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

THERMAX™ Heavy Duty is designed as an insulation and interior finish system for walls and ceilings in metal, wood post frame, and concrete or masonry buildings, as governed by building codes.

The tough 4 mil white embossed aluminum surface of THERMAX™ Heavy Duty makes it the insulation with the most durable finish choice for use in moderate-impact areas, and it can be pressure-washed up to 2,000 psi with a 15-degree or greater spray tip (at 3' minimum distance). Maximum length is 30 ft. (9.1 m) and a maximum thickness of 3 inches (76.2 mm).

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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