In this invention, after the grade at a construction site has been excavated and/or graded to its preliminary rough grade, re-enforcing material, typically synthetic in nature, such as nylon or polypropylene mesh or rods, fiber-glass rods or mesh, or other specified re-enforcing material is laid across soil at the construction site and a reinforced base is formed by covering the reinforcing material with a polymeric resin, whereby upon curing, the polymeric resin and reinforcing material forms a contiguous thermo-structural base. Re-enforcement material comprising synthetic and/or non-synthetic components in the form of rods, rope, strapping, mesh, netting, geotextile fabrics or other dimensional forms laid longitudinally, or in a grid pattern, in single or multiple layers, tied or not tied all in situ sprayed with a high density closed cell, water resistant expanding two component polyurethane foam system. The reinforcing material may be nylon, polypropylene, fiberglass, other synthetic or non-synthetic materials or combinations of these materials.