Foundation Stabilization System and Method of Use

Abstract

A system for stabilizing moisture content of soil adjacent a building foundation uses a French drain which is dug around a perimeter of the building and grey water produced in the building as a source of irrigating fluid. Grey water sources from within the building are directed to the French drain through conduits which are separate from the normal sewage lines leading to the sanitary sewer system. An overflow conduit diverts any excess overflow from the French drain to the sanitary sewer line.

I claim: 
     
         1 . A method for stabilizing moisture content of soil around and beneath the foundation of a building where the foundation is surrounded by a soil perimeter, the building also having a plurality of sources of grey water produced in the building and a sanitary sewer conduit which receives sewage from the building, the method comprising the steps of:
 constructing a French drain in the soil around the complete outside perimeter of the foundation, the French drain including a perforated conduit which is buried in a surrounding particulate drainage material, the particulate drainage material being contained in a trench dug around the perimeter of the building foundation, the perforated conduit being pervious to water, allowing water from the perforated conduit to pass through the particulate drainage material and to enter the surrounding soil;   directing grey water produced within the building through a plurality of grey water conduits to the perforated conduit of the French drain, whereby grey water is directed outwardly from the French drain into the soil surrounding the foundation of the building; and   directing any sewer water produced in the building through separate fluid conduits to the sanitary sewer conduit.   
     
     
         2 . The method of  claim 1 , wherein the building is a residential dwelling structure. 
     
     
         3 . The method of  claim 1 , wherein the building foundation is situated on a surrounding strata comprised at least in part of expansive clay. 
     
     
         4 . The method of  claim 1 , wherein the source of the grey water is selected from among the group consisting of water from a laundry sink, water from a clothes washer, water from a lavatory, water from a tub and water from a shower in the building. 
     
     
         5 . The method of  claim 1 , wherein the perforated conduit is connected to the sanitary sewer conduit at at least one point by an overflow conduit, the overflow conduit having a check valve contained therein which accepts an excess of grey water produced in the building structure, but which prevents sewage in the sanitary sewer from reentering the grey water conduit or perforate conduit through the check valve. 
     
     
         6 . The method of  claim 1 , wherein the check valve is a rubber duck bill valve which opens in response to the flow of grey water only. 
     
     
         7 . The method of  claim 1 , wherein the particulate perforate material is selected from the group consisting of sand, gravel and rock. 
     
     
         8 . The method of  claim 1 , wherein the particulate perforate material which is contained in the trench which is dug around the perimeter of the building foundation is enveloped in a fabric material which helps to prevent the infiltration of soil into the perforate material but which allows the egress of water from the particulate material into the surrounding soil. 
     
     
         9 . The method of  claim 8 , wherein the building has a building roof which directs rainfall water downwardly, and wherein a deflector sheet of a predetermined width extends outwardly from the building foundation over the French drain and into the surrounding soil, whereby rain water which runs off the building roof is directed away from the French drain and outwardly toward the surrounding soil to prevent flooding of the French drain. 
     
     
         10 . The method of  claim 9 , wherein the deflector sheet is a sheet of roll plastic.