A slide-room for installation in a recreational vehicle or other structure is disclosed. The slide-room comprises a shell, which can be constructed from fiberglass. The shell comprises an end wall, a ceiling, a floor, two opposing side walls, and a flange extending from the end wall, wherein the end wall, the ceiling, the floor, the side walls and the flange comprise a one-piece, unitary construction. Also disclosed are methods for molding composite components, such as slide-room. In one specific implementation, the shell for a slide-room is formed from fiberglass using a vacuum assisted resin transfer process.