The invention is a modular wall system and floor system for bathrooms, gang showers or any other room space having at least one generally 90 degree room corner with a first wall panel on one of the two intersecting room walls of said room corner intersecting and joining to a second wall panel on the other intersecting room wall. Each embodiment of the invention features a plurality of spring clips that together with a plurality of globs of adhesive form a room corner attaching means for wall panels or other wall members that intersect one another in a generally 90 degree room corner that provides a tight, closely abutting fit between the adjacent, perpendicularly intersecting panels or members in the room corner.