ProSpec has developed Stayflex, a new thin set designed to bond large ceramic tile, marble and natural stone to walls without slippage or sag. The thin set is formulated with polymers that increase bond strength to keep the tile or stone in place, even those weighing up to 11 lbs., the company says. Designed for commercial and residential uses in both interior and exterior applications, Stayflex meets ANSI A.118.4 and A.118.11 standards and works over drywall, cement backerboard or any other cement substrate.For details, circle 163 on the Reader Inquiry Card.