Standard Facade systems are non-structural cladding systems for the exterior walls of buildings. They are often associated with large multi-storey buildings.
Curtain walls separate the interior from the outside, but only support their own weight and the loads they return to the building and transfter to the main structure of the building (wind loads, seismic loads, etc.). This is in contrast to many traditional building forms in which the exterior walls are an essential part of the building’s main structure.
Typically curtain wall systems include a lightweight aluminum frame onto which glazed or opaque infill panels can be fixed. These infill panels are often described as ‘glass’, whether or not they are made of glass.
Unassembled systems are pre-fabricated off-site as modules and delivered in panels. Uncombined systems take better advantage of production and quality control under factory conditions and require shorter installation time in the field.
There is a wide variety of infill panels for curtain wall systems, including:
Vision glass (can be double or triple glazed, contain low-e coatings, reflective coatings, etc.).
Spandrel (blind) glass.
Aluminum or other metals.
Stone or brick lining.
Terracotta.
Fiber reinforced plastic (FRP).
Louvers or vents.
Panels are usually composites with coating materials bonded or “sandwiched” to an insulated core, such as polyethylene (PE) or polyurethane (PUR), a profiled metal core, or a mineral core.
Frame and panel designs are very complex as they have to perform multiple functions:
Transferring loads back to the main structure of the building.
Providing thermal insulation and preventing cold bridging and condensation.
Providing fire, smoke and acoustic separation. This is particularly difficult at the joints between the curtain wall system and interior walls and floors.
Preventing water ingress.
It accommodates differential motion and deviation.
Preventing panels from falling off the frame.
Allowing to open windows.
Prevention of dirt accumulation.
In high-rise buildings, access systems should be provided to allow regular inspection, maintenance, cleaning and replacement (especially the replacement of outer seals).