A curtain wall system is an outer covering of a building in which the outer walls are non-structural, but merely keep the weather out and the occupants in. As the curtain wall is non-structural it can be made of a lightweight material, reducing construction costs. When glass is used as the curtain wall, a great advantage is that natural light can penetrate deeper within the building.
The glass and aluminium curtain wall is found in city centres, on many new buildings and it is quite popular as a cladding and exterior wall on all types of commercial, industrial, institutional and residential buildings. The curtain wall is characterized with coloured vision and spandrel glass areas, a grid of aluminium caps and most recently with metal or stone spandrel covers. It is also combined with other types of cladding systems such as precast, brick or stone to create attractive and durable building facades.
The curtain wall comprises a complete cladding and exterior wall system with the exception of the indoor finishes. It is generally assembled from aluminium frames, vision glass and spandrel glass (or metal or stone) panels to enclose a building from grade to the roof. It is available in three system types to include the stick built system, the unitized (or panel) system and the structural glazing system (cap less vertical joints). The glass and aluminium curtain wall is designed to resist wind and earthquake loads, to limit air leakage, control vapour diffusion, prevent rain penetration, prevent surface and cavity condensation and limit excessive heat loss or heat gain. It is further designed to resist noise and fire.
Curtain walls differ from store-front systems in that they are designed to span multiple floors.