4.6 METAL BUILDING SYSTEMS
Metal building systems are popular in light commercial construction due to their low first costs and
their fast, simple and efficient assembly. The panels can be engineered in a variety of forms and
finishes and prefabricated in the factory for efficient construction that is relatively unaffected by
weather. The basic wall construction consists of a metal siding mounted on a steel girt system with
an interior finish consisting of a metal liner or gypsum on studs or furring. Metal roofs are similarly
constructed using purlins as the structural elements. The Metal Building Manufacturers Association
(MBMA) has a Low Rise Building Systems Manual that contains design information on metal
building systems, primarily concerning structural issues.
In metal buildings, thermal insulation system integrity is generally associated with the interaction of
the insulation and the structural systems. Since the metal liners and facings are airtight, the
air-tightness of the panel joints control the airtightness of these systems.