Foam Backer Rod for Gaps Concrete Crack Filler Joints Foam Gap Fillers Caulk Saver Backing Rod Concrete Filler Rope Joint Filler (2 Inches X 6.6 Feet)

Foam Backer Rod for Gaps Concrete Crack Filler Joints Foam Gap Fillers Caulk Saver Backing Rod Concrete Filler Rope Joint Filler (2 Inches X 6.6 Feet)

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compubomb posted on r/homebuilding1w

https://a.co/d/0fqMksMD it'll fill the gap, and then silicon in the gaps.