Type CB
Available as one or two
Will withstand
(Urethane
component. Generally low
moderate ponding
aromatic)
permeability but some are
water. Use as base,
considered permeable. Good
intermediate and
abrasion resistance,
finish coat system,
tensile strength,
or as base and
elongation, impact
intermediate with
resistance, and low
Type CF finish coat.
temperature flexibility.
Standard dry time of
High solids content.
4-6 hours with cure
Darkens and chalks on
time of 10-24 hours.
exposure.
Fast dry time of 1-20
minutes with cure
time of 10-24 hours.
Type CF
Available as one or two
Will withstand
(Urethane
component. Generally low
moderate ponding
aliphatic)
permeability but some are
water. Use only as
considered permeable.
finish coat over type
Excellent abrasion
CB base and
resistance, tensile
intermediate coats.
strength, elasticity
Recommended where
impact resistance, and low
highly weather
temperature flexibility
resistant or
Moderate solids content
aesthetic finish coat
Good color and gloss
required.
retention.
Protective coating shall be as approved by the foam manufacturer for use as
the coating component of a sprayed polyurethane foam roof system. Coating
shall consist of separately applied base, intermediate and finish coat of[
one-component silicone (Type A),][ two-component silicone (Type B),][
two-component urethane-aromatic (Type CB),][ or][ combination system of
two-component urethane-aromatic with two-component urethane-aliphatic
finish coat (Type CB and Type CF)]. Coating shall bond to urethane foam
and shall have the following minimum properties:
[2.2.1
Type A Coating
Silicone rubber, single component. Uncured silicone rubber shall have the
following values when tested for specified properties in accordance with
specified test methods:
Properties in Metric Units
Properties
ASTM Test
Value
Units
Solids Content
ASTM D 2697
60, minimum
% by volume
Solids Content
ASTM D 2697
70, minimum
% by weight
Flash Point
ASTM D 56 or
38, minimum
degrees C
ASTM D 93
Properties in Inch-Pound Units
Properties
ASTM Test
Value
Units
SECTION 07570
Page 20
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