Designing Metal Ceilings for Exterior Soffits by Edward Williams Images courtesy Chicago Metallic Corporation EXTERIOR SOFFITS PERFORM ESSENTIAL FUNCTIONS FOR VENTILATING, SHADING, AND DIRECTING WATER AWAY FROM A BUILDING. REGARDLESS OF GEOGRAPHY OR CLIMATE, EXTERIOR SOFFITS ARE SUBJECTED TO POSITIVE AND NEGATIVE WIND LOADS. TO PROTECT OCCUPANTS AND THEIR SURROUNDINGS FROM DAMAGE, BUILDING CODES HAVE REVISED PROVISIONS FOR WIND SPEEDS AND RISK CATEGORIES. Metal ceiling systems can meet the performance challenges of exterior soffits, as well as support buildings’ aesthetic and sustainability goals. Constructed mostly of aluminum, these assemblies are durable and do not deteriorate or deform. Conventional materials in exterior soffits include: • gypsum board and plaster; • wood and plywood; • vinyl; and • exterior insulation and finish systems (EIFS). 72 the construction specifier | january 2013 CS_Jan2013.indd 72 12/12/12 9:35:45 AM