NOTE: Where local conditions require highly
moisture resistant construction, specify Fiber
Reinforced Cement Sheathing Board only and delete
Glass Mat Gypsum Sheathing Board for applications of
PB systems, Local experience is the best guide on
where highly moisture resistant construction is
required, but specify Fiber Reinforced Cement
Sheathing Board for buildings near seashores and in
all areas identified in the ASHRAE Handbook of
Fundamentals as "humid." Include both Fiber
Reinforced Cement Sheathing Board and Glass Mat
Gypsum Sheathing Board for applications where local
conditions do not require highly moisture resistant
construction.
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2.2.1
Fiber Reinforced Cement Sheathing Board
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NOTE: Cement sheathing boards meeting ASTM C 1186
are manufactured in four grades ranging in minimum
wet condition flexural strengths from 4 MPa (580 psi)
for Grade I to 18 MPa (2610 psi) for Grade IV.
Select Grade I unless wind load calculations require
greater flexural strength. Justify different types
by wind load calculations.
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a.
Meet ASTM C 1186, Type B, Grade [I] [_____].
b.
Non-combustible per ASTM E 136.
c.
Nail Pull Resistance: No less than 534 N (120 lbf) when tested in
accordance with ASTM C 473.
d.
Thickness no less than 13 mm (1/2 in).
e.
Water Absorption not to exceed 17 percent.
[2.2.2
Glass Mat Gypsum Sheathing Board
a.
Conform to ASTM C 1177/C 1177M.
b.
Nail Pull Resistance: No less than 534 N (120 lb) when tested in
accordance with ASTM C 473.
]2.3
ADHESIVE
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NOTE: Delete the adhesive when using Class PM EIFS.
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[Manufacturer's standard product, including primer as required, and shall
be compatible with substrate and insulation board to which the system is
applied.
]2.4
LATHING AND FURRING
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SECTION 07240
Page 19
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