Caulk Backer Rod 1/2" x 20'

Enhance the performance and longevity of your caulking projects with this 1/2" x 20' closed-cell backer rod. Designed to fill larger gaps before caulking, it prevents three-point bonding and ensures a clean, consistent seal. Ideal for expansion joints, pavement cracks, wall joints, and foundations, this polyethylene rod insulates, cushions, and provides a solid backing for a professional finish.

Whether you're working on driveways, sidewalks, or exterior walls, this backer rod simplifies application and reduces caulk usage by acting as a gap filler. Its water-resistant, non-absorbent material stands up to moisture while maintaining flexibility and durability.

Key Features

• Acts as a filler in gaps and openings larger than 1/2" to prevent drafts and three-point bonding
• Closed-cell polyethylene construction for non-absorbent performance
• Provides a stable, sound surface for caulk and sealant
• Cushions movement in expansion joints to reduce cracks
• Suitable for use in driveways, sidewalks, walls, foundations, and other large joints

⚠️ WARNING: This product can expose you to Carbon-black extracts known to the State of California to cause cancer. For more information, visit www.P65Warnings.ca.gov.