re: Replacing wood expansion joints in concrete driveway

quote:

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using backer rod and a self leveling sealant

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In my experience, when wood was used in a joint originally, the joint started at 3/4" (1" piece of wood) and expands to 7/8" to 1 1/4" over the years by the time the wood rots. The backing rods from the likes of Sika are sold as 3/4" wide (round) and the correct procedure for putting 3/4" backing rod in larger joint is to twist them together. It's foam, but after twisting two 3/4" together, the joint really needs to be 1 1/2". The typical 7/8" to 1 1/4" gaps I see are no-mans land for backing rods. I've even tried heating with torch to reduce the foam, but just doesn't work. Things have to be really neat and tight for self leveling.

So I'm following this as well for varying width joints/gaps in old concrete.