In a foundation assembly, a moisture barrier is placed on a footing and a foundation wall is on the moisture barrier. The moisture barrier thus isolates the foundation wall from the footing. The footing defines a keyway. The moisture barrier comprises a waterproof layer, a bottom layer attached to bottom side of the waterproof layer, and a top layer attached to the top side of the waterproof layer. The waterproof layer blocks passage of water therethrough. The bottom layer is for attaching the moisture barrier to the footing, and comprises a material that attracts water and binds to cement. The moisture barrier comprises a keyway portion sufficiently flexible and configured to fit the keyway in the footing. When the keyway portion fits to the keyway on the footing, it defines a secondary keyway for receiving a key portion of the foundation wall.

FIELD OF THE INVENTION 
     The present invention relates to footing barriers for foundation walls. 
     BACKGROUND OF THE INVENTION 
     Structural building walls, such as foundation walls, and interior walls can be damaged, or even fail, if exposed to water for a prolonged period of time. Water may be present in liquid or gas phase, such as in moisture or vapor form. 
     Small to moderate amounts of moisture typically can escape without causing damage. Recent building techniques, however, have been sealing walls with vapor barriers. At the same time such seals can trap even small amounts of moisture, which in turn may cause damage. 
     For example, it is now increasingly common to thermally insulate basement walls, and consequently to install moisture and vapor barriers on one or both sides of the walls. While the moisture and vapor barriers can prevent outside moisture from getting into the walls through the sides, they can also trap any moisture that has migrated into the wall. 
     Leakage water can be drained through drain conduits, as described, for example, in U.S. Pat. No. 5,845,456 to Read, issued Dec. 8, 1998 (“Read”). 
     However, even when drainage is used, water damage can still occur in building walls, particularly basement walls with full height thermal insulation. 
     SUMMARY OF THE INVENTION 
     In accordance with an aspect of the present invention, there is provided a moisture barrier for isolating a foundation wall from a footing in a building. The moisture barrier comprises a waterproof layer for blocking passage of water through the moisture barrier, the waterproof layer having a bottom side and a top side; a bottom layer attached to the bottom side of the waterproof layer, for attaching the moisture barrier to the footing, the bottom layer comprising a material that attracts water and binds to cement; and a top layer attached to the top side of the waterproof layer, for contacting the foundation wall, wherein the moisture barrier comprises a keyway portion, the keyway portion being sufficiently flexible and being configured to fit a keyway in the footing. The bottom layer may be permeable to a fluid comprising water and cement. The waterproof layer may comprise one or more polymers selected from polyethylene, polyvinyl chloride, polypropylene, polyester, polystyrene, polyamide, and ethylene vinyl acetate. The bottom layer may comprise polyethylene terephthalate, or a suitable polyester. The bottom layer may comprise a needle-punched fabric. The top layer may have an anti-slip to surface. The top layer may comprise polypropylene or polyethylene terephthalate. The top layer may comprise a fabric material. The fabric material may comprise a spun-bonded, needle-punched, chemically bonded, or thermally-bonded fabric. The top layer may comprise indicia delineating the keyway portion. 
     In another aspect of the present invention, there is provided a foundation assembly. The foundation assembly comprises a footing defining a keyway; a moisture barrier on the footing, the moisture barrier comprising a keyway portion fit to the keyway on the footing and thus defining a secondary keyway; and a foundation wall on the moisture barrier, the foundation wall having first and second sides and a bottom, the bottom comprising a key portion received in the secondary keyway, wherein the moisture barrier comprises a waterproof layer for blocking passage of water through the moisture barrier, the waterproof layer having a bottom side and a top side; a bottom layer attached to the bottom side of the waterproof layer and binding the moisture barrier to the footing; and a top layer attached to the top side of the waterproof layer and in contact with the foundation wall. The foundation assembly may comprise a vapor barrier attached to the interior side of the foundation wall and a damp proofing attached to the exterior side of the foundation wall. The moisture barrier may be a moisture barrier described herein. The footing may comprise concrete. The foundation wall may comprise concrete. 
