Dow THERMAX™ Wall System - Manual (Page 3)

I N S T A L L A T I O N I N F O R M A T I O N . C O M M E R C I A L
while applying the foam.
• Spray equipment must be capable
of delivering the proper ratio
(1:1 by volume) of polymeric
isocyanate and polyol blend at
the recommended temperatures
and spray pressures (Table 1).
To minimize the potential for
off-ratio product, the use of a
common drive on the positive
displacement pumps of the
proportioner is recommended.
• Follow the spray equipment
manufacturer’s guidelines for
all spray operations. Spray units
and guns come in a variety of
capacities and styles and will
require adjustments to achieve
the desired spray pattern.
AMBIENT AND SUBSTRATE
CONDITIONS
Substrate must be at least 5 degrees
above dew point, with best process-
ing results when the relative humidity
is below 80 percent (<18 percent
substrate moisture content if wood or
concrete is the substrate). To minimize
potential for moisture interference with
adhesion of STYROFOAM
™ Brand
SPF (CM Series) to the substrate, spray
only when the relative humidity is
below 70 percent (<12 percent substrate
moisture content if wood or concrete
is the substrate).
SURFACE PREPARATION
• The steel stud and THERMAX ™ (ci)
Exterior Insulation substrates
must be free of moisture (dew or
frost), grease, oil, solvents and
other materials that would
adversely affect the adhesion of
the polyurethane foam. Poor
adhesion will result in stud line
cracking of the SPF.
• THERMAX ™ (ci) Exterior Insulation
and the steel studs do not need
to be primed unless the studs are
weathered or previously painted.
If priming is desired, clean the
surface per primer manufacturer’s
recommendations and use a
primer known to be compatible
with spray polyurethane foam.
• Most untreated and unpainted wood
does not need to be primed.
• Substrate temperatures should
not exceed 120°F for STYROFOAM ™
Brand SPF CM 2060, 100°F for
STYROFOAM
™ Brand SPF CM
2045 and 60°F for STYROFOAM ™
Brand SPF CM 2030. Excessive
temperatures will lead to fast gel
times and low yield.
APPLICATION GUIDELINES
Due to the exothermic reaction of
the isocyanate and polyol blend,
STYROFOAM
™ Brand SPF (CM
Series) should be applied in layers
1/2" to 1-1/2" thick. Application of
one layer of 1-1/2" thick is
recommended for optimum yield
and performance. Allow the foam to
cool completely before applying
successive layers. If spraying to full
cavity depth, maximum thickness
per layer is 2". Excessive
thicknesses can lead to void
formation and even internal char,
reducing the thermal and
mechanical quality of the foam.
To minimize void formation where
the sheathing is attached to the steel
studs, apply foam in the cavity where
the steel stud and sheathing meet
(picture framing technique) prior to
filling the cavity. Allow the foam to
fully cool and then spray to the desired
thickness by filling in the area between
the previously applied foam using a
side-to-side motion within each cavity.
STYROFOAM ™ Brand SPF (CM
Series) should be covered as soon as
feasible during the construction process.
There is no need to wait for any off-
gassing of the foam as this happens
immediately during application.
OVERSPRAY NOTES
Overspray can lead to several prob-
lems on the job site if not controlled
properly. Overspray will coat all
surfaces in a room and if windows
and doorways are left open, the
overspray can reach other rooms
and vehicles outside the building.
Cover objects near the application
area that might be coated with over-
spray. Excessive overspray can
accumulate on areas that are
intended for STYROFOAM™ brand
Spray Polyurethane Foam Insulation
(CM Series) application. Overspray
can be brittle and may affect the
adhesion of the STYROFOAM™
brand Spray Polyurethane Foam
Insulation (CM Series) on
oversprayed substrates. When
STYROFOAM™ brand Spray
Polyurethane Foam Insulation (CM
Series) is applied to an area coated
with excessive over-
spray, delamination can result.
To minimize overspray, do not
apply STYROFOAM ™ Brand SPF
(CM Series) if there is air movement
in the room due to wind or fans.
Point the gun perpendicular to the
surface being sprayed and as close
as possible without causing
spattering or a popcorn pattern.
COLD WEATHER APPLICATION
Applying STYROFOAM ™ Brand SPF
CM 2030 to the interior stud cavity
side of THERMAX
™ (ci) Exterior
Insulation when outside temperatures
are below 30°F can be accomplished
with the following precautions:
• Heat the area to be sprayed to
≥30°F for a minimum of 2 hours
prior to spraying for both the
ambient air and substrate
temperature. This is best done
with window and doorway areas
closed to improve even heating.
Dry off any areas that might have
formed moisture on the surface
before spraying.
• Check the substrates (sheathing
and studs) and ensure no
moisture condensation is present.
After applying the spray foam,
maintain the temperature at ≥30°F
for 48 hours.
SPF TROUBLESHOOTING TIPS (SEE
TABLE 2)
Reduced yield and excessive shrink-
age leading to stud line cracking are
the more common issues that SPF
applicators face. The best rule of
thumb is to stop applying foam to
the walls if the foam looks different.
“Different” would include color
changes, color swirls, faster/slower
than normal cream, non-circular or
smaller/larger than usual spray
pattern, foam reversion and poor
wetting of the substrate.
Recommended Equipment Relative Humidity %: <80 Substrate Temp (°F) Ambient Temp (°F)
• Graco/Gusmer A-20, E20/30, H25/40 proportioner CM 2030: 30-60 CM 2030: 30-70
or equivalent CM 2045: 45-100 CM 2045: 45-95
• Graco/Gusmer Fusion AP, MP, CS, Probler P2 gun CM 2060: 60-120 CM 2060: 60-100
or equivalent
• #0.01-0.03 mix chamber or equivalent
Difference Between Ambient and Primary Heater Temp (°F): 115-130 (1) Hose Temp (°F): 115-130 (1)
Dew Point Temperatures (°F): >5
Dynamic Pressure “A” (psi): Dynamic Pressure “B” (psi): SPF max.: 1.5" thick Mixing Ratio A/B: 1:1
600-1200 (800
(2)
) 600-1200 (800
(2)
)
TABLE 1: RECOMMENDED PROCESSING PARAMETERS – CM 2030, CM 2045 AND CM 2060
(1) To minimize potential for stud line cracking, STYROFOAM™ Brand SPF CM 2030 should be applied at the higher end of temperature and pressure ranges.
(2) Recommended initial pressure
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