV-280 was designed to not easily wash away where high volume water flow is present. It is injected into the substrate and reacts with moisture to fill voids, stop active or potential water leaks, and stabilize coarse materials. AV-280 withstands wet/dry cycles and cures to form a dense, impermeable semi-rigid foam.