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Open Cell Backing Rod - RoundVendor:
For sealing expansion joints, precast panels, window glazing, and bridge construction, Open Cell Backing Rod - Round acts as a critical bond breaker to prevent three-sided sealant adhesion. Its open-cell structure accelerates sealant curing by allowing the joint to breathe and cure from both...- From $138.36
- From $138.36
- Unit price
- per
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Open Cell Backing Rod - SquareVendor:
Square-section open-cell backing rod for square and rectangular joints. It sits in the base of the joint to set the sealant depth and stop three-sided adhesion, which is what cracks beads.Open cell structure lets gas out, so the sealant cures without bubbling from the...
- From $3.06
- From $3.06
- Unit price
- per
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Adheseal Backing Rod Closed Cell - RoundVendor:
For expansion joints, window glazing, precast panels, and bridge construction where three-sided sealant adhesion must be prevented, Adheseal Backing Rod Closed Cell - Round provides the essential depth control and bond-breaking foundation. This flexible, low-density white polyethylene foam rod establishes the correct joint profile...
- From $12.30
- From $12.30
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- per
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Biyseal Bitumen Impregnated FoamVendor:
For sealing metal cladding, expansion joints, roof valleys, and building penetrations against weather, dust, and vermin, Biyseal Bitumen Impregnated Foam provides a compressible, pre-formed barrier that expands and contracts without losing its recovery properties. Impregnated with bitumen, this flexible polyurethane strip exerts continuous outward...
- From $134.19
- From $134.19
- Unit price
- per
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Biyseal Acrylic Impregnated FoamVendor:
For sealing expansion joints, roof cladding, and window or door perimeters against weather, Biyseal Acrylic Impregnated Foam provides a highly compressible barrier that adapts to continuous joint movement. This high-density polyurethane foam is impregnated with an acrylic solution, allowing it to expand and contract...
- $136.58
- $136.58
- Unit price
- per
Frequently Asked Questions
Why use backing rod in a sealant joint?
Backing rod controls the sealant depth and helps create the correct hourglass joint profile. It also prevents three-sided adhesion, allowing the sealant to move as designed. Select the rod size and material for the joint width, depth, exposure and specified sealant system.
Which backing rod type should I choose?
Open-cell, closed-cell and fire-rated backing rods serve different joint requirements. Closed-cell foam limits moisture entry, open-cell foam may suit particular joint designs, and fire-rated products are used only where the tested system requires them.
How tightly should backing rod fit?
The rod should fit securely without being stretched, cut or compressed beyond the manufacturer’s guidance. Oversizing can damage the joint faces or distort the sealant depth; undersizing can allow movement or loss of support. Use an insertion tool where needed to place the rod consistently.
Can I puncture closed-cell backing rod?
Avoid damaging closed-cell rod during installation because punctures can allow moisture into the material and change its performance. Use a blunt insertion method and do not use sharp tools that cut the foam. Replace damaged sections before applying the sealant.
Is backing rod required for every joint?
No. It is used where joint geometry and the sealant system require controlled depth or bond-breaker support. Some shallow gaps or specific proprietary systems use another detail. Check the joint design, sealant technical data and project specification before deciding how to prepare the joint.