R25B Tape — Heavy-Duty Liner Seaming Tape for Polyethylene & Polypropylene
R25B Tape is an 8 mil single-sided liner seaming tape built for instant, aggressive bonding to PE and PP surfaces — without heat welding.
First, you prep the surface. Then you align the tape, peel the liner, and roll it down. That’s it — no torches, no welders, no extended cure time. Whether you’re seaming a geomembrane, patching a vapor barrier, or sealing around penetrations, R25B delivers immediate tack and long-term UV stability so your seams hold up under direct sunlight and temperature swings.
💡 Built for field repairs and exposed seams. Above all, R25B is the liner seaming tape contractors reach for when welding equipment isn’t available or a fast, surface-applied repair is required.
Features and Benefits
Aggressive Synthetic Elastomeric Adhesive
R25B uses a high-tack 17 mil synthetic elastomeric adhesive that bonds instantly to properly prepared polyethylene and polypropylene. As soon as you apply pressure, the adhesive wets out and forms a durable bond that resists peel-back and edge lifting — even on textured liner surfaces. Furthermore, with an adhesion value of 144 oz/in to steel, R25B ranks among the most aggressive seam tapes available for poly substrates.
UV-Stable Black Polymer Backing
The 8 mil black polymer backing stands up to outdoor exposure. Specifically, it resists UV degradation, weathering, and dimensional change across temperature swings. As a result, R25B works well for exposed geomembranes, containment liners, and above-grade vapor barrier seams.
Low-Profile, Conformable Construction
At 8 mil total thickness, R25B lays flat against the substrate without bulk build-up. In addition, it conforms to irregular surfaces, pipe penetrations, and patch edges, leaving a clean finish that won’t catch or lift under foot traffic or wind load.
Easy Field Installation
The poly release liner peels away cleanly so you can align the tape, position it precisely, and then activate the bond with hand-roller pressure. No heat. No specialized equipment. No extended cure time.
Vapor-Tight Seal
With a permeance rating of less than 0.005 g/(24h·100 in²), R25B creates a near-impermeable seal. Consequently, it works for vapor barrier seaming, crawl space liner repair, and sub-slab containment — anywhere moisture control is critical.
🌱 Ideal for: geomembrane installers, environmental remediation contractors, vapor barrier installers, and crawl space encapsulation pros.
Why Liner Seaming Tape Matters
A liner system is only as reliable as its seams. In other words, the seam is where most failures start — whether you’re protecting groundwater under a containment pad, sealing a vapor barrier in a crawl space, or patching a tear in an exposed pond liner. However, heat welding isn’t always practical. Equipment access, weather, surface conditions, and labor cost all push contractors toward a tape-based solution. Therefore, the right liner seaming tape closes that gap with a fast, mechanical bond that performs in real-world jobsite conditions.
We engineered R25B specifically for this scenario. First, it’s aggressive enough to bond on first contact. Second, it’s durable enough to stay sealed for years. Finally, it’s thin enough to lay flat under continued use.
| Feature | Benefit |
|---|---|
| Aggressive Synthetic Elastomeric Adhesive | Bonds instantly to PE and PP without heat welding, cutting installation time on the jobsite. |
| UV-Resistant Black Polymer Backing | Holds up under direct sunlight and weather exposure, extending the service life of exposed seams. |
| 8 Mil Low-Profile Construction | Conforms to substrate surfaces and lays flat, leaving a clean finish on patches and seams. |
| Permeance < 0.005 g/(24h·100 in²) | Creates a vapor-tight seal suitable for moisture-critical containment and vapor barrier work. |
| Service Range +20°F to +180°F | Performs across seasonal temperature swings on exposed and below-grade applications. |
| Poly Release Liner | Allows precise tape placement before bond activation, reducing waste from misaligned seams. |
💰 Save time, skip the welder. Ultimately, one 4″ × 100′ roll of R25B replaces hours of heat-weld setup on small repairs and detail work — and it travels with the rest of your hand tools.
Common Applications
- Geomembrane seam overlay and reinforcement
- Polyethylene and polypropylene liner repair
- Vapor barrier seaming in crawl spaces and sub-slab applications
- Sealing around pipe penetrations and pipe boots
- Edge sealing on exposed liner systems
- Patch reinforcement on torn or damaged liners
- Temporary containment sealing during remediation work
- Surface detailing on UV-exposed pond and containment liners
🌑 Need a liner to seam? For containment and geomembrane projects, pair R25B Tape with our heavy-duty liners. In addition, for crawl space and sub-slab moisture control, use it with our vapor retarders.
Frequently Asked Questions
What surfaces does R25B Tape bond to?
R25B bonds aggressively to polyethylene (PE) and polypropylene (PP) surfaces. However, it is not recommended for porous substrates, oily surfaces, or materials outside the PE/PP family without testing.
How do I install R25B Tape?
First, clean the substrate thoroughly to remove dust, moisture, and contaminants. Next, confirm the surface is fully dry. Then align the tape on the seam or patch area before removing the release liner. After that, peel back the poly release liner and apply firm, uniform pressure. Finally, use a hand roller to maximize adhesive contact across the full bond area. Minimum application temperature is 35°F.
💡 Pro tip: Above all, surface prep matters. A hand roller — not finger pressure — activates the full bond strength. Skip the roller and you’ll see edge lift within weeks.
Can R25B Tape be used in direct sunlight?
Yes. The black polymer backing is UV-stable and specifically formulated for outdoor exposure. As a result, R25B works well for exposed geomembranes, pond liners, and above-grade containment seams. Outdoor lifespan depends on weather, fastening method, and site conditions.
What is the service temperature range for R25B Tape?
R25B has a service temperature range of +20°F to +180°F once installed. However, minimum application temperature is 35°F — installing below that threshold can compromise initial tack and final bond strength.
Is R25B Tape vapor-tight?
Yes. R25B has a permeance rating of less than 0.005 g/(24h·100 in²). Therefore, it qualifies for vapor barrier seaming and moisture-critical containment work where a near-impermeable seal is required.
What size does R25B Tape come in?
R25B comes in a 4″ × 100′ roll. For project-specific quantities or custom requirements, contact our team at 800-747-6095 or sales@americover.com.
How should R25B Tape be stored?
Ideal storage conditions are 70°F with 40–50% relative humidity. In addition, keep rolls in original packaging, away from direct sunlight and extreme temperatures, until ready for use.
