PlyA layer of felt or ply sheet in a built-up membrane roof or waterproofing system.Related Articles:The 4 Best Options for Repairing or Upgrading EPDM Roofs - Part I4 Best Options for EPDM Roofs – Part IIBest Commercial Roofing AtlantaWhat is a Built-Up Roof System?Coating vs Replacement : Commercial Roofing« Back to Glossary
