Abstract: A structural, shower base assembly is provided. The assembly includes a tile-over shower base pan, a tile drain grate frame, a double threaded flange nipple, and a rubber gasket. The tile-over shower base pan includes a dorsal side pre-sloped to allow for consistent water draining to a dorsal opening of a centered drain hole of the tile-over shower base pan, and a ventral side having a ventral opening of the centered drain hole of the tile-over shower base pan and a reinforcement ring. The tile drain grate frame is compatible with the dorsal opening and the ventral opening. The double threaded flange nipple is compatible with the tile drain grate frame and an industry standard plumbing drain body. The rubber gasket is compressed to the reinforcement ring to seal a connection between the double threaded flange nipple and the industry standard plumbing drain body.