Slab sinking

[Missionstreet]

I have a relatively new concrete slab that is about 23 by 13'. It is built on a bit of a grade with coordinated drainage pipe underneath.

It really is two pieces, 12x13 each. I noticed the side closer to the slope sunk about 1/4" to *gasp* 1/2" near the center where they meet after backing up into it and then changing direction again. (There is a perpenducular crack in the center to so it isn't sinking evenly)

Any thoughts?

[Missionstreet]

This is existing from a previous owner

[Missionstreet]

Humm I wonder how much it'll sink

[dedmiston]

Was the pad professionally graded and compacted?

[98coachman]

You can compact the ground until you are blue in the face and you won't reach 100 % compaction. The ground will still settle! The slabs should have been pinned together to eliminate uneven heights or seperation. Good luck, it will probably keep moving.

[time2roll]

I would assume the base was not properly prepared. What does the concrete contractor say?

[MDKMDK]

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