Steel Curtain Walls That Get the Curtain Call by Chuck Knickerbocker Photo courtesy TGP MODERN CURTAIN WALL SYSTEMS REQUIRE STRUCTURAL SUPPORTS AS STRONG AS THEY ARE VERSATILE TO KEEP PACE WITH TODAY’S INCREASINGLY LARGE FREE SPANS, CHALLENGING ANGLES, AND SOPHISTICATED GLASS- CLAD AESTHETICS. WHILE STEEL CURTAIN WALL FRAMES HAVE LONG MET STRENGTH CRITERIA, THEY HAVE ONLY RECENTLY PROVIDED THE NECESSARY DESIGN FLEXIBILITY. Steel’s reputation as the workhorse of the modern building industry is well-earned. From soaring bridges to skyscrapers, it is able to withstand some of the most demanding structural loads without deforming, splitting, or cracking. Despite its exceptional performance, manufacturing limitations have prevented its widespread use as the primary framing material in glazed curtain wall assemblies. However, in recent years, advanced processing methods have overcome this challenge. Using cold-roll forming techniques developed in Europe, manufacturers feed continuous steel coils through dies, forming basic, closed profiles that can frame the curtain wall. Another option is to laser- cut long (i.e. up to 14.9 m [49 ft]) steel plates (3.8 to 38 mm [0.15 to 1.5 in.]), which are then laser-welded together into a range of different shapes, from C, T, I, H, and L profiles, to custom shapes. While the 56 the construction specifier | march 2016 CS_March2016.indd 56 2016-02-12 3:21 PM