Unitized Glass Curtain Walls System Waterproof Exterior Aluminium Frame Structural Design

Stick and Unitised Curtain Walls:

curtain walling is a building envelope that is intended to support only its own weight and withstand the effects of environmental forces such as wind. It is not intended to assist the structural integrity of the building. There are two main types of curtain walling construction: “stick” and “unitised”.

In stick construction, the curtain wall frame is constructed mainly on site with mullions and transoms supporting glass, spandrel panels, metal panels and brise-soleils, connected piece by piece. Each mullion is usually supported by the floor or perimeter beams.

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.

STICK CURTAIN WALLING
Stick curtain walling systems are versatile and allow for the integration of other systems, such as sliding doors and windows. They tend to be less specialised and can be built by all types of fabricators as they are not dependent on having a large factory.

However, stick systems do require multiple steps to erect and seal the wall, which means more time is spent on site – an approximate rule of thumb would be that 70% of the work is carried out on site, with 30% in the factory. This incurs further costs, such as labourers’ time.

UNITISED CURTAIN WALLING
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.

These include:

Improved quality control
Concurrent manufacture and site preparation - units can be assembled while the structural frame is being built. The facade can also be
completed a floor at a time, allowing parallel internal work
Quicker installation, requiring less manpower on site
No need for scaffolding
Can be installed from the interior of the building. This is ideal for high towers or building sites where there is a tight footprint
Less space is needed on site for layout – another advantage