reflecting sunlight than darker surfaces. This
keeps roofs 20 to 35 degrees C (35 to 60 degrees F)
cooler, which means less heat will be transferred to
internal building spaces. Demonstration projects
have shown that cooling energy use can be cut by as
much as 40 percent when light-colored surfaces are
used. Coordinate the use of light-colored roofing
material with the user.
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Provide exterior and interior exposed surfaces of metal roof and wall
panels, [roof ventilators,] [louvers], gutters, downspouts, and metal
accessories with a thermal-cured factory finish. Color shall be [selected
from manufacturer's standard colors] [as indicated]. Provide an exterior
finish top coat of [the building manufacturer's standard paint] [50 percent
resin silicone polyester] [70 percent resin fluoropolymer]. Provide
standard dry film thickness of [0.02] [0.025] mm [0.8] [1.0] mil for
exterior coating exclusive of primer. Provide exterior primer thickness
[standard with building manufacturer] [0.005] [0.02] mm [0.2] [0.8] mil.
Interior color finish shall consist of [the same coating and dry film
thickness as the exterior] [a backer coat with dry film thickness of [0.01]
[0.005] mm [0.5] [0.2] mil thick prime coat.] Provide [interior and]
exterior color finish meeting the test requirements specified below. Tests
shall have been performed on the same factory finish and thickness provided.
2.4.3
Testing of Factory Color Finishes
2.4.3.1
Salt Spray Test
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NOTE: The results of the salt spray test will vary
depending on the thickness of the coating.
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A sample of the sheets shall withstand a cyclic corrosion test for a
minimum of 2016 hours in accordance with ASTM D 5894, including the scribe
requirement in the test. Immediately upon removal of the panel from the
test, the coating shall receive a rating of not less than 10, no
blistering, as determined by ASTM D 714; 10, no rusting, as determined by
ASTM D 610 and a rating of 6, over 2.0 to 3.0 mm 1/16 to 1/8 inch failure
at scribe, as determined by ASTM D 1654.
2.4.3.2
Accelerated Weathering Test
ASTM G 23, Method 2, Type D apparatus minimum 2000 hours or Type EH
apparatus minimum 500 hours, no checking, blistering or loss of adhesion;
color change less than 5 NBS units by ASTM D 2244 and chalking less than
No. 8 rating by ASTM D 4214.
2.4.3.3
Flexibility
ASTM D 522, Method A, 1/8 inch diameter, 180 degree bend, no evidence of
fracturing to the naked eye.
2.4.3.4
Adhesion
ASTM D 3359, Method B, for laboratory test and film thickness less than 5
mil and Method A for site tests. There shall be no film removed by tape
applied to 11 parallel cuts spaced 1/8 inch apart plus 11 similar cuts at
SECTION 13120
Page 37
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