Device and method for foundation drainage

A drainage system to be installed against a foundation of a building. The drainage system includes a drainage board having a plurality of channels extending from a bottom side along a front face thereof, and a portion of filter fabric attached to a rear face of the drainage board that covers the front face of the drainage board. The plurality of channels comprise a plurality of left channels and a plurality of right channels that intersect to form a crisscross pattern.

CROSS REFERENCE TO RELATED APPLICATIONS

Not applicable.

SEQUENTIAL LISTING

Not applicable.

BACKGROUND OF THE DISCLOSURE

1. Field of the Disclosure

The present disclosure relates to a drainage system installed along an outer foundation surface of a building, the system including a drainage board and filter fabric attached thereto.

2. Description of the Background of the Disclosure

Building foundations typically require a sturdy footing and a vapor-proofed, reinforced concrete pad attached thereto, the footing sitting on a bed of compact crushed stone. There are currently a number of ways to vapor-proof a foundation, which typically involve either water-proofing or damp-proofing. Water-proofing is a treatment that prevents the passage of water under hydrostatic pressure, and damp-proofing is a treatment that generally prevents the passage of water in the absence of hydrostatic pressure. Hydrostatic pressure is a force that is exerted on a foundation by water that is in the ground, i.e., groundwater, that surrounds the foundation. Many foundations require at least one form of water-proofing or damp-proofing.

After installation of the foundation of a building, a builder typically damp-proofs the outer wall thereof. Historically, builders have applied one or more coats of unmodified asphalt to the exterior side of building foundation walls from the footings to slightly above grade, i.e. ground level. Asphalt comes in various forms suitable for brushing, rolling, squeegeeing, spraying, or toweling. Water-based asphalt emulsions have also been applied to damp substrates along foundations, including onto green concrete. Such emulsions can also be used for gluing extruded polystyrene foam insulation to foundation walls. Cutback asphalts, which are solvent based, have also historically been used for damp-proofing foundations.

Water-proofing is different than damp-proofing in that, while water-proofing also may involve the application of one or more layers of asphalt, it further includes reinforcement with one or more layers of fiberglass, cotton fabric, or an elastomeric membrane. Recently, the trend has been to apply spray liquids that cure to form elastomeric membranes, as these are cost effective, can be applied quickly to concrete or masonry, and cure to form seamless, self flashing membranes. However, successful application of spray-on liquids requires significant preparation of substrates, and the spraying surfaces must be clean and dry or else the final membrane can blister or pinhole. Further, water that interfaces with the sprayed-on elastomeric membrane may not flow down the membrane in a uniform fashion, which can cause pooling underground. Spraying liquids to waterproof a foundation is thus an expensive and imperfect solution to the problem of keeping water out of foundation walls.

Dimple sheeting can also be used for water-proofing. Dimple sheeting is a low cost water-proof membrane that doubles as a drainage mat and looks like an egg carton in profile. It is rolled over concrete, masonry, or wood foundations and tacked up with washered nails. It can be installed over substrates in any condition and is subsequently backfilled with dirt, clay, sand, etc. The dimple membrane repels water and forms air gaps against the basement wall that allows water to channel down to footing drains below the foundation. However, dimple sheeting may collapse or buckle under pressure created by the backfilled material, as the sheet is generally not more than a few millimeters thick.

In addition to vapor-proofing, an additional aspect of protecting a foundation is providing insulation. Many products currently exist as below-grade insulation panels. Currently, some products exist that provide both insulation and drainage. Referring to one such example, a panel exists that directs groundwater to perimeter drains without affecting the panel's R-value, which is a unit of thermal resistance for an insulation panel. The channels provided within the panel are covered by a spin-bonded filter fabric that admits water but keeps soil out. The water enters through the filter fabric and then drains down one or more vertical channels in the panel. However, while dirt, clay, and sand are generally kept from entering the channels by the filter fabric, the vertical channels may become clogged by material that makes it through the filter fabric, which can prevent water from properly flowing down the one or more channels cut out of the foam. Still further, the use of fabric has historically only involved the use of a single, taught piece of fabric, which typically becomes disturbed, torn, or ripped away by the backfill over time as the backfill settles. As a result, there is a need for a device including a water-proof, insulative board that has channels provided therein that will not clog due to sediment, and a filter fabric that will not, with proper installation, tear or rip, since the filter fabric prevents sediment from entering the channels of the drainage board.

