Filling in settlement seam between steps and sidewalk

Old 07-05-16, 12:56 PM
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Filling in settlement seam between steps and sidewalk

A new sidewalk was laid about 10 years ago, up to the poured steps, which are on their own foundation. The sidewalk was laid on a packed gravel base with soil beneath. There is some wire in the concrete. The sidewalk began settling after a while. I used architectural caulk, but the sidewalk has now settled and the joint widened.

This gap is about an inch.

I'm looking for ideas about what to do. If there is a way to fill and caulk the gap, this is my first choice.

Other than this separation, the steps and sidewalk are in very good condition. But the seam is beginning to look bad and some water gets through there and down into the foundation area.

Behind the gap is a large hollow; you cannot just pack into the seam; it would require backing.

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Old 07-05-16, 02:15 PM
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It probably won't get better since the sidewalk is sinking. I would take a grinder with a wire wheel and extricate as much of the existing caulk as possible, leaving a clean surface on the sidewalk as well as the step riser. You may have to use 1/4" backer rod if the entire crack dictates it. If you don't raise the sidewalk hydraulically (first choice), then applying a flexible elastomeric sealant would be in order. Big Stretch is one. OSI Quad Max in a neutral color will work.
Old 07-05-16, 02:18 PM
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1 inch is pushing it for caulk, even something like big stretch. Since the joint will likely keep moving, you could insert a strip of concrete expansion joint strip and then caulk the now smaller gap. You will have to redo it every few years.

As an alternative, I've had good luck with this in a similar situation:

SlabGasket Expansion Joint Replacement (Gray)
Old 07-05-16, 02:28 PM
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I'd look into having the sidewalk mudjacked, as that big first step could turn into a liability issue.

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