Foundations/footings in mixed rock/clay Drainage pipes, concrete, footings and foundations. Post your questions and find answers here

[Miradlyn]

I am about to build a garden wall and a garage where the footings will be in part rock and part clay. How do I overcome the problem of where the two meet where the clay might move in time but the rock will not move. do I ned to put some form of reinforcement in with the footings and if so how much and where.