Therefore, it would be desirable to have a system that addresses one or more of the drawbacks presented above.

SUMMARY

According to one aspect, a drainage system includes a drainage board having a plurality of channels extending from a bottom side along a front face thereof, and a filter fabric attached to a rear face of the drainage board that covers the front face of the drainage board. The plurality of channels include a plurality of left channels and a plurality of right channels that intersect to form a crisscross pattern.

According to another aspect, a drainage system includes a drainage board having a plurality of channels extending from a bottom side along a front face thereof, and a filter fabric attached to a rear face of the drainage board that covers the front face of the drainage board and includes a settling strip. The settling strip is a multi-layered portion of the filter fabric that is folded over a single layered portion of the filter fabric.

According to a different aspect, a method of utilizing a drainage system includes the steps of attaching filter fabric to a rear face of a drainage board, folding the filter fabric over a top side and a front face of the drainage board, forming a portion of the filter fabric into a settling strip, installing the drainage system against a wall of a foundation, and filling backfill against an outer surface of the filter fabric.

DETAILED DESCRIPTION OF THE DRAWINGS

The devices and methods disclosed herein relate generally to insulated drainage boards designed to assist in the reduction of hydrostatic pressure that exists around a building foundation when groundwater is present by allowing water to pass through a filter fabric into one or more drainage channels downward to a drain tile and pump system. The embodiments disclosed herein further provide a thermo barrier between the building foundation and the sediment that comprises the surrounding ground, which helps to maintain a stable temperature year-round while minimizing the effects of the freeze-thaw cycle. The devices and methods disclosed herein further reduce the potential for wall cracks and protect the waterproofing membrane, i.e., the filter fabrics, from damage during backfill and settling of the ground.

FIGS. 1-6generally depict a drainage system20as described herein. The drainage system20includes a drainage board22, which may be formed from fiberglass, plastic fibers, natural fibers, compressed foam beads, foam boards, which may be made, e.g., from extruded polystyrene, polyisocyanurate, phenolic, polyurethane, or cementitious material. The drainage board22may have an R-value of between about 1 and about 15 or between about 5 and about 12 or between about 8 and about 11 or about 10. In one embodiment, the drainage board22comprises expanded polystyrene foam. In another embodiment, the drainage board22comprises extruded polystyrene foam (XPS). In still another embodiment, the drainage board22comprises polyisocyanurate, which may include a layer of foil provided thereon. In a further embodiment, the drainage board22comprises expanded polystyrene foam, which may be manufactured by expanding spherical beads in a mold, and using heat and pressure to fuse the beads together.

Turning toFIG. 1, a front elevational view of the drainage board22is illustrated. The drainage board22is defined by a left side24, a right side26, a top side28, a bottom side30, a front face32, and a rear face34(seeFIGS. 2, 5, and 6). In some aspects, the sides,24,26,28,30, and the faces32,34are generally substantially planar. The drainage board may be rectangular shaped and, in one aspect, may be square shaped. The left side24and the right side26may have a height dimension H of between about 1 feet and about 22 feet, or between about 6 feet and about 16 feet or about 8 feet Further, the bottom side30and the top side28may have a width dimension W of between about 1 foot and about 10 feet, or between about 2 feet and about 8 feet or about 4 feet. In some embodiments, the drainage board22may have a triangular or trapezoidal or other shape.

The drainage board22includes a plurality of channels40formed within the front face32. In one aspect, the channels40generally crisscross the drainage board22, forming diamond shaped (or 90 degree offset square shaped) portions42having a plurality of corners44. In one aspect, the channels40may be pre-formed in the drainage board22. In another aspect, the channels40are cut out of the drainage board22with a saw or another machining device. In some embodiments, the portions42have straight sides, and, thus, the corners44are sharp. In other embodiments, the corners44are rounded such that the sides may be curvilinear. In some embodiments, the portions42are generally the same shape excluding the portions near the left side24, right side26, top side28, or bottom side30. In other embodiments, the portions42have different shapes. In still further embodiments, the portions42are generally the same shape, but are of differing sizes. As one of ordinary skill in the art would recognize, in any embodiment disclosed herein, the greatest thickness of the drainage board22may be along one of the portions42, while the thinnest thickness may be along a portion of the channels40.

