PRANCE metalwork is a leading manufacturer of metal ceiling and facade systems.
A curtain wall system is ingeniously designed to accommodate both building movement and the thermal expansion and contraction of its own materials. Buildings naturally move, swaying due to wind loads and settling over time. Additionally, curtain wall components, particularly the long aluminum mullions, expand in the heat of a Riyadh summer and shrink during cooler nights. The system must absorb these movements without compromising its structural integrity or weather seals. This is achieved through carefully engineered joinery. The vertical aluminum mullions are typically not continuous for the full height of the building. Instead, they are "spliced" at each floor or every two floors. This splice joint is designed as an expansion joint; the top of one mullion section fits into a sleeve at the bottom of the section above it, with enough space to allow for vertical movement from thermal expansion. For building sway and inter-story drift (movement between floors during seismic events), the connection points that anchor the curtain wall to the building structure are designed to allow for movement. These anchors often incorporate sliding or rotating connections that hold the wall securely while permitting the building frame to move independently behind it. The gaskets and seals between panels are also made from flexible, durable materials like silicone or EPDM that can maintain a tight seal while being stretched or compressed. This integrated system of flexible anchors, expansion joints, and elastic seals ensures the curtain wall can "breathe" and move with the building, preventing stress buildup, glass breakage, and seal failure.