Diary of a Pool Project: Part 1 -- Busting Up the Backyard

With sturdy clay-like walls, the shape of the pool is easier to define. Looking at the positive side of digging into clay-like soil, the walls can be cut down to the desired depth and won't cave in, which could happen with fill or sandy soil. Picture building a sandcastle - unless you use sand mixed with water, caving occurs and you're back to square one.