Illustration: example soil layers, a borehole with sampling points and a foundation designed from the results. Not to scale; actual soil varies from plot to plot. The foundation is the one part of your house you will never see again once it is built, and it is the hardest part to fix later. Before you spend on bricks, steel and finishes, it pays to know what lies under your plot. That is what a soil test tells you. This guide explains soil testing before construction in Gorak