Alliance Gator Block Bond XP 200117147 10 oz Low VOC Polyurethane Glue for Pavers is one of the strongest polyurethane adhesives on the market. It is specially formulated for overlays, pool copings, steps and wall caps, concrete pavers, wet cast, natural stones, retaining walls, masonry units and bricks.This polyurethane adhesive is formulated to provide a permanent bond in 24 hours to the above materials if properly installed.