Alcot Plastics Ltd. is one of Canada’s most trusted manufacturers of high-quality polyethylene foam backer rods — including both standard closed-cell and flexible soft backer rods for specialized applications. Since 1983, we’ve served industries across construction, infrastructure, and glazing with durable, non-absorbent foam products engineered for performance and consistency.
Our backer rods are available in a wide range of diameters. Standard closed-cell backer rod is offered in ¼” to 1 ¼” rolls and larger sizes (up to 4″) in six-foot carton lengths. For joints that vary in size or require extra compressibility, our Soft Backer Rod is the ideal alternative — designed specifically for irregular joints and situations where bubbling or gas entrapment is a concern.
Why Use Backer Rods?
Backer rods help create optimal joint conditions for cold-applied sealants. Whether you’re sealing concrete, wood, glass, or metal, our rods act as a bond breaker, control joint depth, and reduce the amount of sealant needed — saving time and material cost.
Key Benefits
- Improved joint design – Ensures the sealant forms the correct profile for flexibility and performance
- Minimizes three-sided adhesion – Reduces sealant stress, improving service life
- Air and moisture barrier – Closed-cell structure resists water and air infiltration
- Reduces sealant waste – Fills space efficiently, reducing excess product use
- No bond breaker required – Especially with Soft Backer Rod, sealants don’t adhere
Standard vs. Soft Backer Rods: What’s the Difference?
| Feature | Closed-Cell Backer Rod | Soft Backer Rod |
|---|---|---|
| Cell Structure | Closed-cell | Bi-cellular (extra compressible) |
| Recommended Use | Uniform joints with consistent depth | Irregular or variable-width joints |
| Gas/Bubble Resistance | May trap gas in some cases | Non-gassing, no bubbling |
| Applications | General construction, glazing, sealing | Log homes, bridge joints, retrofits |
| Bond Breaker Needed? | No (compatible with most sealants) | No (sealants don’t adhere) |
Applications
Construction and Glazing
Ideal for expansion joints, windows, doors, and precast concrete, backer rods support sealant performance in vertical and horizontal applications.
Civil and Infrastructure Projects
Used on bridges, highways, and runways — backer rods withstand movement, temperature swings, and weather exposure.
Log Cabins and Timber Structures
Soft rods provide excellent movement accommodation for natural wood shrinkage and expansion, preventing drafts and moisture intrusion.
Marine and Deck Installations
Non-absorbent polyethylene foam resists moisture, making it useful for boat hatches, decks, and non-submerged sealing.
Solar Panel Installations
Soft backer rods seal around rooftop-mounted panels, blocking out water and air for long-term protection.
Why Choose Alcot Plastics?
Precision and Performance
Our backer rods are made with durable polyethylene foam that resists compression set, breakage, and chemical exposure.
Full Range of Sizes and Densities
From narrow joints to deep fills, we offer the most commonly used diameters — and can produce custom sizes to suit your project.
Quick Turnaround, Low Waste
Thanks to our efficient extrusion technology, we handle both large orders and short production runs with minimal material waste and fast delivery. Contact us to request a quote today.
Product Downloads
📄 Download Standard Backer Rod PDF
📄 Download Soft Backer Rod PDF
Ready to Order?
Need help deciding between standard or soft backer rod? Contact Alcot Plastics today and talk to our experts.
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