The rise of retrofit metalDavid W. Boozer, Allen Lancaster
During the early 1970s, a handful of roofing contractors
realized the potential of retrofit metal roof systems and pioneered
the development of a new roofing market segment. These innovators
used materials common to their businesses to adapt early metal roof
systems to conventional low-slope roof systems. Many mistakes were
made, but their successes built the basis for current retrofit
metal roof systems.
Initially, framing systems used for retrofit metal roof systems
were crude and simple. The basis for adding slope to a relatively
flat roof was wood. Wood studs, rafters and sleepers were used and
anchored to existing roof systems as necessary to provide slope and
support. Wood stud framing gave way to wood trusses, steel-angled
truss framing, steel stud framing and specialty steel framing
established specifically for retrofit metal roofing
applications.
In addition, manufacturers of pre-engineered metal buildings
that had relationships with these pioneer roofing contractors began
developing specific framing shapes and design data. Equipment was
developed to produce cold-formed steel shapes for hat sections,
posts and purlins, all of which still are the basis for current
products that support retrofit metal roof systems.
As with most new products, methods for achieving desired goals
and results vary among manufacturers and systems. For every
solution to a problem, there is another solution that is equally
correct. This is true in metal roofing and retrofit framing. Most
metal roofing manufacturers have products, which may vary, that
provide support and slope for their roof systems. Following is some
general information about retrofit metal roof systems, as well as
specific information...
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