Skip to content
Johns Manville ENRGY 3 Tapered Polyiso Insulation Board 1/2 in. Q Taper 4 ft. x 4 ft.
Regular price $28.24Orders start at $399 — combine any items to reach the minimum. Learn more
Johns Manville ENRGY 3 Tapered Polyiso Insulation Board 1/2 in. Q Taper 4 ft. x 4 ft.
This is Johns Manville ENRGY 3 tapered polyisocyanurate insulation board, a 1/2 inch Q taper panel in a 4 ft. x 4 ft. sheet, gray. Each order unit is one sheet covering a 0.5 inch to 2.5 inch thickness range across the taper. Use it to build slope in low-slope roof assemblies before cover board and membrane.
Key Features:
- Tapered for slope: The 1/2 in. Q taper ranges from 0.5 in. to 2.5 in. thickness across the panel to create positive roof drainage.
- Polyiso core: Rigid polyisocyanurate foam insulation board for low-slope roof assemblies.
- 4 ft. x 4 ft. panel: Ships as a 4 ft. x 4 ft. tapered sheet.
- Gray board: The listed panel is gray.
- ENRGY 3 series: Part of the Johns Manville ENRGY 3 tapered insulation line.
Specifications Table:
| Specification | Details |
|---|---|
| Brand | Johns Manville |
| Sell unit | 1 sheet, 4 ft. x 4 ft., 1/2 in. Q taper |
| Product line | Johns Manville ENRGY 3 Tapered Polyiso Insulation Board |
| Available colors | Gray |
| Available sizes | 1/2 in. Q taper, 4 ft. x 4 ft. (0.5 in. to 2.5 in. thickness range) |
| Material | Polyisocyanurate foam |
| Dimensions | 4 ft. x 4 ft. sheet |
| Thickness | 0.5 in. to 2.5 in. (1/2 in. Q taper) |
| Nominal size | 4 ft. x 4 ft., 1/2 in. Q taper |
| Intended use | Tapered rigid insulation to create slope in low-slope roofing |
| Pack quantity | 1 sheet |
Coverage & How Much You Need:
One 4 ft. x 4 ft. sheet covers 16 square feet. Tapered systems are laid out per a slope plan, so map panels by quarter taper and slope direction before ordering; sheet count equals roof area divided by 16 sq. ft. plus waste.
Fit and Compatibility:
Used in Johns Manville and compatible low-slope roof assemblies, typically layered under a cover board and membrane. Tapered layouts require a slope plan; moppers, fasteners and cover board are sold separately.
Frequently Asked Questions (FAQ):
Q: What taper is this panel?
A: The listed item is a 1/2 inch Q taper, running from 0.5 inch to 2.5 inch thickness across the 4 ft. x 4 ft. panel.
Q: What color is it?
A: The listed panel is gray.
Q: How much area does one sheet cover?
A: One 4 ft. x 4 ft. sheet covers 16 square feet before waste.
Q: What is a Q taper?
A: Taper designations describe the panel's slope and thickness range; confirm the exact slope per foot with the manufacturer's tapered layout plan.
Q: Do I need cover board over it?
A: Tapered polyiso is typically covered with a cover board or directly by membrane per the roof assembly design; attachment materials are sold separately.
Expert Verdict — Reviewed by the SuperArbor Pro Desk
Tapered polyiso is how you build drainage into a dead-flat or under-sloped deck, and quarter taper panels like this 1/2 in. Q are the backbone of most crickets and sump layouts. Order from a tapered layout plan so panel thicknesses and slopes land where the design intends, and keep the thinnest edge thickness consistent with the insulation code requirement. Pair with a cover board where membrane puncture resistance matters.
Verify the finished assembly meets local insulation R-value and fire requirements, and handle large foam panels carefully on the roof to avoid falls and wind damage.
Plan your slope with Johns Manville ENRGY 3 1/2 in. Q tapered polyiso insulation boards.
All third party trademarks, including logos and icons, referenced on our website and product pages remain the property of their respective owners. Unless specifically identified as such, Arbor's use of third party trademarks does not indicate any relationship, affiliation, sponsorship, or endorsement between Arbor Home and the owners of these trademarks. Any references by Arbor Home to third party trademarks are to identify the corresponding third party goods.
