Curtain wall systems are non-structural cladding systems for the external walls of buildings. They are generally associated with large, multi-storey buildings. Curtain walls separate the interior from the exterior, but only support their own weight and the loads imposed on them (such as wind loads, seismic loads, and so on) which they transfer back to the primary structure of the building. This is in contrast to many forms of traditional construction in which the external walls are a fundamental part of the primary structure of the building.

Curtain walls can adopt Spider system, Stick system, Semi-unitised or Unitised:

+ Spider system does not use aluminum frame, but uses spider fitting, glass catch, connector and bolt combined with the transparency of the glass to create a clear space without restricted visibility like the Unitised, Semi-Unitised or Stick system.

Stick system are installed piece by piece on site, with the glazing inserted into the frame from the inside or the outside depending on access conditions. Unitised systems are pre-fabricated in modules off-site and delivered in panels.

Unitised system is better able to exploit the benefits of factory condition manufacturing and quality control and require lower installation time on site.

Semi-Unitised system have vertical mullions and horizontal transoms installed on brackets which are anchored to the columns/slabs. Cut to size glass is structurally glazed to the aluminum sub frame by structural sealant. The sub frame with the glass is installed on the grid work. Semi-Unitised system requires more installation time onsite than Unitised system but less installation time onsite than Stick system.

Representative projects that Viet Hong has installed Curtain wall Semi-Unitised system include: TLE Building 44 Hao Nam, TLE Building 75 Trần Thái Tông.