2.6
FACTORY COLOR FINISH
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NOTE: Factory color finish will be specified except
when the buildings are to be used for temporary
purposes or where mill finish aluminum panels
provide an acceptable appearance. If factory color
finish is not required, document the rationale for
the decision in the design analysis and remove this
paragraph.
The U.S. metal building industry offers a variety of
color finishes to protect the metal panels against
chemical corrosion and ultraviolet radiation; to
provide long life with minimum maintenance plus
acceptable weathering and color retention; and to
assure chalk, fade, and mar resistance. Some of the
most widely used coatings include, but are not
limited to, the following:
a. Polyvinylidene fluoride (PVF2); a nominal 0.025
mm (1 mil) thick coating modified with a proprietary
resin for toughness; it may be used in most
environments.
b. Silicone-modified polyester (SMP); a thermoset
coating system composed of polyester resin modified
by copolymerization with a functional silicone resin
intermediate designed for added protection against
chemical corrosion and ultraviolet radiation.
c. Plastisol (PVC); a two-coat system consisting of
a polyvinyl-chloride resin dispersed in a
plasticizer top-coat over a corrosion-resistant
primer; it is a high-performance, thick coating
designed for highly aggressive and corrosive
environments with excellent resistance to common
acids, alkalis, and inorganic compounds.
Most coatings may be ordered extra-thick for
buildings in direct contact with salt or chemical
laden air or where a premium finish would be
justified. The thicker coating provides additional
primer and increases the coating's corrosion and
abrasion resistance but it requires a special run by
the coil coater, at least a 22 degrees C (70 degrees
F) environment, and additional delivery time.
Appropriate specification requirements must be added
if the thick film coatings are to be used.
The high cost of preventing corrosion of galvanized
steel panels, together with the fact that cut edges,
scratches and penetrations of the panels expose the
steel substrate, warrants consideration for the use
of solid aluminum which is inherently less
susceptible to damaging corrosion.
Roof panels are available in several standard
SECTION 07416A
Page 18
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