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Johns Manville DynaWeld Base SBS Modified Bitumen Base and Ply Sheet, 39-3/8 in. x 32 ft 10 in. Roll
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Johns Manville DynaWeld Base SBS Modified Bitumen Base and Ply Sheet, 39-3/8 in. x 32 ft 10 in. Roll
JM DynaWeld Base is a fiber glass-reinforced SBS modified bitumen sheet used as a base or ply sheet in multi-ply roofing systems. Each roll measures 39-3/8 in. x 32 ft 10 in., in black. Its SBS rubber-asphalt blend gives the sheet the elasticity to handle roof expansion and contraction.
Key Features:
- Base or Ply Use: Used as a fiber glass-reinforced base or ply sheet in a variety of multi-ply roofing systems.
- Nonblocking Surface: Fine mineral parting agent creates a nonblocking surface suitable as a base sheet or ply sheet.
- SBS Flexibility: SBS rubber and asphalt blend lends elasticity and accommodates continual roof expansion and contraction.
- Dimensional Stability: Fiber glass reinforcement mat offers excellent dimensional stability and tensile strength.
- Easy Installation: No thermal memory means less time relaxing the sheet, speeding installation.
Specifications Table:
| Specification | Details |
|---|---|
| Brand | Johns Manville |
| Sell unit | 1 roll, 39-3/8 in. x 32 ft 10 in. |
| Product line | DynaWeld Base SBS |
| Available colors | Black |
| Available sizes | 39-3/8 in. x 32 ft 10 in. |
| Dimensions | 39-3/8 in. x 32 ft 10 in. roll |
| Material | SBS modified bitumen with fiber glass reinforcement mat |
| Finish / texture | Black, fine mineral parting agent surface |
| Intended use | Base or ply sheet in multi-ply BUR and modified bitumen roof systems |
Coverage & How Much You Need:
One 39-3/8 in. x 32 ft 10 in. roll covers roughly 108 sq ft at full width; actual coverage is less once laps and perimeter waste are accounted for. Plan laps per the system specification and add 10-15% for waste.
Fit and Compatibility:
Intended for multi-ply BUR and SBS modified bitumen assemblies, paired with appropriate membranes, adhesives or hot asphalt per the roof specification. Membranes, adhesives and flashing materials are sold separately.
Frequently Asked Questions (FAQ):
Q: What does one roll cover?
A: One roll measures 39-3/8 in. x 32 ft 10 in. (about 108 sq ft nominal); deduct laps and waste when estimating.
Q: Can it be used as a flashing sheet?
A: Yes, the product line is designated for use as a base, ply or flashing sheet in multi-ply systems.
Q: Why SBS modified bitumen?
A: The SBS rubber-asphalt blend gives elasticity and recovery so the sheet handles constant roof expansion and contraction.
Q: Is the surface self-sticking?
A: No, this is a base/ply sheet with a fine mineral parting agent; it must be installed with the system's specified adhesive, asphalt or torch application.
Q: Does the sheet hold its shape during install?
A: Yes, the fiber glass mat provides dimensional stability and has no thermal memory, so the sheet relaxes quickly.
Q: What color is the sheet?
A: Black.
Expert Verdict — Reviewed by the SuperArbor Pro Desk
DynaWeld Base is a dependable choice for base and ply courses in multi-ply assemblies where dimensional stability matters. Its lack of thermal memory lets the sheet lie flat quickly, which shortens installation time. Keep rolls protected from moisture before use and follow the specified lap and application method for the membrane system above.
Hot asphalt and torch application of modified bitumen carry fire and burn hazards; follow the specified application method and use proper protective equipment.
Order Johns Manville DynaWeld Base SBS sheet now for durable multi-ply roofing assemblies.
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