National Gypsum Permabase or USG Durock
- Rigid substrate made of Portland cement, aggregate and fiberglass mesh.
- Suited as underlayment for tub and shower surrounds, countertops, flooring and other interior and exterior applications.
- Highly moisture resistant. Will not rot, disintegrate or swell when exposed to water.
- 30-year limited warranty on interior applications. 10-year limited warranty on exterior applications.
- Cut with utility knife and straight edge.
- 90% Portland cement and ground sand. Contains no asbestos, glass mesh, formaldehyde, or gypsum.
- Lightest cement board available. Cuts easily.
- Features exclusive EZ Grid recessed fastener pattern to make installation easier.
- Provides superior protection agains moisture damage and mold growth.
- Limited lifetime product warranty.