UNITIZED CURTAIN WALL SYSTEM
In unitised construction, on the other hand, the curtain wall is composed of large units that are assembled in the factory, shipped to the site and erected on the building. Aluminium profiles are used to form the frame, which is normally one-storey high. Opening vents, glazing and infill panels are built into units before being transported to site. As with stick construction, each unit is usually supported by the floor or perimeter beams. For unitised curtain walling, about 30% of the work is done on site, while 70% is carried out in the factory. The complete assembly of the units in the factory brings a number of benefits.
- Can be installed from the interior of the building. This is ideal for high towers or building sites where there is a tight footprint
- Units can be assembled while the structural frame is being built. The facade can also be
- Quicker installation, requiring less manpower on site
- Completed a floor at a time, allowing parallel internal work
- Concurrent manufacture and site preparation
- Less space is needed on site for layout - another
- No need for scaffolding
- Improved quality control
Another advantage of unitised systems is that, unlike stick systems, they do not transfer impact noises from floor to floor or horizontally from room to room. This is because the unitised panels are separated by linking gaskets. The different materials (ie, gasket to aluminium), become acoustically excited to different levels, thus creating full separation at the junctions between units.
The increased use of factory assembly introduces other important considerations.