About the Closed Cell Foam
Caddis Insulation uses the Gaco Western Wallfoam 173.  It has an R value of 6.3 per inch of
thickness.  It increases the structural integrity of the building and is a complete air and water

Gaco Western WallFoam 173 is an HFC blown (zero-ozone depleting) liquid spray system that
cures to a low-density rigid polyurethane insulation material. WallFoam 173 contains material
derived from naturally renewable resources and does not contain CFC’s, HCFC’s or other
gases harmful to the environment. This system can be sprayed on clean dry substrates down
to 40°F (1.66°C). Refer to the Gaco Western General Instructions, SG-GacoFoam for spraying
instructions. Gaco WallFoam 173 is a Class I fire rated foam.

To ensure optimum performance a minimum pass thickness of 3/4” (1.9 cm) is
recommended with the maximum not to exceed 2” (5.1 cm) per pass. For typical equipment
settings, consult Gaco Western's GacoFoam Spray Guide.

Property Test Temp. ASTM Test Unit Value
Nominal Density: Sprayed-in-Place 77°F (25°C) D-1622-93  lbs/ft³ 1.6 – 1.8  
R Value:   
C-518 R 6.3
Compressive Strength: Parallel to Rise 77°F (25°C) D-1621-94 psi 24.5  
Tensile Strength  77°F (25°C) D-1623  psi 44.1  
Dimensional Stability: (28 Day) 158°F (70°C) 97% RH (14 days)

-20.2°F (-29°C) Amb. RH (24 Hours)
D-2126-94 % Vol change -11.47

Recommended Service Temperature Range   °F -40°F (-4.4°C) to 200°F (93°C)

Closed Cell Content 77°F (25°C) D-2856C-94 % 90.0  
Water Vapor Transmission
77°F (25°C)  E-96-95  Perm-inch  2.0  

Fire Testing:
WallFoam 173 has passed burn testing per ASTM E-84 and received a Flame Spread Index
(FSI) of 25 and a Smoke Developed Index (SDI) of 450 at 4 inch thickness.

"A" Component contains polymeric isocyanate. "B" Component contains polyol, catalysts
and blowing agents.

Property Test Temp. ASTM Test Unit Value
Viscosity "A" Component 77°F
(25°C) D-2196-68  cps  180 ± 20

Viscosity "B" Component 77°F
(25°C) D-2196-68  cps 400 ± 50  
Specific Gravity "A" Component 77°F
(25°C) D-1638-70  1.22

Specific Gravity "B" Component 77°F
(25°C) D-1638-70  1.19  
Weight/Gallon "A" Component 77°F
(25°C)  lbs/gal 10.2
Weight/Gallon "B" Component 77°F
(25°C)  lbs/gal 9.9
Mixing Ratio:"A" & "B" Component 77°F
(25°C)  by volume 1:1  
Stability: When stored at 50°F to 70°F
(10° - 21°C)"A" & "B" Component    A:

1 Year

3 Months

Two Pound Closed Cell
Closed Cell