Referring toFIG. 1, in a preferred embodiment, the channels40include left channels46and right channels48that extend upward from the bottom side30of the drainage board22at an incline relative to a direction defining the height H, i.e., in a left direction and a right direction, respectively. The left channels46and the right channels48intersect at a plurality of intersection points50. In some embodiments, the left channels46and the right channels48are defined by straight lines between intersection points50. In other examples, the left and right channels46,48may be formed by zigzag lines between intersection points50. In other embodiments, the left and right channels46,48may be defined by curved lines between intersection points50. For example, in some embodiments, the left channels46and the right channels48are defined by sinusoidal-type waves either between intersection points50or along at least a portion of the front face32.

Still referring toFIG. 1, wherein the diagonal channels40are formed from left and right channels46,48, groundwater that enters the channels46,48flows downward toward the bottom side30due to gravity. The channels46,48are formed in such a way that if a blockage52(seeFIG. 3) occurs at one point, rather than water building up toward the top side28, as water would in a drainage board having only vertical, non-intersecting channels, the water can still flow through the channels40around the blockage52. In the disclosed embodiments, and still referring toFIG. 1, the left and right channels46,48are formed in such a way that the intersections thereof form an angle θ of about 90 degrees. However, in other embodiments, the angle θ may be acute, and may be between about 5 degrees and about 89 degrees, or between about 20 degrees and about 70 degrees, or about 50 degrees. In other embodiments, the angle θ may be obtuse, and may be between about 91 degrees and about 175 degrees, or between about 110 degrees and about 160 degrees, or about 125 degrees. In one aspect, the drainage system20may be made from 2 inch extruded polystyrene. In that instance, the system20may be cut with a table saw having a plurality of blades, e.g., 60 blades, and the channels46,48may be created by running the drainage board22through the table saw twice in 90° offset passes.

Still further, in other embodiments, the angle θ may be different along different parts of the front face32of the drainage board22. For example, in some embodiments, the angle θ may be smaller toward the top side28of the drainage board22, and may be larger toward the bottom side30of the drainage board22. In such an embodiment, the channels40may emanate from a singular point (not shown) centered along the bottom side30of the drainage board22such that the groundwater flows to the singular point or only a few points. The angle θ may be modified along the front face32of the drainage board22in response to a number of considerations, such as the desired strength, insulation coefficient, and drainage rate of the drainage board22. In still further embodiments, vertical channels (not shown) may be included that intersect the left and right channels46,48, e.g., at the intersection points50or at other locations along the channels46,48, to allow for more drainage of ground water.

As illustrated, a plurality of entryways60are defined by cutouts within the drainage board22. The entryways60are formed to allow water to enter the channels46,48and, due to gravity, flow toward the bottom side30of the drainage board22. It also will be appreciated by one of ordinary skill in the art that water may enter the channels at other points along the height of the drainage board22. As one of ordinary skill in the art would recognize, in a preferred embodiment, the bottom side30and the top side28of the drainage board22are mirror images of one another, and can be generally interchanged. As a result, the entryways60may also be exits62for the ground water depending upon the orientation of the board22. However, in some embodiments, as shown inFIG. 1, the top side28may have more entryways60than the bottom side30has exits62to allow more entry points for the ground water, or vice versa. The entryways60and exits62may be defined by the height of the drainage board22, the tooling of the device that cuts away the channels46,48, and the available space along the front face32of the drainage board22. In other embodiments, more or fewer entryways60may be included in response to considerations such as the hydrostatic pressure at the location of the foundation, the amount of water that is expected to drain through the drainage board22, or any other consideration known to those of ordinary skill in the art.

As seen inFIG. 2, a thickness of the drainage board is defined by a thickness T. The thickness T may be between about 0.5 inches and about 5 inches, or between about 1 inch and about 4 inches, or between about 1.5 inches and about 3 inches, or about 2 inches. A depth D of the channels40is also illustrated inFIG. 2. The depth D may be between about 1/16 inch and about 1 inch, or between about 2/16 inch and about 13/16 inch, or about 5/16 inch. The depth D of the channels may vary along the drainage board22depending on the desired rate of drainage of the ground water that enters the channels40. The channels40may also have a width W1(seeFIG. 3) of between about 1/16 inch and about 1 inch, or between about 2/16 inch and about 13/16 inch, or about 5/16 inch. The channels40may have a generally rectangular cross-sectional shape, or may have a semi-circular cross-sectional shape. The channels40may also have a triangular, pentagonal, heptagonal, or octagonal cross-sectional shape. Further, more or fewer channels40than shown in the illustrated embodiments may be included.

