concrete base thickness for a mortared flagstone patio
We live in the dallas metroplex area, where we have clay soil, and are planning on getting a patio built. The question is how much should the thickness of the concrete base be? We've been told by friends that it should be 4-6", however, the contractor says 3" should suffice. Also, he is not planning on putting any gravel. He will put the rebars at the bottom.
We are also planning on having a built-in grill and here we've been told again that atleast 12" is needed, but the contactor says 5" will do.
What is the thickness that is needed for under the grill and for the rest of the patio area. Please help!