ACTFLEX PU500 forms a uniform elastic gel at high water contact and expands 6–12 times into a resilient open-cell foam at lower contact, so it seals active leaks in minutes across varying moisture levels. The cured material stays highly elastic in dynamic joints and vibrating structures, bonds to concrete and masonry at greater than 1.18 MPa, and resists contaminants found in water-infiltrated environments. Inject it neat with single-component equipment into tunnels, basements, diaphragm walls, segmental linings, reservoirs, wastewater structures and precast joints. Best suited to permanently damp or regularly wetted conditions; not a structural repair, not UV stable and not certified for potable water.