Our concrete contractor installed two garage aprons. He cut control joints that stopped 4 inches from our house, a block wall, and a wood retaining wall. Will we run into problems with cracking next to these structures because of this? At our instance he did install expansion joints between the concrete and these structures.

The pour was almost 2 weeks ago, so if cracking more than likely will occur, it it too late to finish the cuts ourselves?

1 Answer 1


His tool probably couldn't reach all the way to the house.

Your concrete is going to crack regardless of how many control joints there are. The control joints are analogous to electrical fuses, where stresses that would have induced unsightly cracks instead get relieved when the slab cracks at a control joint. In all likelihood there will eventually be a crack starting within the control joint and propagating erratically across the uncut concrete to the edge.

You can still cut the concrete. At 14 days you're probably at about 90% of the final compressive strength of the concrete (based on the scale where 100% is defined as the 28 day strength). You can still make the cuts. You too will have a problem getting all the way to the edge, but an angle grinder with a diamond cutting wheel will get you within an inch or two.

  • Appreciate your input! We will do this.
    – Pat
    Nov 6, 2023 at 2:08
  • Would you suggest doing wet or a dry cuts?
    – Pat
    Nov 6, 2023 at 2:57
  • @Pat, dust is the difference. Breathing concrete dust is very bad for you. As long as you're not a smoker, your body will naturally expel most of the dust. There's a narrow range of small particles, however, that your body has trouble expelling, 0.5 μm to 2 μm. N95 masks are at least 99% efficient with these particles (according to studies, not specifications), so use an N95 mask or HEPA filter mask if you cut it dry.
    – popham
    Nov 6, 2023 at 3:22
  • Personally, I'd do wet. Still worth using PPE.
    – Huesmann
    Nov 6, 2023 at 20:47

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