Key to the longest lasting tile roofs is what’s underneath the tile. This underlayment has special reinforcement fibers that allow the tile to be spray foam adhered directly to the underlayment, instead of using the older method of mechanically screwing every tile down. Why spray foam rather then screw? Fewer penetrations through the waterproofing layer means fewer potential leak points over time. On this house we are installing an underlayment called Polyglass PolyStick TU Plus, this is a high-