TRI-BUILT 3.0 in. x 4 ft. x 8 ft. Polyiso ISO Rigid Roof Insulation Board

This TRI-BUILT ISO rigid roof insulation board is a 3.0 in. thick polyisocyanurate panel in a 4 ft. x 8 ft. sheet, sold as one piece. Its added thickness helps reach target R-value in fewer layers and it pairs with cover boards, adhesives and membrane systems in the roof build-up.

Key Features:

• Rigid polyiso core: Polyisocyanurate rigid foam board for low-slope roof insulation.
• Full 4×8 sheet: Each board measures 4 ft. x 8 ft., providing 32 sq ft of area.
• Thick 3.0 in. panel: 3.0 in. thickness builds insulation value quickly in fewer lifts.
• Manageable weight: Weighs approximately 16.5 lb per board despite the added thickness.
• Flat board format: Rigid sheet lays flat for clean joints and easy multi-layer staggering.
• Single-piece ordering: Sold per piece so quantities match the insulation layout.

Specifications Table:

Coverage & How Much You Need:

One 4 ft. x 8 ft. board covers 32 sq ft. Divide total roof area by 32 for a board count, then add for cuts and perimeter waste.

Fit and Compatibility:

Installed as rigid insulation in low-slope roof assemblies with cover boards, insulation adhesives and membranes. Attachment pattern must follow the roofing system manufacturer’s requirements and local code.

Frequently Asked Questions (FAQ):

Q: What is included in the sell unit?
A: One 3.0 in. thick, 4 ft. x 8 ft. polyiso insulation board.

Q: How many boards for my roof?
A: Each board covers 32 sq ft; divide your area by 32 and add for cut waste.

Q: How is this thickness installed?
A: Boards are mechanically fastened or adhered per the roofing system manufacturer’s instructions and local code.

Q: Can I combine it with thinner boards?
A: Yes, thick base layers are often combined with thinner lifts to reach total design thickness.

Q: How much does one board weigh?
A: Approximately 16.48 lb.

Q: Is on-site cutting possible?
A: Yes, score and cut rigid polyiso with a utility knife or insulation saw.

Expert Verdict Reviewed by the SuperArbor Pro Desk

Choosing a 3.0 in. polyiso board reduces the number of lifts needed to reach design R-value, saving labor on larger low-slope roofs. Stage boards flat, keep them dry, and stagger joints between layers. Verify fastener length and wind-uplift attachment with the membrane system manufacturer before installation.

Wear gloves, eye protection and a dust mask when cutting rigid foam, and follow the roofing system manufacturer’s installation instructions and local code.

Order TRI-BUILT 3.0 in. ISO rigid roof insulation boards to reach your design thickness in fewer lifts.