Tile Underlayment – Where We Are and How We Got Here

Mike Silvers, CPRC, Owner of Silvers Systems Inc. and FRSA Director of Technical Services

Changes in roofing underlayment requirements have evolved in dramatic ways over the last several decades, 
particularly when it comes to tile underlayment. Why have we had so many changes and how has it changed?
For many years, underlayments were primarily viewed as a dry-in, used to provide temporary protection
of the roof sheathing from the elements. For most steep-slope roofs, they were expected to serve this purpose until the roof covering was installed. The code requirements at the time called for underlayments to be  “fastened sufficiently to hold in place” or “fastened only as necessary to hold in place.” The thinking was that once a roof covering was fastened through the underlayment, it wouldn’t need a specific number of fasteners and that their placement wouldn’t be critical. Read more.