Dow Protected Membrane Roof EN - Manual (Page 7)

®™Trademark of The Dow Chemical Company (“Dow”) or an affiliated company of Dow
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7
Components
S T Y R O F O A M ™ B R A N D E X T R U D E D P O L Y S T Y R E N E F O A M I N S U L A T I O N
Function
Provide thermal properties:
STYROFOAM ™ Brand Extruded
Polystyrene Foam Insulation has
a high aged thermal resistance
(R-value or RSI) when compared
with competitive roof insulations.
Provide membrane protection:
By installing the insulation over
the membrane, the membrane
is kept at a relatively constant
temperature year-round and
protected from weathering,
mechanical damage and abuse.
Specification
The insulation shall
meet CAN/ULC S701 Type 4.
Install required thickness of
STYROFOAM ™ Brand Extruded
Polystyrene Foam Insulation
unbonded over the roof mem-
brane. Install a slip or separation
sheet over the membrane if the
membrane is coal tar or Type 1
or 2 asphalt, or if required by
the membrane manufacturer.
Butt boards tightly together
with a maximum 3/8" (9 mm)
gap between boards, staggering
end joints. The recommended
stagger between each board is 4'.
However, in cases where boards
have been cut to fit, maximize
the stagger where possible. At a
minimum, each board should
have at least an 8" (200 mm)
stagger.
Bevel edges to fit closely to
cant slopes.
Fit around protrusions and
obstructions with a maximum
3/4" (19 mm) gap to minimize
heat loss.
Multi-layer foam installation:
• The bottom layer of insulation
(the layer directly on the
membrane) must be at least
2" (50 mm) thick.
• The bottom layer must be the
thickest or, at minimum, equal
to the top layer (e.g., 3" [75 mm]
bottom and 3" [75 mm] top).
• Lay successive layers of
insulation unbonded or
unadhered.
• Stagger or offset all joints from
those of the underlying layer.
Installation Notes
Protect insulation from physi-
cal damage.
Handle boards carefully to pre-
vent damage during installation.
Always wear protective eyewear
and gloves when handling and
cutting insulation.
Do not leave STYROFOAM™
Brand Extruded Polystyrene
Foam Insulation exposed to
direct sunlight for more than
90 days. Consult a Dow repre-
sentative if exposure is expected
to be longer than 90 days.
Prolonged exposure to ultravio-
let radiation may cause the sur-
face of STYROFOAM™ Brand
Extruded Polystyrene Foam
Insulation to become faded and
dusty. The surface degradation
will have no measurable effect
on the insulating value of the
plastic foam unless the deterio-
ration is allowed to continue
until actual foam thickness is
lost. Since the dust would
impair the performance of adhe-
sives and finishes, dusty surfaces
should be brushed off before
these products are applied. A
light-colored, opaque protective
covering should be used if
excessive solar exposure is
expected. When stored out-
doors, keep insulation boards
tarped or covered to protect
from weather and weighted
down to prevent boards from
being blown around by the
wind. Store above standing
water.
Always check the compatibility
with other products that may
come in direct contact with the
insulation, particularly those
containing solvents. Preventive
care must be taken, such as
allowing the solvents to evapo-
rate, providing a slip sheet or
painting the surface of the insu-
lation with white latex paint.
Always brush off any surface
dust before applying white latex
paint on the insulation.
STYROFOAM ™ Brand Extruded
Polystyrene Foam Insulation is
combustible and may constitute
a fire hazard if improperly used
or installed. The insulation con-
tains a flame-retardant additive
to help inhibit ignition from
small fire sources. During ship-
ping, storage, installation and
use, this material should not be
exposed to open flames or other
ignition sources.