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Carlisle SynTec InsulBase Grade-II 3.3 in. x 4 ft x 8 ft Polyiso Roof Insulation Panel
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Carlisle SynTec InsulBase Grade-II 3.3 in. x 4 ft x 8 ft Polyiso Roof Insulation Panel
This is a Carlisle SynTec InsulBase Grade-II (20 psi) rigid polyisocyanurate roof insulation panel, 3.3 in. thick and 4 ft x 8 ft. A closed-cell polyiso core is bonded on each side to glass-reinforced felt facers, and one panel is sold per unit. It installs under Carlisle SynTec single-ply membrane roofing systems.
Key Features:
- High compressive strength: Grade-II polyiso rated for 20 psi compressive strength.
- Closed-cell core: Closed-cell polyisocyanurate foam core bonded to glass-reinforced felt (GRF) facers on both sides.
- Code-listed: Meets ASTM C1289, Type II, Class 1, Grade 2 and IBC Section 2603.
- FM Class 1: FM Standards 4450/4470 Class 1 Approval for commercial roof assemblies.
- UL listed: UL 790, UL 263 and UL 1256 listed; UL Classified.
- Energy code ready: California Title 24, Florida Building Code Approved, CDPH Compliant and PIMA Quality Mark Approved.
- Standard board size: 4 ft x 8 ft board covers 32 sq ft for fast installs on open decks.
Specifications Table:
| Specification | Details |
|---|---|
| Brand | Carlisle SynTec |
| Manufacturer model | 306084 |
| Sell unit | 1 panel, 3.3 in. x 4 ft x 8 ft |
| Product line | InsulBase |
| Material | Polyisocyanurate (polyiso) foam with glass-reinforced felt (GRF) facers |
| Dimensions | 3.3 in. thick x 4 ft x 8 ft |
| Nominal size | 4 ft x 8 ft |
| Thickness | 3.3 in. |
| Grade / rating | Grade-II (20 psi), ASTM C1289 Type II, Class 1, Grade 2 |
| Approvals | IBC Section 2603; UL 790; UL 263; UL 1256; FM 4450/4470 Class 1; California Title 24; PIMA Quality Mark; CAN/ULC S704 Type 2 & 3, Class 3; Florida Building Code Approved; CDPH Compliant; LEED |
| Weight | 20.256 lb per panel |
| Intended use | Rigid roof insulation for commercial low-slope roofing assemblies |
| Pack quantity | 1 panel |
Coverage & How Much You Need:
One 4 ft x 8 ft panel covers 32 sq ft of roof area before layout waste. Divide the roof square footage by 32 to estimate panel count and add a waste allowance for cuts and perimeter fitting.
Fit and Compatibility:
InsulBase polyiso installs within Carlisle SynTec commercial roofing systems under the membrane, per the specified attachment method. Membrane, adhesives, fasteners/plates and cover boards are sold separately.
Frequently Asked Questions (FAQ):
Q: What is included in one unit?
A: One 3.3 in. thick, 4 ft x 8 ft InsulBase Grade-II (20 psi) polyiso insulation panel.
Q: How much does one panel cover?
A: One 4 ft x 8 ft panel covers 32 sq ft before waste; divide your roof area by 32 and add a cut-waste allowance.
Q: What does Grade-II (20 psi) mean?
A: It is the compressive strength grade under ASTM C1289, Type II, Class 1, Grade 2, appropriate for standard low-slope roofing applications.
Q: What facers does it have?
A: The closed-cell polyiso core is bonded on each side to glass-reinforced felt (GRF) facers.
Q: Is it code approved?
A: Yes: ASTM C1289 Type II Class 1 Grade 2, IBC Section 2603, UL listings, FM Class 1, plus Florida Building Code and California Title 24 approvals.
Q: What should I pair it with?
A: Pair with Carlisle SynTec membranes, fasteners/plates, cover boards and adhesives per the roofing system specification.
Expert Verdict — Reviewed by the SuperArbor Pro Desk
The 3.3 in. thickness is commonly used in multi-layer insulation build-ups where higher R-value per board is needed while maintaining a 20 psi Grade-II rating. Keep joints staggered between layers and confirm the attachment pattern with the Carlisle SynTec system specification. Verify required R-value and thermal barrier requirements with local code before ordering.
Follow the manufacturer's installation instructions and local building and fire codes, and use proper lifting technique and fall protection when moving large rigid insulation boards on a roof.
Order the Carlisle SynTec InsulBase 3.3 in. 4 ft x 8 ft Grade-II polyiso panel for high R-value roof insulation.
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