     In a further aspect of the present invention, there is provided a building comprising the foundation assembly described herein. 
     In another aspect of the present invention, there is provided a method of installing a foundation wall having a bottom key portion. The method comprises forming a footing, the footing defining a keyway; placing a moisture barrier on the footing, the moisture barrier comprising a flexible keyway portion fit to the keyway and thus defining a secondary keyway for receiving the bottom key portion of the foundation wall; and disposing the foundation wall on the moisture barrier on the footing to support the foundation wall with the footing, with the bottom key portion of the foundation wall being received in the secondary keyway, wherein the moisture barrier comprises a waterproof layer for blocking passage of water through the moisture barrier, the waterproof layer having a bottom side and a top side; a bottom layer attached to the bottom side of the waterproof layer and binding the moisture barrier to the footing; and a top layer attached to the top side of the waterproof layer and in contact with the foundation wall. The method may comprise, sequentially, forming a body of wet concrete; attaching the moisture barrier to a top surface of the body of wet concrete; and disposing the foundation wall on the moisture barrier. The wet concrete may be fully cured to form the footing after the attaching the moisture barrier to the body of wet concrete. The method may further comprise, after the moisture barrier is attached to the body of wet concrete and before the wet concrete is fully cured, pressing a section of the moisture barrier against the wet concrete to form the keyway and the secondary keyway. The foundation wall may comprise concrete. The moisture barrier may be a moisture barrier described herein. 
     Other aspects and features of the present invention will become apparent to those of ordinary skill in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the figures, which illustrate, by way of example only, embodiments of the present invention, 
         FIG. 1  is a perspective view of a foundation assembly, exemplary of an embodiment of the present invention; 
         FIG. 2  is an elevation side view of a moisture barrier, exemplary of an embodiment of the present invention; 
         FIG. 3  is a top plan view of the moisture barrier of  FIG. 2 ; 
         FIG. 4  is a perspective view of a footing formed of poured concrete; 
         FIG. 5  is a perspective view of the moisture barrier of  FIG. 2  being attached to the poured concrete of  FIG. 4 ; 
         FIG. 6  is a perspective view of the moisture barrier attached to the poured concrete of  FIG. 4 ; 
         FIG. 7  is a cross-sectional view of a moisture barrier and a footing formed by applying pressure to the structure of  FIG. 6 ; 
         FIG. 8  is a cross-sectional view of a foundation wall installed on top of the moisture barrier and footing of  FIG. 7 ; and 
         FIG. 9  is a partial cross-sectional view of a basement in a building. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  depicts a foundation assembly  100  in a building, exemplary of an embodiment of the present invention. Assembly  100  includes a foundation wall  102  (also referred to as stem wall), a footing  104  (also referred to as a footer) for supporting foundation wall  102 , and a moisture barrier  106  (also referred to as footing barrier) sandwiched between foundation wall  102  and footing  104  for isolating them, exemplary of an embodiment of the present invention. Footing  104  may be disposed directly on soil  107 . 
     Soil  107  and other unreferenced parts in  FIG. 1  are depicted to provide context, but do not form part of assembly  100 . In different embodiments, assembly  100  may include other components (either shown or not shown in  FIG. 1 ) that may be used in a building construction as can be understood by those skilled in the art, such as flooring components, ceiling components, structural reinforcing components, thermal insulation components, finishes, or the like. 
     Foundation wall  102  has a side  108  and a bottom  110 . A key  112  may protrude from bottom  110  for engaging footing  104 . Key  112  may extend along a longitudinal central portion of the bottom surface of bottom  110 . Foundation wall  102  may be made of any suitable material for foundation walls or stem walls. Typically, foundation wall  102  is formed mainly of poured concrete. In different embodiments, foundation wall may also be formed of wood, a concrete block, synthetic or composite materials, or the like. Foundation wall  102  may have any dimension, shape, or structure. 
