WHY UNITIZED
Unitized curtain walls have emerged as the favored method for enclosing buildings, embraced by building owners, architects, and contractors for their numerous advantages. These systems enable swift enclosure of buildings, expediting construction timelines for earlier occupancy. Unlike stick-built curtain walls, unitized systems offer a more uniform fabrication process, resembling an assembly line, conducted indoors under controlled conditions.
Nevertheless, like any construction product, the more unitized systems are utilized, the better we understand their limitations. This article delves into three common issues encountered with unitized curtain walls, offering insights on how to address them. Given that unitized curtain walls represent the cutting edge of curtain wall technology, it is crucial for designers, consultants, and contractors to grasp their technical constraints. This understanding is vital for developing effective designs that account for the full scope of the building enclosure.
There are two types of alignment conditions that must be considered with unitized curtain wall construction:
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Alignment between unitized panels
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Alignment between unitized panels and projecting slabs, canopies and other offsetting structural features of a building.
Curtain wall manufacturers have reliably dealt with the issue of panel-to-panel alignment by developing structural alignment clips that can be slid across the interlocking heads of adjoining panels to maintain horizontal alignment (Figure 1), and by refining the designs of their lifting lugs that help to hold the vertical alignment between panels at their stack conditions (Figure 2). The alignment challenges that manufacturers now face are the unique project-specific building features that interfere with typical panel alignments and must be dealt with on a project-by-project basis.
ALIGNMENT
