Dow Thermax Sheathing is a high-performance polyiso insulation panel designed for Class A fire-rated assemblies, offering excellent moisture protection for both concealed and exposed applications above and below grade. This 4' x 8' panel is built to perform in residential and commercial projects that demand reliable thermal performance and superior moisture control.

Key Features & Design

• Fire rating: Class A fire rating with reinforcing facers and chemical modifications that contribute to fire resistance and dimensional stability, making it well-suited for hourly rated assemblies.
• Facing: Nominal 1.0 mil, smooth aluminum foil facers on both sides for durability and moisture resistance.
• Size and insulation values: 4' x 8' panels available in thicknesses that deliver the following R-values: 0.5" R3 (32 sq ft/board); 1" R6 (32 sq ft/board); 1.5" R10 (32 sq ft/board); 2" R13 (32 sq ft/board).
• Moisture protection: Effectively reduces condensation for exceptional moisture control in challenging environments.
• Interior exposure: Can be installed exposed to the interior without a thermal barrier, simplifying installation in specific applications.
• Applications: Ideal for residential and commercial walls, interior basement walls, residential closed (non-vented) crawl spaces, and interior walls of metal buildings.

Related Products

• Rmax Thermasheath-3 Polyiso Rigid Foam Insulation Board — foil-faced on both sides for enhanced thermal performance, available in various thicknesses.
• Rmax Durasheath-3 Insulation Board — reinforced aluminum foil facing on one side for durability, available in various thicknesses.