CEMP-ET
EI 01S908
1 June 1998
i. Load Test. Load tests will be performed in accordance with ASTM E 1592.
j. Structural Members. Fastener capacities are directly dependent on the strength and
thickness of the supporting structural members. Cold-formed supporting structural members or
subpurlins will have a minimum thickness of 1.5 mm (0.059 in.) and a minimum tensile yield
strength of 345 Mpa (50,000 psi). Hot-rolled structural members will have a minimum thickness
of 6 mm (1/4 in.) and a minimum tensile yield strength of 248 Mpa (36,000 psi).
k. Pull-out Test. For re-roof applications, pull-out tests should be made to check the tensile
strength and anchorage of the fasteners securing the new roof purlins to the existing building's
structural system. Fasteners used in multiples of 2 or more should resist a load consisting of the
tributary area multiplied by a safety factor of 2.25. Single fasteners should use a safety factor of
3.0. Fasteners should meet the minimum size requirements contained in paragraph 7c. For re-
roofing applications, attachment of retrofit framing must be to existing hot-rolled structural
members only. Light-gauge cold-formed steel may be used for retrofit slope conversion. The
design, including all connection details of the cold-formed steel, should be included on the
contract drawings. Attachment to other substrates such as tectum, gypsum board, metal
decking, or other than flange bracing of the retrofit purlins is not permitted.
8. NONSTRUCTURAL METAL ROOF DESIGN REQUIREMENTS.
a. General Design Philosophy. Nonstructural systems are procured using a performance
specification. The design configuration of the system is performed by the designer. The
manufacturer provides a system conforming to the performance requirements and matching the
design configuration and structural requirements. The contractor is responsible for the qualify of
the metal roofing system. The contractor is responsible for providing sufficient information to
ensure design requirements have been met, and may have to provide added substrate support to
adequately resist imposed loads.
b. Seams. Nonstructural systems should have seams located no wider than 400 mm (16 in.)
apart. Seam height and type (crimped, batten, etc.) should be in accordance with manufacturer's
recommendations necessary to enforce the specified weather tightness warranty. End seams in
long runs should be manufacturer-detailed or shown in accordance with SMACNA details on the
drawings.
c. Fasteners and Fastener Spacing. Fasteners should be concealed, corrosion resistant,
compatible with panel materials, and capable of resisting imposed loads. Fasteners should be
manufacturer-furnished or recommended for the intended purpose. The manufacturer's
Underwriter's Laboratory (UL) Class 90 uplift classification number will be submitted for review
and approval. Installation and spacing of fasteners will be in strict accordance with the
classification description.
d. Roof Slopes. Nonstructural metal roofs are not waterproof membranes. They shed water
by sheet runoff and require adequate slope to prevent buildup and seam inundation. Slopes 3 in
12 or greater are required.
e. Thermal Movement. Designers must give consideration to the panel color, building
location, infrared heating and cooling effect of the roof radiating into the night sky. The designer
should use a maximum temperature of 71 degrees C (160 degrees F) for an uninsulated roof to
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