U.S. patent application number 13/236872 was filed with the patent office on 2013-03-21 for foundation stabilization system and method of use.
The applicant listed for this patent is Rod Ekern. Invention is credited to Rod Ekern.
Application Number | 20130071186 13/236872 |
Document ID | / |
Family ID | 47880800 |
Filed Date | 2013-03-21 |
United States Patent
Application |
20130071186 |
Kind Code |
A1 |
Ekern; Rod |
March 21, 2013 |
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.
Inventors: |
Ekern; Rod; (Arlington,
TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Ekern; Rod |
Arlington |
TX |
US |
|
|
Family ID: |
47880800 |
Appl. No.: |
13/236872 |
Filed: |
September 20, 2011 |
Current U.S.
Class: |
405/45 ;
405/50 |
Current CPC
Class: |
E02B 11/00 20130101 |
Class at
Publication: |
405/45 ;
405/50 |
International
Class: |
E02B 13/00 20060101
E02B013/00; E02B 11/00 20060101 E02B011/00 |
Claims
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.
Description
BACKGROUND OF THE INVENTION
[0001] A. Field of the Invention
[0002] The present invention relates generally to a method for
controlling and stabilizing the moisture content of soil around and
beneath the foundation of a building, such as a residential
building structure, particularly where the structure is located on
expansive soils.
[0003] B. Description of the Prior Art
[0004] As is well known in the civil engineering arts, foundation
soils expand and contract to a greater or lesser degree according
to the moisture content of the soils. While soil shrinkage and
expansion can be a problem in any geographical area, those area
having a high clay content are especially vulnerable. Certain types
of soil, such as the clay soils of parts of the South, Southwest
and Mid-western regions, for example, can expand many orders of
magnitude with the addition of sufficient moisture content. These
clays may have a high montmorillinite content which causes the
soils to have the extreme expansive characteristics. In the South
and Southwest, the so-called "black gumbo" soils continually expand
and contract, depending upon the moisture content of the soils.
[0005] One can readily see that buildings may be damaged by such
expansion and contraction of the soils surrounding and beneath the
foundation. Damage of this type to foundations results in large
expenditures on the part of homeowners each year. Repeated wetting
and drying of the soil, particularly when done unevenly, can place
great stress on the foundations resulting in tilting, cracking and
even ultimate destruction of the foundation. This, of course, often
results in damage to structures supported on such foundations.
[0006] It is believed that many instances of building foundation
stress in these situations is a result of migration of moisture
from beneath the perimeter of the beams of the foundation, with
resulting shrinkage of the soils and a loss of soil support at the
perimeter of the foundation. This shrinkage occurs after extended
periods of dry weather, such as that which is common to the summer
months in the South, Southwest and Midwest regions of the United
States. The loss of moisture from the soil surrounding the
foundation causes moisture in the protected area under the
foundation to migrate into the depleted surrounding soil. This
reduction of moisture content of the soil under the edges of the
foundation causes the soil to contract and move away from the
foundation. At the very least, the soil beneath the foundation goes
up and down in overall volume, thereby causing the foundation,
masonry and interior sheetrock to be ruptured or cracked. In more
serious cases, door structures and window structures may be cracked
and serious distresses may be induced into the structure of the
building itself.
[0007] When the normal fall and winter rains replenish the soil
moisture, the cycle is reversed. Moisture then migrates back under
the foundation perimeter, swelling the supporting clays and moving
the perimeter beams in a vertically upward direction. The perimeter
of the foundation will continue to move up and down with the
seasonal cycle with the magnitude of movement varying with the
extremes of the wet-dry weather cycles.
[0008] To solve these problems, a variety of remediation and repair
techniques have been used and the results vary widely. One
technique is to utilize a massive slab and beam structure, or a
series of concrete "piers", which will not fail as the soil shrinks
and expands. Although, in some instances, these techniques may be
successfully utilized, they are undesirable in that they are often
times inordinately expensive and increase the construction costs in
these structures. In addition, this technique cannot be used on
existing foundations.
[0009] A second technique is to attempt to repair the damage to the
existing foundations by grouting the cracks formed in the
foundation due to the shrinking and swelling of the soil. These
attempts may actually act to increase the damage to the foundation
when the cycle is reversed in that the foundation cannot return to
its original position because of grout material in the crack.
[0010] Other techniques have included attempts to stabilize the
expansive soil present under a foundation. Stabilization techniques
utilize lime slurry material which is injected into the soil under
high pressure. The effectiveness of the use of this lime material
is variable and believed to be a result of a chemical reaction that
takes place between lime and clay whereby some types of clay
particles are significantly altered and reduced in plasticity and
increased in mechanical strength. It was believed that this
chemical reaction could be achieved throughout the soil by mixing
lime with the soil under the foundation. However, it has been found
that such mixing is very limited. The process can be quite
expensive and the results are not always predictable.
[0011] Another technique was the use of a surface or subsurface
irrigation system positioned around the foundation to control the
moisture content of the soil under the foundation. These early
systems were nothing more than simple soaker hose, drip irrigation
systems laid on top of the ground surrounding the foundation and
controlled by an individual on an as-needed/as-remembered basis.
