The 3 things I learned when I had my foundation repaired that shocked me were the difference between helical

https://www.scribd.com/document/1037418377/Top-3-Things-to-Know-Before-Calling-a-Foundation-Repair-Company-for-Basement-Waterproofing-179026

The 3 things I learned when I had my foundation repaired that shocked me were the difference between helical and push piers, when each is used, and why depth beats count.