THERMAX™ Sheathing is a non-structural, rigid board insulation consisting of a glass-fiber-reinforced polyisocyanurate foam core laminated between 1.0 mil smooth, reflective aluminum foil facers on both sides. The reinforcement, along with chemical modifications, contributes to fire resistance and dimensional stability. THERMAX™ Sheathing can be installed exposed to the interior without a thermal barrier and is especially appropriate for hourly rated assemblies.
Building Code Compliance
Complies with ASTM C1289 Type I, Class 2. Meets IBC/IRC requirements for foam plastic insulation. See ICC-ES ESR-1659. FM 4880 – see Factory Mutual Approval Guide. UL Classified. Calif. Std. Reg. # CA T383. Miami-Dade NOA 08.0320.01 DOT Docket 90 Mass Transit Vehicle Insulation.
THERMAX™ Sheathing consists of a high-performance foam core laminated between 1.0 mil smooth, reflective aluminum foil facers on both sides that contribute to fire resistance and dimensional stability.
|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 9' / 4' x 10'||Square Edge||25|
|.75||5.0||4' x 8' / 4' x 9' / 4' x 10'||Square Edge||25|
|1.0||6.5||4' x 8' / 4' x 9' / 4' x 10'||Square Edge||25|
|1.50||9.8||4' x 8' / 4' x 9' / 4' x 10'||Square Edge, Shiplap||25|
|2.0||13.0||4' x 8' / 4' x 9' / 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 Group for information on different R-values.
(4) Vertical compressive strength is measured at 10% deformation or at yield, whichever occurs first.