Elevate ISO 95+ GL Grade-II (20 psi) Polyiso Roof Insulation Board, 3.5 in. x 4 ft. x 4 ft.

This Elevate ISO 95+ GL Grade-II polyisocyanurate roof insulation board measures 3.5 in. thick, 4 ft. x 4 ft., and carries a 20 psi Grade-II compressive rating. The closed-cell polyiso core is laminated to glass-reinforced mat facers on both faces. Sold per piece; order 9 boards per square (100 sq ft).

Key Features:

• Maximum R-value: Polyiso delivers the highest R-value per inch of common rigid insulation systems, a smart investment for the building.
• Thick single layer: At 3.5 in. thick, fewer layers may be needed to reach design R-value compared with thinner boards.
• Grade-II 20 psi: Grade-II compressive strength rated at 20 psi for commercial low-slope roof assemblies.
• Glass-reinforced facers: A closed-cell polyiso foam core is laminated to a glass reinforced mat facer on both major surfaces.
• Thermal stability: ISOGARD polyiso meets both ASTM C1289 required and recommended thermal performance values.
• Odor-free blowing agent: Uses an HCFC-free, EPA accepted blowing agent that does not contribute to ozone depletion (ODP-free).
• Widely certified: ASTM C1289 Type II Class 1, FM Approved, UL Classified, and Miami-Dade County Approved.

Specifications Table:

Coverage & How Much You Need:

One 4 ft x 4 ft board covers 16 sq ft of roof deck. For one roofing square (100 sq ft), plan on 9 boards (144 sq ft) allowing for field cuts and staggered joints.

Fit and Compatibility:

Designed for use in Elevate low-slope commercial roof systems under single-ply and other approved membranes, installed per Elevate specifications. Other thicknesses, tapered ISOGARD GL, and attachment adhesives or fasteners are sold separately.

Frequently Asked Questions (FAQ):

Q: How many boards cover 100 sq ft?
A: Each 4 ft x 4 ft board covers 16 sq ft, so 9 boards give 144 sq ft, enough for one square with cutting waste.

Q: How is a 3.5 in. board attached?
A: Install per Elevate specifications using approved low-rise adhesives or mechanical fasteners designed for thick polyiso; thick boards typically benefit from two-layer staggered installation.

Q: What is the compressive rating?
A: Grade-II polyiso is rated 20 psi compressive strength under the ASTM C1289 Type II classification.

Q: What facers are on the board?
A: A glass-reinforced mat facer is laminated to both major surfaces of the closed-cell foam core.

Q: Does it contain ozone-depleting blowing agents?
A: No. It uses an HCFC-free, EPA accepted blowing agent that does not contribute to ozone depletion (ODP-free).

Expert Verdict — Reviewed by the SuperArbor Pro Desk

Use 3.5 in. Grade-II where the design calls for a thick base layer of polyiso without stacking thin boards. Stagger board joints between layers, keep joints tight, and confirm attachment density against the project wind-uplift requirement. For code compliance, always use the LTTR/aged R-value printed on the board label, not the nominal R-value.

Lift thick boards with care and wear gloves, eye protection and a dust mask when field-cutting polyiso.

Order the Elevate ISO 95+ GL 3.5 in. polyiso roof insulation board for high R-value in fewer layers.