We start with a 3-pound high density EPS core and shape the base with a 1/4" per foot (2%) slope to the drain. In its raw state, the 3-pound EPS is tough; however, both surfaces (top & bottom) are then coated with a proprietary blend of hard coat epoxies and embedded composite fibers that gives the shower base its ultimate durability and strength. Next, the perimeter flange and curb are fusion welded to the sloped core. It is then coated in our elastomeric waterproofing and crack isolation membrane. It is completely waterproof and ready-to-tile.