Johns Manville ENRGY 3 3.25 in. x 4 ft x 4 ft Polyiso Roof Insulation Board, Grade II (20 psi)

This Johns Manville ENRGY 3 board is a 3.25 in. thick, 4 ft x 4 ft Grade-II flat polyiso roof insulation with a closed-cell foam core and glass-reinforced facers. One board is one sell unit covering 16 sq ft. It installs with mechanical fasteners, urethane adhesive or hot asphalt under JM roofing systems.

Key Features:

• High R-Value Core: The closed-cell polyisocyanurate foam core provides high R-value per inch.
• Glass-Reinforced Facers: Glass-reinforced facers add rigidity and resistance to indentation and crushing.
• Steel Deck Approved: Approved for direct application to steel decks.
• 20 psi Grade II: Meets ASTM C1289, Type II, Class 1, Grade 2 (20 psi compressive resistance).
• System Compatible: Compatible with BUR, modified bitumen and single-ply (TPO, PVC, EPDM) systems.
• Broad Approvals: UL Classified, FM approved, Miami-Dade and Florida Building Code approved, and PIMA QualityMark certified.
• LTTR 18.9: The 3.25 in. thickness has an LTTR value of 18.9 (hr-ft2-F)/BTU per the JM data sheet.

Specifications Table:

Coverage & How Much You Need:

Each 4 ft x 4 ft board covers 16 square feet of roof deck; divide total roof area by 16 to size board quantities.

Fit and Compatibility:

For use in approved JM Peak Advantage roofing guarantees; compatible with JM single-ply (TPO, PVC, EPDM) and multi-ply (BUR, APP, SBS) systems installed mechanically fastened, adhered with urethane adhesive, or with hot asphalt. Fasteners, adhesives and membranes are sold separately.

Frequently Asked Questions (FAQ):

Q: What is included in one order?
A: One 3.25 in. thick, 4 ft x 4 ft ENRGY 3 Grade-II polyiso roof insulation board.

Q: How many boards do I need?
A: Each 4 ft x 4 ft board covers 16 square feet, so divide roof area by 16 and add for waste.

Q: How is this board attached?
A: It can be mechanically fastened, set in urethane adhesive, or installed with hot asphalt per JM application instructions.

Q: What R-value does the 3.25 in. thickness provide?
A: The JM data sheet lists an LTTR value of 18.9 (hr-ft2-F)/BTU for the 3.25 in. thickness; ultimate R-value depends on installation circumstances.

Q: Can it go directly on a steel deck?
A: Yes, ENRGY 3 is approved for direct application to steel decks.

Q: Is it compatible with single-ply membranes?
A: Yes, it is compatible with TPO, PVC and EPDM systems as well as BUR and modified bitumen.

Expert Verdict Reviewed by the SuperArbor Pro Desk

ENRGY 3 Grade 2 is the standard 20 psi polyiso used under JM single-ply and multi-ply systems, and the 3.25 in. thickness is a common mid-tier choice for assemblies balancing R-value against fastener lengths. Follow JM’s minimum pre-securement patterns when the board sits under a mechanically fastened membrane, and confirm membrane fastener counts with a JM technical specialist. Size flute spans on metal decks per the data sheet before install.

Follow Johns Manville application instructions, the product Safety Data Sheet, and local code for attachment, and use fall protection when working on the roof.

Order Johns Manville ENRGY 3 3.25 in. polyiso insulation boards for your commercial roof assembly.