Underground drainage sump system and method of retrofitting for

Abstract

A method of retrofitting an underground water drainage sump system to below a floor slab for protecting the floor slab includes the steps of forming a sump hole below a floor slab of a building, drilling into and removing soil from below the floor slab so as to form a plurality of lateral passageways extending from a central location relative to an outer perimeter of the floor slab, extending the lateral passageways outwardly at two different levels and lengths and alternating therebetween to and beyond a footer at the outer perimeter of the floor slab, inserting a plurality of perforated collection pipes into the lateral passageways, placing a perforated drum into the sump hole such that inner ends of the perforated collection pipes are adjacent to the perforated drum, filling the sump hole around at least the lower portion of the perforated drum with drainage stones, placing a sump pump into the perforated drum, connecting the sump pump to a discharge pipe for transporting the drainage water from the perforated drum into a sewer system of the building or otherwise to the outside of the building away from the floor slab, and providing a cover for removably covering the sump hole.