Still referring toFIG. 2, a top elevational view of another embodiment of the drainage board22is shown. As seen in that figure, a tongue70and a groove72may be included interchangeably along the left side24and the right side26of the drainage board22. The tongue70and groove72may act as a lock and key mechanism to allow two or more of the drainage boards22to interlock when placed into use. The tongue70may be have a generally trapezoidal cross-sectional shape, or may have another cross-sectional shape, such as a semi-circle, a triangle, a square, a rectangle, a pentagon, a hexagon, a heptagon, or an octagon. The groove72preferably has the same corresponding shape as the tongue70, which allows the one or more drainage boards22to interlock with one another. An adhesive or another securement mechanism may be included within the tongue70and groove72.

Now referring toFIGS. 4-6, the drainage board22is shown having a filter fabric80provided thereover. The filter fabric80generally has an outer surface82and an inner surface84. The filter fabric80may be a geotextile, which is a permeable textile material used to increase soil stability, provide erosion control and/or aid in drainage. In some embodiments, the filter fabric80is a natural fiber. In other embodiments, the filter fabric80is comprised of a synthetic polymer such as polypropylene, polyester, polyethylene, or a polyamide. The filter fabric80may be woven, knitted, or non-woven. In some embodiments, the filter fabric80is a non-woven geotextile. In non-woven embodiments, the filter fabric80may comprise US 80NW, US 90NW, US 100NW, US 120NW, US 160NW, US 180NW, US 205NW, US 300NW, or US 380NW. The filter fabric80may have a weight of between about 3.1 oz/sy (ounce per square yard) and about 16 oz/sy, or between about 4.0 oz/sy and about 8.0 oz/sy, or about 6.0 oz/sy. The filter fabric80may further have a tensile strength of between about 80 lbs and about 380 lbs, or between about 100 lbs and about 250 lbs, or about 160 lbs. Still further, the filter fabric80may be defined as having a water flow rate of between about 50 g/min/sf (gallons per minute per square foot) and about 150 g/min/sf, or between about 80 g/min/sf and about 140 g/min/sf, or about 110 g/min/sf.

Still referring toFIG. 4, the filter fabric80is shown cutaway to illustrate the channels40provided within the drainage board22underneath. As seen inFIGS. 5 and 6, the filter fabric80may cover the entire top side28and front face32of the drainage board22. Still further, and as will be discussed in greater detail below, the filter fabric80may be attached to the rear face34of the drainage board22. In some aspects, the filter fabric80is attached to the rear face34of the drainage board22approximately a foot below the top side28thereof. The filter fabric80may be attached to the rear face34with any one of staples, adhesion, rivets, pins, or any other method of coupling known to those of ordinary skill in the art. The filter fabric80may then be disposed over the top side28of the drainage board22and along the front face32thereof. In one aspect, the filter fabric80is not attached to the front face32of the drainage board22, which may allow the filter fabric80to slide up and down the front face32, as will be discussed in greater detail hereinafter below. In some aspects, and referring toFIG. 4, an end85of the filter fabric80nearest the bottom side30of the board22is unsecured. In some aspects, after installation of the system20, but before backfilling, the end85is even with the bottom side30of the board22, such that extra slack of the filter fabric80will exist after settling of the backfill.

Referring now toFIGS. 5 and 6, side elevational views of the drainage system20are shown, including the drainage board22and the filter fabric80. The drainage system20is shown in a non-backfilled state inFIG. 5and is shown in a backfilled state inFIG. 6. In the non-backfilled state, the filter fabric80is shown having two folds86, thereby creating a multi-layered settling strip88. In some embodiments, the system20includes more folds86. The settling strip88comprises an outer segment90, an intermediate segment92, and an inner segment94of the filter fabric80. As shown inFIG. 6, in the backfilled state, a lower portion87of the filter fabric80is pulled downward, thus the settling strip88disappears, due to being pulled along the front face32by backfill, thus, the segments90,92,94no longer exist in this state. In some aspects, the settling strip88does not completely disappear, but rather is only partially pulled down by the backfill.

