For more than 10 years, I have been trying to renovate my house, but cracks in the walls keep appearing, and no matter how many times I fix the doors, they will not shut! The problem was that ¾ of the house had a sand foundation and ¼ was on clay. The pylons were only put in the ground about 6 inches, and there is a spring besides the house! For 10 years, I have tried to fix it from the top down. I failed, and it has cost me tens of thousands of dollars. I realised that there was no way around it; I had to dig out the foundations and do it from the ground up.