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Johns Manville Vapor Barrier SAR Self-Adhering Roofing Membrane, 39-3/8 in. x 105 ft Roll
Regular price $281.50Orders start at $399 — combine any items to reach the minimum. Learn more
Johns Manville Vapor Barrier SAR Self-Adhering Roofing Membrane, 39-3/8 in. x 105 ft Roll
JM Vapor Barrier SAR is a self-adhering, tri-laminate woven polyethylene vapor barrier roll for roofing assemblies, supplied as a 39-3/8 in. x 105 ft white roll. Its self-sealing SBS rubber and asphalt layer delivers low air and vapor permeability, while the nonslip, UV-protected top surface provides up to 90 days of temporary weather protection. One roll is included per order.
Key Features:
- Self-adhering: Self-adhering modified bitumen with an easy-peel split-back silicone release film.
- Low permeability: Self-sealing SBS rubber and asphalt blend provides low air and vapor permeability.
- 90-day weather shield: Nonslip, UV-protected top surface provides temporary weather protection for 90 days.
- Puncture resistant: Tri-laminate woven polyethylene offers high tensile strength and puncture resistance.
- Dimensional stability: Fiber glass reinforcement withstands differential movement with no thermal memory, so the sheet relaxes quickly.
- Nonslip surface: Woven polyethylene top surface is nonslip for safer footing during installation.
Specifications Table:
| Specification | Details |
|---|---|
| Brand | Johns Manville |
| Sell unit | 1 roll, 39-3/8 in. x 105 ft |
| Product line | JM Vapor Barrier SAR |
| Available colors | White |
| Available sizes | 39-3/8 in. x 105 ft roll |
| Dimensions | 39-3/8 in. x 105 ft |
| Material | Tri-laminate woven polyethylene with SBS-modified bitumen and fiber glass reinforcement |
| Finish / texture | Nonslip, UV-protected white top surface |
| Coverage per unit | 39-3/8 in. x 105 ft per roll |
| Intended use | Roofing vapor barrier, commercial roofing membranes |
| Weather exposure | Temporary weather protection for 90 days |
Coverage & How Much You Need:
One roll measures 39-3/8 in. x 105 ft, yielding roughly 343 sq. ft. of material; allow for side and end laps per the project specification when estimating rolls.
Fit and Compatibility:
Part of Johns Manville commercial roofing systems as a self-adhering vapor barrier layer. It is installed beneath the roofing assembly; primers and compatible JM membranes are specified by the system design.
Frequently Asked Questions (FAQ):
Q: What size is the roll?
A: The roll is 39-3/8 in. wide by 105 ft long, in white.
Q: How is it installed?
A: Peel the split-back silicone release film and self-adhere the modified bitumen side to the prepared substrate; the fiberglass reinforcement has no thermal memory so it relaxes quickly.
Q: How long can it be exposed?
A: The UV-protected top surface provides temporary weather protection for up to 90 days.
Q: Is it puncture resistant?
A: Yes, the tri-laminate woven polyethylene construction provides high tensile strength and puncture resistance.
Q: Does it self-seal fastener penetrations?
A: The self-sealing SBS rubber and asphalt blend is designed to self-seal and provide low air and vapor permeability.
Expert Verdict — Reviewed by the SuperArbor Pro Desk
Self-adhering vapor barriers are the cleanest way to meet low-permeance requirements under a commercial membrane, especially on projects where torch or hot-air welding of the barrier is impractical. Plan laps and substrate priming per the JM system detail, and stage the roof quickly since the 90-day exposure limit defines your schedule. The no-thermal-memory fiberglass mat makes it noticeably easier to lay flat in cool weather than stiff modified bitumen sheets.
Use caution on the nonslip surface when wet, follow safe roof-access practices, and consult the safety data sheet for handling of self-adhering bituminous materials.
Order the JM Vapor Barrier SAR roll for reliable self-adhering vapor protection on your next commercial roof.
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