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Johns Manville DynaBase SBS Modified Bitumen Base or Ply Sheet, Fiber Glass-Reinforced, 39-3/8 in. x 49 ft 2 in. Roll, Black
Regular price $84.50Orders start at $399 — combine any items to reach the minimum. Learn more
Johns Manville DynaBase SBS Modified Bitumen Base or Ply Sheet, Fiber Glass-Reinforced, 39-3/8 in. x 49 ft 2 in. Roll, Black
JM DynaBase is a fiber glass-reinforced SBS modified bitumen sheet used as a base or ply sheet in multi-ply roofing systems. Each black roll measures 39-3/8 in. x 49 ft 2 in. and features a high-quality SBS rubber-and-asphalt blend for elasticity and recovery. A fine mineral parting agent on both sides makes handling and installation easier.
Key Features:
- Base or Ply Use: Functions as a fiber glass-reinforced base or ply sheet in a variety of multi-ply roofing systems.
- SBS Flexibility: The SBS rubber and asphalt blend lends elasticity and flexibility to the sheet.
- Elongation & Recovery: Elongation and recovery properties accommodate continual roof expansion and contraction.
- Fiber Glass Mat: The fiber glass reinforcement offers excellent dimensional stability and tensile strength.
- No Thermal Memory: With no thermal memory, the sheet relaxes faster for easier installation.
- Parting Agent: A fine mineral parting agent on both sides of the sheet aids handling.
- Withstands Movement: The fiber glass mat withstands differential movement in the roof assembly.
Specifications Table:
| Specification | Details |
|---|---|
| Brand | Johns Manville |
| Sell unit | 1 roll, 39-3/8 in. x 49 ft 2 in. |
| Product line | JM DynaBase |
| Available colors | Black |
| Available sizes | 39-3/8 in. x 49 ft 2 in. roll |
| Material | SBS rubber and asphalt blend with fiber glass reinforcement mat |
| Dimensions | 39-3/8 in. wide x 49 ft 2 in. long |
| Finish / texture | Fine mineral parting agent on both sides |
| Intended use | Base or ply sheet in multi-ply (BUR and modified bitumen) roofing systems |
Coverage & How Much You Need:
One roll is 39-3/8 in. x 49 ft 2 in., covering roughly 160 sq ft at full width; plan laps per system specification, which reduces effective coverage.
Fit and Compatibility:
Used as a base or ply sheet within multi-ply roofing systems, including JM BUR and modified bitumen assemblies. System adhesives, moppings and cap sheets are sold separately.
Frequently Asked Questions (FAQ):
Q: What is DynaBase used for?
A: It is used as a fiber glass-reinforced base or ply sheet in a variety of multi-ply roofing systems.
Q: What are the roll dimensions?
A: Each roll measures 39-3/8 in. x 49 ft 2 in. in black.
Q: What reinforcement does it use?
A: A fiber glass mat that provides dimensional stability and tensile strength.
Q: Why does the SBS blend matter?
A: The SBS rubber-and-asphalt blend gives the sheet elasticity and recovery to handle roof expansion and contraction.
Q: Is it easy to install?
A: Yes, the sheet has no thermal memory, so it relaxes faster and installs with less effort.
Q: How is the sheet surfaced?
A: A fine mineral parting agent covers both sides of the sheet.
Expert Verdict — Reviewed by the SuperArbor Pro Desk
DynaBase is a dependable base/ply choice where differential movement or thermal cycling is a concern, since the fiber glass mat holds dimensions while the SBS blend flexes. Allow the roll to relax and reach ambient temperature before unrolling to keep the sheet flat. Follow specified side and end laps, and embed fully in the system's bitumen or adhesive.
Hot-applied bitumen and torch methods carry fire and burn risks; follow the roofing system's specified installation method and required safety practices.
Order JM DynaBase SBS base or ply sheet by the roll for your next multi-ply roofing job.
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