     Additional features and structures, such as reinforcing materials, panels, studs, layers including thermal insulation layers and moisture/vapor barriers, drywalls, pipes, finishing, proofing, or the like (not shown) may be included in, or attached to, foundation wall  102 , as may be appropriate depending on the particular application. For example, foundation wall  102  may form part of a basement wall (not shown in  FIG. 1 , but see  FIG. 9 ). 
     Foundation wall  102  may be pre-fabricated or constructed at the building site as further described below. 
     Footing  104  has a top surface  114  for supporting moisture barrier  106  and, indirectly, foundation wall  102 . A keyway  116  may be provided at top surface  114  of footing  104 . Key  112  and keyway  116  are aligned and complementary in shape to tightly engage each other, to provide positional stability during construction and in the assembled structure. Footing  104  may be made of any suitable footing material. For example, footing  104  may include concrete. Additional features, rebars, reinforcements, or the like (not shown) may be included in or attached to footing  104 . Footing may be pre-fabricated or constructed at the building site, as will be further described below. Typically, footing  104  is formed of poured concrete on site. Footing  104  may be exposed to water such as moisture during normal use after construction, for example, by capillary wicking. For example, footing  104  may be directly placed on the underlying soil, which can be wet for prolonged periods during use. Some footing materials, such as concrete, can potentially allow passage of water, such as by capillary action. 
     It has been recognized that, if foundation wall  102  is in direct contact with footing  104 , a possible cause of water damage in the building wall that includes foundation wall  102  is water accumulation around foundation wall  102  near footing  104  due to capillary wicking through footing  104 . For example, when footing  104  is made of concrete, small pores and fissures (not separately depicted in  FIG. 1 ) present in the concrete can serve as capillary conduits and water can pass (rise up) through these pores and fissures of the concrete due to capillary action (also referred to as wicking). When the soil  107  surrounding footing  104  is wet, water from the wet soil  107  can continuously pass through footing  104  and reach the interface region between foundation wall  102  and footing  104 . In the absence of a moisture barrier (such as moisture barrier  106 ) disposed between foundation wall  102  and footing  104 , water can come into contact with, and accumulate around, foundation wall  102  near footing  104 . The water can further rise up along foundation wall  102 , for example, when foundation wall  102  is made of concrete or another material that can itself transport water by capillary action. When a vapor barrier (not shown in  FIG. 1 , but see  FIG. 9 ) is applied to an entire side of foundation wall  102 , the moisture rising from footing  102  can be trapped by the vapor barrier. As a result, the building wall or certain wall structures in the building wall around foundation wall  102  can become damaged, or even fail, due to prolonged exposure to water. As can be understood by those skilled in the art, installing a drainage system, such as the drainage system described in Read, near foundation wall  102  and footing  104  will not eliminate capillary action in footing  104 , and will not prevent water from reaching foundation wall  102  through footing  104  by capillary action, when water is available in the soil  107  surrounding footing  104 . 
     Conveniently, the potential damage and failure of the building wall caused by capillary wicking of water through footing  104  can be eliminated by isolating foundation wall  102  and footing  104  with moisture barrier  106 , as illustrated in  FIG. 1 . Moisture barrier  106  blocks (breaks) the capillary path to foundation wall  102 , thus preventing water from reaching foundation wall  102  by capillary wicking through footing  104 . 
       FIGS. 2 and 3  illustrate a moisture barrier  200 , exemplary of an embodiment of the present invention that can be used to form moisture barrier  106 . 
     Moisture barrier  200  includes a flexible, multi-layered sheet, which has a bottom layer  202 , a top layer  204  and a middle layer  206  sandwiched between bottom layer  202  and top layer  204 . 
     Bottom layer  202  has a bottom surface  208  and a top surface  210 , and is adapted for reliable attachment, or binding, to footing  104 . Bottom layer  202  may be attached and bonded to footing  104  through any suitable binding mechanism, including physical or chemical binding. For example, bottom layer  202  may be made of a material that attracts water and binds to cement. The material may be permeable to a fluid mixture of water and cement so that it can absorb water and cement from the wet concrete used to form footing  104 . Bottom layer  202  may be formed of a needle-punched fabric. Bottom surface  208  of bottom layer  202  may also be adhesive to top surface  114  of footing  104 . Bottom layer  202  may be formed from a suitable hydrophilic material, such as polyethylene terephthalate (PET), and may be provided as a fabric, either woven or non-woven. 
