The 3 things I learned when I had my foundation repaired that shocked me: clay heave can lift slabs, not just sink them
https://www.tumblr.com/ferociouslyradiantbastion/816235267421814784/foundation-repair-near-me-3-facts-to-check-before
The 3 things I learned when I had my foundation repaired that shocked me: clay heave can lift slabs, not just sink them, and root moisture removal can trigger upward movement.