Curtain wall fundamentals

Stick built vs. Unitized curtain walls

Curtain walls are classified by their fabrication and installation. The first category is unitized curtain wall systems, which consist of large units which are assembled and subsequently glazed. Afterwards, the fabricated systems are shipped to the construction site and are attached to the building façade. The vertical and horizontal modules stack together to create a holistic and complete system. In most cases, cranes are used to install them. On the other side, stick systems consist of the curtain wall frame verticals, so called mullions that are connected piece by piece. Usually, these parts are manufactured and then shipped to the site for installation. Typically, vertical mullions run past two floors. Between the mullions, there are splices that allow vertical movement while providing resistance. Sometimes, split vertical mullions ensure thermal movement.

Interior vs. Exterior glazing

Both systems can be glazed either interior or exterior, and they offer both multiple advantages and disadvantages while they are being installed. The advantage of interior glazed systems lies in their appliance for low-rise buildings, or applications with limited interior obstructions. Exterior glazed systems have the advantage that they are installed from the exterior side of the curtain wall.

Water-managed vs. Pressure-equalized systems

Curtain walls can be also classified as either water-managed or pressure-equalized systems. Pressure-equalized systems block all external forces that drive water across a barrier. The inside face of the glass and the inside face of the glazing pocket meet are interconnecting gaskets that serve as air light barriers. The outside face of the glass and outer exposed face of the aluminum functions as a rain screen that directs water away. Water-managed systems on the other hand, incorporate drains and weeps from the glazing pocket instead of zone-glazing.

Protection in cold environments

Back pans are used in colder climates. Those are metal sheets that are crafted from aluminum. In cold climates, insulation should be installed between the back pan and exterior cladding. Back pans provide a second defense against water infiltration.

Standards for architectural design

The driving factors in the design of most buildings nowadays is curtain wall. Therefore, it is important to understand the needs of curtain walls for projects to guarantee optimal performance. Especially glazing firms like GLASSCON GmbH have the appropriate knowledge about the commonly specified codes standards when designing curtain wall systems. Get in touch and receive your free quotation now>>>