THERMAX™ Heavy Duty Insulation (U.S. Only)

A glass-fiber reinforced polyisocyanurate foam insulation faced with 4.0 mil embossed white thermoset-coated aluminum on one side and 1.25 mil embossed aluminum on the other side.

Used In

  • Insulation/interior finish system for walls and ceilings in metal, wood post frame and concrete or masonry buildings
  • For use in moderate-impact areas

Product Advantages

  • Can be installed exposed to the interior without a thermal barrier
  • Can be pressure-washed up to 2,000 psi with a 15-degree or greater spray tip (at minimum 3' distance)

Typical Physical Properties

These properties are typical but do not constitute specifications.

THERMAX™ Heavy Duty Insulation - U.S. Commercial Only

Nominal Board Thickness(1), in R-Value(2)(3) Board Size, ft Edge Treatment Min Compressive Strength(4), psi
.50 3.3 4 x 8 / 4 x 10 Square Edge 25
.75 5.0 4 x 8 / 4 x 10 Square Edge 25
1.0 6.5 4 x 8 / 4 x 10 Square Edge 25
1.5 9.8 4 x 8 / 4 x 10 Square Edge/Shiplap 25
2.0 13.0 4 x 8 / 4 x 10 Square Edge/Shiplap 25

(1) Not all product sizes are available in all regions.

(2) R means resistance to heat flow. The higher the R-value, the greater the insulating power. R-values are expressed in ft2• h•°F/Btu. R-value determined by ASTM C518.

(3) Consult your Dow Seller or Technical service Rep for information on different R-values

(4) Vertical compressive strength is measured at 10% deformation or yield, whichever occurs first. Since Dow polyisocyanurate insulation is a visco-elastic material, adequate design safety factors should be used to prevent long-term creep. For static loads, 3:1 is suggested. For dynamic loads, 5:1 is suggested.

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