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Carlisle SynTec InsulBase 0.5 in. 4 ft x 4 ft Grade-II (20 psi) Polyiso Roof Insulation
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Carlisle SynTec InsulBase 0.5 in. 4 ft x 4 ft Grade-II (20 psi) Polyiso Roof Insulation
Carlisle SynTec InsulBase Grade-II rigid polyisocyanurate roof insulation board, 0.5 in. thick and 4 ft x 4 ft, rated 20 psi. Each board has a closed-cell polyiso core bonded to glass-reinforced felt facers, with a dark GRF side for ReadyFlash adhesive control. Pairs with Carlisle single-ply membrane systems.
Key Features:
- Rigid polyiso core: Closed-cell polyisocyanurate foam core bonded on each side to glass-reinforced felt facers.
- ReadyFlash technology: Dark GRF on one side and light GRF on the other lets contractors control membrane adhesive flash-off times.
- 20 psi compressive strength: Grade-II (20 psi) board suitable for standard low-slope roof assemblies.
- High R per inch: Polyiso provides the highest R-value per inch of commercially available insulation products.
- Steel deck approved: Approved for direct application to steel decks.
- Eco-friendly formulation: Zero ozone-depleting components; HFC- and HCFC-free formulation.
- Broad approvals: ASTM C1289 Type II Class 1 Grade 2; FM Class 1; UL Classified; IBC 2603; Florida Building Code approved.
Specifications Table:
| Specification | Details |
|---|---|
| Brand | Carlisle SynTec |
| Manufacturer model | 323588 |
| Sell unit | 1 board, 0.5 in. x 4 ft x 4 ft |
| Product line | InsulBase |
| Material | Polyisocyanurate (polyiso) foam with glass-reinforced felt (GRF) facers |
| Color | Tan |
| Dimensions | 4 ft x 4 ft, 0.5 in. thick |
| Thickness | 0.5 in. |
| Coverage per unit | 16 sq ft per board |
| Compressive strength | 20 psi (Grade II) |
| Standard | ASTM C1289, Type II, Class 1, Grade 2 |
| Approvals | IBC Section 2603; UL 790; UL 263; UL 1256; FM 4450/4470 Class 1; Title 24; PIMA Quality Mark; CAN/ULC S704 Type 2 & 3 Class 3; Florida Building Code; CDPH Compliant; UL Classified; LEED |
| Weight | 5.7 lb per board |
| Intended use | Low-slope commercial roof insulation under membrane |
Coverage & How Much You Need:
Each 4 ft x 4 ft board covers 16 sq ft of roof deck. Divide the roof area by 16 sq ft per board, then layer thicknesses as specified by the roof assembly design; boards sold individually.
Fit and Compatibility:
Designed for Carlisle low-slope roofing systems under Carlisle single-ply membranes (EPDM, TPO) with Carlisle adhesives and fasteners. ReadyFlash GRF facers let you choose which side receives membrane adhesives; membrane, adhesives and fastening plates sold separately.
Frequently Asked Questions (FAQ):
Q: What is included?
A: One 0.5 in. x 4 ft x 4 ft InsulBase Grade-II (20 psi) polyiso board; sold per piece.
Q: How many boards cover a square (100 sq ft)?
A: Each board covers 16 sq ft, so a roof square requires roughly 7 boards plus cutting waste.
Q: What is ReadyFlash?
A: InsulBase has a dark glass-reinforced felt on one side and light GRF on the other, letting the contractor pick which side receives membrane adhesive to manage flash-off times.
Q: Can it go directly on a steel deck?
A: Yes, InsulBase is approved for direct application to steel decks.
Q: What standards does it meet?
A: ASTM C1289 Type II Class 1 Grade 2, plus UL 790/263/1256, FM 4450/4470 Class 1, IBC 2603 and Florida Building Code approvals.
Q: What is the compressive strength?
A: This Grade-II board is rated 20 psi.
Expert Verdict — Reviewed by the SuperArbor Pro Desk
InsulBase is the workhorse tapered and flat polyiso for low-slope Carlisle membrane roofs; use 20 psi Grade-II where typical membrane systems call for it, and step up to higher grades under heavy load paths. Layer multiple 0.5 in. boards to reach the assembly R-value specified by code and energy code. Always follow the roof assembly design and Carlisle installation instructions for attachment method.
Follow the roof assembly design, manufacturer installation instructions and local building codes; use proper roof-edge fall protection when working on low-slope roofs.
Order Carlisle SynTec InsulBase 0.5 in. 20 psi polyiso boards for your low-slope roofing project.
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