I have an one inch gap in my concrete. Is the one inch wide backer rod sufficient to fill in the gap?

Hello, and thank you for your question. A 1-inch diameter backer rod is designed for gaps that are approximately 1 inch wide or slightly smaller. For best results, the backer rod should fit snugly into the joint without being forced—typically compressed about 25–50% of its diameter. If your concrete gap is exactly 1 inch or slightly under, the 1-inch backer rod should work well. However, if the gap is larger than 1 inch, you may need to move up to the next size to ensure a proper seal and support for the joint sealant. Thank you, M-D Team