Foundations: Connecting to the Earth

Shallow foundations transfer building loads to soil near the surface. The simplest is a spread footing—a widened concrete pad beneath a column or wall that distributes load over a larger area, reducing soil pressure. A continuous strip footing runs beneath bearing walls. When soil bearing capacity is low or loads are heavy, a mat (raft) foundation—a single thick concrete slab beneath the entire building—distributes the load most evenly. Shallow foundations are economical when competent soil (sand, gravel, or stiff clay) exists within 1-3 meters of the surface.