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(06-11-2024, 11:33 AM)grwold Wrote: I picked up some Sika poly sealant & backer for the concrete driveway's expansion seams, and am going to give that a try.
What to use, though, for the cracks in the brick walk? Those cracks go from very thin, maybe 1/32" & up ...
... to up to 1/4" ...
I'd like to slow the cracking & expansion as best I can.
Angle grinder with masonry wheel. Grind it out and tuckpoint is the only way I know that or after grinding it out place the Sika in the shallow place you ground out. If there is a lot of ground movement under the sidewalk it may not work. It looks like it might be a freeze thaw issue where water gets in crack and freezes thus expanding the crack each time. Roly
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(06-11-2024, 11:52 AM)Roly Wrote: Angle grinder with masonry wheel. Grind it out and tuckpoint is the only way I know that or after grinding it out place the Sika in the shallow place you ground out. If there is a lot of ground movement under the sidewalk it may not work. It looks like it might be a freeze thaw issue where water gets in crack and freezes thus expanding the crack each time. Roly
I had to look up "tuckpoint". So that'll fix, at least temporarily, the cracks running through the mortar. I suppose Sika could be forced into the larger cracks that cross the bricks (or, those bricks could be replaced).
I'm pretty sure you're right about freezing/thawing being the major cause. There is some settling going on, too.
Thanks for the response, both Roly and Snipe.
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06-15-2024, 06:30 AM
(This post was last modified: 06-15-2024, 06:32 AM by Snipe Hunter.)
After thinking about it, I might just sweep in polymeric sand and live with the cracks. Sweep in some more as cracks re-appear. Your walkway is likely cracked due to settling but the bricks are cracked too so there's a lot of pressure coming from somewhere. Or the bricks are mortared to a concrete slab and the cracking slab is causing the bricks to crack. Or It probably wasn't installed over a good, packed gravel base but if it was on gravel, the installer probably wouldn't use mortar between the bricks. . Freezing may be causing the expansion in the cracks and or the slab beneath it. .. assuming it freezes where you are. In a nutshell, it will probably continue to happen. Whatever is causing it didn't go away.
A proper repair would be to replace it on a proper bed like concrete. Or on good, compacted gravel bed and use a polymeric sand instead of mortar. That way, you just sweep in more sand when joints expand. And you won't have to deal with the energy causing the bricks to crack, the energy gets dampened in the polymeric sand.
I think you'll be chasing your tail until it's replaced.
Death, taxes and concrete cracks
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Thanks for the update, Snipe.