Vertical and horizontal mullions of the modules mate together with the adjoining modules. In the unitized system, the curtain wall is composed of large units that are assembled and glazed in the factory, shipped to the site and erected on the building. In the stick system, the curtain wall frame (mullions) and glass or opaque panels are installed and connected together piece by piece. The following are brief descriptions of commonly used curtain wall framing methods and components.Ĭurtain walls can be classified by their method of fabrication and installation into the following general categories: stick systems and unitized (also known as modular) systems. It is recommended that consultants be hired with an expertise in custom curtain wall design for projects that incorporate these systems. This section incorporates comments about standard and custom systems. Custom walls become cost competitive with standard systems as the wall area increases. Aluminum framed wall systems date back to the 1930's, and developed rapidly after World War II when the supply of aluminum became available for non-military use.Ĭurtain wall systems range from manufacturer's standard catalog systems to specialized custom walls. The wind and gravity loads of the curtain wall are transferred to the building structure, typically at the floor line. The framing is attached to the building structure and does not carry the floor or roof loads of the building. A curtain wall is defined as thin, usually aluminum-framed wall, containing in-fills of glass, metal panels, or thin stone.