GAF EnergyGuard 2.6 in. x 4 ft. x 8 ft. Grade-II (20 psi) Polyiso Roof Insulation Panel

This is a GAF EnergyGuard 2.6 in. polyisocyanurate roof insulation panel, 4 ft x 8 ft, Grade-II (20 psi) with glass fiber reinforced cellulosic felt facers bonded to a polyiso foam core. Each panel provides 32 sq ft of coverage and ships as a single piece. It pairs with GAF single-ply, mod bit and BUR roof systems, including tapered designs.

Key Features:

• High thermal value: Polyisocyanurate foam core with glass fiber reinforced cellulosic felt facers delivers high thermal efficiency for low-slope roofs.
• 20 psi compressive strength: ASTM C1289 Type II, Class 1 Grade 2 rating provides 20 psi compressive strength.
• Thicker R-value: The 2.6 in. thickness provides greater thermal resistance per panel than standard 1-2 in. polyiso.
• System approvals: Approved for use in mod bit, BUR and single-ply systems with FM 4450/4470 and UL listings.
• Membrane compatible: Compatible with TPO and PVC membranes in adhered, mechanically attached and induction welded systems.
• Easy handling: Lightweight panels are easy to cut in the field for faster installation.
• Green building credit: Green Circle Certified for recycled content and contributes to green building rating systems.

Specifications Table:

Coverage & How Much You Need:

One panel covers 32 sq ft (4 ft x 8 ft). Bundles of 18 pieces cover 576 sq ft, so a 1,000 sq ft roof area needs roughly 32 panels. In tapered systems, panel count and slope layout should follow a tapered design plan.

Fit and Compatibility:

Compatible with GAF single-ply (TPO and PVC), modified bitumen and BUR roof systems in adhered, mechanically attached and induction welded applications. Membrane, adhesives and fasteners are sold separately; a cover board is required for UL Class A over combustible decks.

Frequently Asked Questions (FAQ):

Q: What is included in this order?
A: One 2.6 in. thick, 4 ft x 8 ft EnergyGuard Grade-II (20 psi) polyiso insulation panel. Bundles ship 18 pieces covering 576 sq ft.

Q: How much area does one panel cover?
A: Each panel covers 32 sq ft; a full 18-piece bundle covers 576 sq ft.

Q: Which membrane systems is it compatible with?
A: It is approved for mod bit, BUR and single-ply systems, and works with TPO and PVC in adhered, mechanically attached and induction welded assemblies.

Q: What is the compressive strength?
A: This panel is ASTM C1289 Type II, Class 1 Grade 2, rated at 20 psi.

Q: Is a cover board required?
A: For UL Class A over combustible decks, a cover board is required per GAF's listing notes.

Q: How many panels do I need per square?
A: One roofing square (100 sq ft) requires just over 3 panels, so plan about 32 panels per 1,000 sq ft.

Expert Verdict — Reviewed by the SuperArbor Pro Desk

At 2.6 in., this panel stacks significant R-value in a single layer, reducing seams and labor compared with multiple thinner lifts. Verify the deck can accept fastener penetrations of this length and confirm uplift requirements with the membrane manufacturer. For roofs with ponding issues, combine flat panels like this with EnergyGuard tapered panels or crickets to establish positive drainage.

Install per GAF's instructions and local building code, and use fall protection when working on low-slope roofs.

Order the GAF EnergyGuard 2.6 in. polyiso roof insulation panel for your next low-slope roofing project.