In one aspect, the settling strip88may be created by lifting up a portion of the filter fabric80underneath itself, thereby creating the segments90,92,94. When the drainage system20has been installed, and before backfilling, the settling strip88may be held into place with one or more securement mechanisms96, which may include any one or more of tape, an adhesive, one or more pins, or one or more clips. In one aspect, the one or more securement mechanisms includes one or more strips of tape applied to the filter fabric80near the one or more folds86. In one aspect, the one or more securement mechanisms96include a plurality of staples applied near the folds86, which provide support to keep the settling strip88in place until backfill occurs. In one aspect, enough filter fabric80is provided along the lower portion87to cover the entire board22before backfill, i.e. to make up for the filter fabric that is used to create the settling strip88. In some aspects, a bottom end of the filter fabric is folded over one or more additional drainage features (not shown).

Still referring toFIGS. 5 and 6, the settling strip88is included to allow the lower portion87of the filter fabric80to slide against the front face32and settle downward when backfill is filled in against the drainage system20. When the drainage system20has been installed against the foundation of a building, a builder then refills the surrounding area with backfill, which may include sand, gravel, soil, clay, or any other material within the ground. When installing the backfill, the immediate filling and further settling of the ground material pulls downward against the filter fabric80, which creates tension in the filter fabric80. In order to avoid distortion, tearing, or other breakage of the filter fabric80due to this tension, the settling strip88provides for slack in the filter fabric80such that during backfill, and during the process of the settling of the surrounding ground materials, the filter fabric80does not become overly taught. As a result, the purpose of the filter fabric80, i.e. to prevent ground materials from entering the channels40of the drainage board22, can be achieved long after the process of backfilling has occurred.

Referring now toFIG. 7, a flow chart setting forth steps of a process700for utilizing the drainage system20disclosed herein is shown. Referring to step S1, the first step is to provide a board that can be used as the drainage board22. The board may be made of any one of the aforementioned materials. Next, at step S2, the channels40are formed in the drainage board22, e.g., with one or more saws or cutting devices. In one aspect, this step includes cutting the channels in a crisscross pattern, thereby creating the diamonds as discussed above. In another aspect, the board22may be provided with pre-formed channels, thereby combining steps S1and S2. At step S3, the filter fabric80is attached to the rear face34of the drainage board22. In an alternative embodiment, the filter fabric80may be attached to the top side28or the front face32of the drainage board22. At step S4, the filter fabric80is folded over the top side28and the front face32of the drainage board22. At step S5, the settling strip88is formed by folding a portion of the filter fabric80under itself twice over, thereby creating the segments90,92,94. Next, the settling strip88is optionally secured using one or more securement mechanisms96, which may be tape, staples, an adhesive, clips, or pins. At step S6, the drainage system20is installed against a wall of a foundation (not shown). At step S7, backfill is provided against the filter fabric80, and, thus, a downward force is applied to the outer surface82of the filter fabric80and to the lower portion87of the filter fabric in particular. Initially and/or over time, this force pulls the filter fabric80downward, either immediately after replacement of the backfill or during settling of the backfill, until the filter fabric80no longer includes the settling strip88or until settling of the backfill is complete.

Some benefits of the drainage system20as described hereinabove will now be discussed. The extended filter fabric80, i.e., inclusion of the settling strip88, provides long term protection against soil clogging within the channels40of the drainage board22. Further, the combination of insulation due to the preferred R-10 insulation rating, the drainage board22having crisscrossed channels40, and the filter fabric80all in one provides cost savings for contractors, builders, and home and business owners. Further, due to the thickness of the drainage board22, the drainage system20will not buckle and slide down the wall of the foundation as the backfill settles, as other drainage systems do. The configuration of the channels40described herein relieves hydrostatic pressure build up, and protects damp-proofing systems that may be provided along the rear face34of the drainage board, or in some other location along the foundation. In some embodiments, the tongue70and groove72configuration of the drainage board22assists in proper installation of the drainage board22and allows for sealed joints. Previous drainage products made of fiberglass or mineral wool cannot stand up to compressive loads of compacted backfill without deforming and losing most of their drainage and insulating capacity.

Any of the embodiments described herein may be modified to include any of the structures or methodologies disclosed in connection with different embodiments. Further, the present disclosure is not limited to drainage board and/or filter fabrics of the types specifically shown and described. Still further, the drainage boards of any of the embodiments disclosed herein may be modified to work with various types of filter fabrics consistent with the disclosure herein.

INDUSTRIAL APPLICABILITY