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horizontal crack in block below front porch

horizontal crack in block below front porch

horizontal crack in block below front porch

(OP)
Please view the attached photo file and comment on the cause of the horizontal cracking between the top two courses of CMU block.

what caused the horizontal crack between the top two courses of block? The block is below a front porch concrete slab. The porch is approximately 8'x25'. I opine that the horizontal crack is due to a combination of foundation settlement and frost heave (very cold winter region, cracks noticed after winter months). Relatively flat ground slopes surrounding porch. root cellar of an unknown size below. thank you.

RE: horizontal crack in block below front porch

How deep does the CMU extend below grade? That should give a hint if it is frost related.

To me it looks like settlement of the CMU block, was there any compaction effort before the blocks went in?

Check where the pad is bearing on the block, there might be a few high points - which will cause cracking eventually (acting like a suspended slab when it shouldn't). Once you rule out frost heave re-grout to give full bearing.

If frost is the issue... well you can either live with it, or best bet would be to delta warp the block below grade and tie into your drainage tile to de-water the soil. No liquid = no heave.

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