Building envelope design using metal and glass curtain wall systems

The curtain wall system has evolved rapidly over the past two decades especially with respect to environmental separation. Early systems frequently presented rain penetration problems, were subject to build-up of icicles or condensation and suffered from the failure of glazing seals. Most of these difficulties have been overcome but some difficulty remains at the joints between the curtain wall system and other parts of the building. A definition of curtain wall is provided and the system is described in terms of how it responds to wall design requirements such as airtightness, thermal resistance, vapour resistance, rain protection, and accommodation of structural and thermal movement. Details of junctions at parapets, corners, grade, masonry precast siding, soffits and sloped walls/roofs are presented and discussed.