In the twenty some odd years of working in construction, with and for my father, I heard him asked by at least two dozen different customers
” How do you fix a bad foundation?”
They usually would enumerate the various methods ” foundation repair ” companies advertised;
mud jacking, I-beams driven down to bedrock, wrapping tension cables around the house , etc.
He always gave the same answer; “Rip it up and pour a new one”.
They would invariably try to find some way around this unwelcome news by touting the imagined suitability of one method or another to their particular situation.
Dad would get a tired look on his face and, in a voice suitable for explaining to a child that you can’t breathe underwater , he would say;
“If you have foundation problems it isn’t because of the soil or the heat or the humidity, it’s because the foundation was laid wrong or badly.
The way you fix something that was done wrong is to do it right. Rip it up and pour a new one”
I heard him answer this question at least two dozen times, I never heard anyone thank him for the information.