TRI-BUILT 2.6 in. x 4 ft. x 8 ft. ISO II GRF Polyiso Roof Insulation Board

This TRI-BUILT ISO II GRF roof insulation board is a 2.6-inch-thick, 4 ft. x 8 ft. polyisocyanurate panel offering increased thermal value in low-slope roof assemblies. One board covers 32 sq ft and is sold per piece.

Key Features:

• 2.6 in. thickness: Thicker panel delivers more thermal resistance per layer.
• 4 ft. x 8 ft. board: Standard 32 sq ft board size for efficient layout.
• GRF facer: Glass-reinforced facer in the ISO II line.
• Polyiso core: Polyisocyanurate foam insulation for low-slope roofing systems.
• Manageable weight: Approximately 14.75 lb per board for practical job-site handling.

Specifications Table:

Coverage & How Much You Need:

Each 2.6 in. x 4 ft. x 8 ft. board covers 32 sq ft. Divide the roof area by 32 and allow for cuts and waste; boards are also counted by the square (100 sq ft).

Fit and Compatibility:

Used in low-slope roof assemblies beneath approved membranes and often paired with thinner ISO layers. Fastening plates and adhesives are sold separately; install per the membrane manufacturer’s requirements.

Frequently Asked Questions (FAQ):

Q: What size is each board?
A: Each board is 4 ft. x 8 ft. and 2.6 inches thick, covering 32 sq ft.

Q: How many boards do I need?
A: Divide the roof area by 32 sq ft per board and allow for waste and cuts.

Q: What is GRF?
A: GRF refers to the glass-reinforced facer on this ISO II board.

Q: How much does a board weigh?
A: Approximately 14.75 lb per 2.6-inch board.

Q: Why choose 2.6 in. thickness?
A: It provides more thermal resistance per layer than thinner boards in the same ISO II line.

Expert Verdict Reviewed by the SuperArbor Pro Desk

Thicker polyiso lifts reduce the number of layers needed to hit a target R-value; verify the board’s long-term thermal resistance and attachment with the membrane manufacturer. Use staggered joints across layers where multiple lifts are specified. Store boards flat, dry and protected until installed.

Handle thick boards with care on windy rooftops and keep them flat and secured until fastened.

Order the TRI-BUILT 2.6 in. ISO II GRF polyiso roof insulation board for higher thermal value per layer.