More elaborate systems were also devised in which permeable hoses
or pipe similar to the type used in lawn irrigation systems are
placed in the soil of the foundation. A low head pressure of water
was then connected to the pipes causing water to slowly percolate
into the soil supporting the foundation. The irrigation system can
be placed adjacent to the edge of the foundation and moisture
sensors imbedded around the house to control the operation of the
system. These types of systems may be relatively successful in
attacking the problem of uneven moisture in the surrounding soils,
but they have the disadvantage of using water from the City main or
other pressurized water source in order to make the systems
function. This can result in the use of a fairly large amount of
City water each year and adds to the problem of an ever decreasing
water table level in many parts of the country.
[0012] Thus, prior art systems for stabilizing moisture content of
soil around and beneath the foundation of a building leave much to
be desired. Although they may operate with limited success, the
prior art systems are not uniformly effective and efficient.
Perhaps equally important, many of the prior art systems used water
from the City water system, or from the homeowner's private well,
as the source of irrigation water for the system. This was costly
and environmentally unfriendly in many respects. Substantial
improvements are thus need in the area of foundation stabilization
systems.
SUMMARY OF THE INVENTION
[0013] A method is shown for stabilizing the 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. A French drain is dug in the soil around the complete
outside perimeter of the foundation. The French drain includes a
perforated conduit which is buried in a surrounding particulate
drainage material. The particulate drainage material is contained
in a trench dug around the perimeter of the building foundation.
The perforated conduit is pervious to water, allowing water from
the perforated conduit to pass through the particulate drainage
material and to enter the surrounding soil.
[0014] Grey water produced within the building is directed 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. Any sewer water which is produced within the building is
directed through separate fluid conduits to the sanitary sewer
conduit.
[0015] In the typical case, the building is a residential dwelling
structure where the building foundation is situated on a
surrounding strata comprised at least in part of expansive clay.
The source of the grey water can be, for example, 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.
[0016] The perforated conduit is connected to the sanitary sewer
conduit at at least one point by an overflow conduit. The overflow
conduit has 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. The
check valve can be, for example, a rubber duck bill valve which
opens in response to the flow of grey water only.
[0017] The particulate perforate material can be selected from
among the group consisting of sand, gravel and rock. The
particulate perforate material, 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.
[0018] A sheet of plastic material forms a deflector sheet of a
predetermined width which extends outwardly from the building
foundation over the French drain and into the surrounding soil. As
a result, any 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.
[0019] Additional objects, features and advantages will be apparent
in the written description which follows.
BRIEF DESCRIPTION OF THE DRAWINGS:
[0020] FIG. 1 is a simplified view of a typical building, in this
case a residential structure, shown in an elevated view to
illustrate the placement of the surrounding perforated conduit and
connecting grey water lines which make up a portion of the
foundation stabilization system of the invention.
[0021] FIG. 2 is a simplified piping schematic of the system of the
invention which uses grey water from a building to maintain a
constant moisture content in the soil surrounding the building
foundation.
[0022] FIG. 3 is a partial, sectional view of a portion of the
building foundation of the building shown in FIG. 1 showing the
placement of the component parts of the system of the
invention.
[0023] FIG. 4 is an isolated view of a portion of the sanitary
sewer conduit of the building, the sewer conduit being connected to
the perforated conduit which surrounds the building foundation by
an overflow conduit, the overflow conduit also containing a check
valve.
DETAILED DESCRIPTION OF THE INVENTION
[0024] The preferred version of the invention presented in the
following written description and the various features and
advantageous details thereof are explained more fully with
reference to the non-limiting examples included in the accompanying
drawings and as detailed in the description which follows.
Descriptions of well-known components and processes and
manufacturing techniques are omitted so as to not unnecessarily
obscure the principle features of the invention as described
herein. The examples used in the description which follows are
intended merely to facilitate an understanding of ways in which the
invention may be practiced and to further enable those skilled in
the art to practice the invention. Accordingly, the examples should
not be construed as limiting the scope of the claimed
invention.
[0025] In describing the present invention, reference will be had
to the terms "black water" and "grey water." "Black water" is a
term dating back until at least the 1970's used to describe water
which contains fecal matter and urine. It is also referred to as
brown water, foul water or sometimes simply as sewage. It is
distinct from "grey water," or sullage, which is generally
understood to be the residue from washing processes. Thus, water
coming from domestic equipment, other than toilets, e.g., bathtubs,
showers, sinks, etc., is generally referred to as "grey water." It
is preferably kept separate from black water, e.g., which comes
primarily from toilets. Separation of black water and grey water is
commonly employed in new construction today and is present in
almost all new "ecological" buildings.
[0026] Turning now to FIG. 1 of the drawings, there is shown a
building, in this case a typical residential dwelling designated
generally as 11. The building 11 has a roof 18, sidewalls 19 and a
foundation 21. The building is shown in phantom lines and in an
elevated manner in order to more clearly illustrate the foundation
moisture control system of the invention which includes the French
drain 13 and plurality of grey water conduits 15, as will be
explained in greater detail. The foundation of the building 11 is
surrounded by a soil perimeter (shown generally at 17 in FIG. 3).
