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Carlisle SynTec InsulBase Grade-II 1.8 in. x 4 ft x 8 ft Polyiso Roof Insulation Panel
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Carlisle SynTec InsulBase Grade-II 1.8 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, 1.8 in. thick and 4 ft x 8 ft. The closed-cell polyiso core is bonded on each side to glass-reinforced felt facers, with one panel per sell unit. It is intended for use beneath Carlisle SynTec single-ply membrane roof systems.
Key Features:
- 20 psi 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.
- Light handling: 1.8 in. thickness at about 12.4 lb per board keeps handling easy on the deck.
Specifications Table:
| Specification | Details |
|---|---|
| Brand | Carlisle SynTec |
| Manufacturer model | 323376 |
| Sell unit | 1 panel, 1.8 in. x 4 ft x 8 ft |
| Product line | InsulBase |
| Material | Polyisocyanurate (polyiso) foam with glass-reinforced felt (GRF) facers |
| Dimensions | 1.8 in. thick x 4 ft x 8 ft |
| Nominal size | 4 ft x 8 ft |
| Thickness | 1.8 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 | 12.448 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 area by 32 to estimate panel count and add a waste allowance for cuts.
Fit and Compatibility:
InsulBase polyiso installs within Carlisle SynTec commercial roofing systems under the membrane per the specified attachment. Membrane, adhesives, fasteners/plates and cover boards are sold separately.
Frequently Asked Questions (FAQ):
Q: What is included in one unit?
A: One 1.8 in. thick, 4 ft x 8 ft InsulBase Grade-II (20 psi) polyiso insulation panel.
Q: How much does one panel cover?
A: One panel covers 32 sq ft; divide your roof square footage 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, suited to standard low-slope roof assemblies.
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, cover boards, fasteners/plates and adhesives per the roofing system specification.
Expert Verdict — Reviewed by the SuperArbor Pro Desk
The 1.8 in. board is a good base or intermediate layer in multi-layer InsulBase build-ups where the total insulation thickness is achieved with several boards. Stagger joints between layers and follow the Carlisle SynTec fastening specification for the deck type. Confirm the project R-value target and local code requirements before ordering.
Follow the manufacturer's installation instructions and local building and fire codes, and use fall protection and safe lifting practices when handling rigid insulation on a roof.
Order the Carlisle SynTec InsulBase 1.8 in. 4 ft x 8 ft Grade-II polyiso panel for your roof insulation layers.
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