FIG. 3 also shows a section of the building wall 19 supported on
the concrete foundation 20 which is separated from a sand fill 20
by a plastic vapor barrier material 22.
[0027] FIG. 2 is intended to be representative of a plumbing layout
of a typical residential dwelling structure. While the invention
will be described with respect to a residential dwelling structure,
it will be understood that the principles employed could be
utilized in the case of a commercial building structure, or any
other suitable structure where the foundation is built upon
expansive soils. With reference to FIG. 2, the particular plumbing
arrangement of the building includes a laundry sink 23, a washer
25, a kitchen sink 27, a dishwasher 29, a pair of lavatories 31,
37, a tub 35, a pair of toilets 33, 39, and a shower 41. As shown
in FIG. 2, the sewage, sometimes referred to as "black water" is
directed through sewer conduits 43, 45 and 47 to the sanitary sewer
line 49 outside the structure.
[0028] With reference now to FIGS. 2 and 3, the foundation
stabilization system of the invention utilizes a "French drain"
which is dug around the complete outside perimeter of the
foundation. A French drain, rubble drain, rock drain, drain tile,
perimeter drain or land drain will be familiar to those skilled in
the relevant arts and is a term used to describe is a trench
covered with gravel or rock that redirects surface and groundwater
away from an area. French drains are often provided with perforated
hollow pipes along the bottom to quickly vent water that seeps down
through the upper gravel or rock. French drains are common drainage
systems, primarily used to prevent ground and surface water from
penetrating or damaging building foundations. The typical use of
the French drain is therefore opposite to the use to be described
in the instant building foundation stabilization system. That is,
the prior art use was typically to direct water away from the
foundation, basement, etc. However, in the present invention, the
French drain is used to direct water toward the soil immediately
adjacent the building foundation.
[0029] As best seen in FIG. 3, the French drain 51 includes a
perforated conduit 53 which is buried in a surrounding particulate
drainage material 55. The perforated conduit can be, for example, a
4 inch diameter PVC pipe which has been perforated on at least the
bottom side. The particulate drainage material 55 is contained in a
trench dug around the perimeter of the building foundation and can
be any conveniently available fill material which has the requisite
permeability to water, for example, sand, gravel or rock. The
particulate material 55, being pervious to water, allows water from
the perforated conduit 53 to pass through the particulate drainage
material and to enter the surrounding soil 17.
[0030] The preferred French drain also includes a filter fabric 57
which surrounds or envelops the particulate drainage material 55.
This can be, for example, a treated cloth or plastic mesh material
which helps to prevent the infiltration of soil into the
particulate drainage material but which allows the egress of water
from the particulate material into the surrounding soil.
[0031] As shown in FIG. 3, a deflector sheet 59 of a predetermined
width extends outwardly from the building foundation 20 over the
French drain 51 and into the surrounding soil 17, 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. The deflector sheet in the example
illustrated is 6 mil thick sheet of roll plastic.
[0032] As shown in FIG. 2, the perforated conduit 53 is connected
to various sources of "grey water" within the building structure by
a plurality of grey water conduits, such as conduits 63, 65, 67, 69
and 71.The grey water conduits allow grey water being discharged
from within the building to be directed 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. Any sewer water produced in the building continues to be
discharged through the separate fluid conduits 43, 45 and 47, to
the sanitary sewer conduit 49. The source of the grey water can
thus comprise a source selected from among the group consisting,
for example, 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. The sewage source can be, for example, from
a building toilet, dishwasher, or the like.
[0033] In the preferred foundation stabilization system of the
invention, the perforated conduit 53 is connected to the sanitary
sewer conduit 49 at at least one point by an overflow conduit (73
in FIGS. 2 and 4). The overflow conduit 73 is preferably provided
with some sort of check valve 75 which will accept 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. This would be
convenient, for example, in the situation where the owners of the
dwelling have an unusual number of guests which temporarily
overloads the grey water discharge. In the particular example
illustrated, the check valve 75 is a rubber duck bill valve which
opens in response to the flow of grey water only.
[0034] An invention has been provided with several advantages. The
foundation stabilization system of the invention is relatively
simple in design and economical to implement. It takes advantage of
the separation of black water and grey water to provide water to
the building foundation which would otherwise be wasted. The
average person is estimated to use 8-100 gallons of water per day
in a typical household. This would be 320 gallons of water each day
for a typical family of four. Subtracting 80 gallons a day for
toilets, this leaves some 240 gallons of water which can be put
back into the soil using the foundation stabilization system of the
invention. The municipality is now required to supply only about
1/4 of the water requirement that was previously needed. The system
also increases the amount of water going back to the aquifer,
providing a natural filter for the water, and also cutting down on
run-off.
[0035] While the invention has been shown in one of its forms, it
is not thus limited and is susceptible to various changes and
modifications without departing from the spirit thereof.
* * * * *