     In one embodiment, a PET needle-punched fabric may be used to form bottom layer  202 . In other embodiments, other geotextiles may be used. A suitable polyester material may be used. The geotextile material may include a needle-punched, heat bonded, or woven fabric. The thickness of bottom layer  202  may be from about 0.2 mm to about 5 mm. 
     Top layer  204  has a bottom surface  212  and a top surface  214 . Top layer  204  is formed of a material selected to provide sufficient friction (traction) on the top surface  214  to prevent slippage (anti-slip). When the top surface  214  of layer  204  provides sufficient friction or traction to reduce or prevent slippage on the surface, it allows the workers to safely walk or stand on moisture barrier  200  during construction of the building. Top surface  214  of top layer  204  may also provide sufficient traction for conveniently writing thereon with a chalk, as the chalk is unlikely to slip on an anti-slip surface. This can allow a worker to conveniently make marks on the moisture barrier, for example, to draw lines to mark positions and directions of keyways, or placement of concrete or formwork for pouring concrete. The material for top layer  204  may also be selected so that it can withstand the rough working conditions on a construction site. Top layer  204  may be formed of polypropylene (PP) or another suitable polymer such as PET, and may be in the form of a spun-bonded fabric. Top layer may also be formed of a needle-punched, chemically-bonded, thermally(heat)-bonded, or woven fabric. While different types of fabric materials may be used, spun-bonded fabric may be relatively inexpensive to produce, and can still provide sufficient strength, durability, and anti-slip properties appropriate or required for the intended use. Spun-bonded fabric can conveniently allow marking thereon with a chalk and can provide an anti-slip surface. The thickness of top layer  204  may be from about 0.2 mm to about 5 mm. 
     Middle layer  206  is formed of a flexible waterproof material that blocks passage of both liquid water and water vapor by capillary wicking. The waterproof material has a permeability rating that is considered suitable for use as a vapor barrier or vapor retarder according to industry standards. For example, the permeability rating of the middle layer may be less than 57 ng/s·m 2 ·Pa based on the ASTM-E96 Water Vapor Transmission Test. A suitable waterproof material is polyethylene. Other suitable polymer materials may include polyvinyl chloride (PVC), polypropylene, polyester, polystyrene, polyamide, ethylene vinyl acetate (EVA), or the like. A combination of different materials may also be used in middle layer  206 . The thickness of middle layer  206  may be from about 0.1 mm to about 3 mm. 
     Layers  202 ,  204 ,  206  of moisture barrier  200  may be bonded to each other in any suitable manner. For example, the layers may be chemically bonded or physically bonded, such as being thermally bonded, glued, stitched or stapled together. 
     In this embodiment, moisture barrier  200  is pliable, adhesive to concrete, and can prevent capillary wicking therethrough. 
     Optionally, moisture barrier  200  may also provide thermal insulation. 
     Moisture barrier  200  may be sufficiently flexible so that it can be rolled to form a roll, and can conform to the top surface of footing  104  and bottom surface of foundation wall  102 , which may not be perfectly flat. 
     For example, when key  112  and keyway  116  are to be provided on foundation wall  102  and footing  104  respectively, a corresponding central section  220  (referred to as keyway section  220 ) of moisture barrier  200  should be sufficiently flexible to conform to the shapes of key  112  and keyway  116  to allow reliable engagement therebetween. Keyway section  220  may have a width similar to, or greater than, the width of keyway  116 . Alternatively, moisture barrier  200  may be made of the same materials across its width and is sufficiently flexible to allow keyway formation and key/keyway engagement. To assist keyway formation and alignment of foundation wall  102  and footing  104  during construction or installation, physical markings may be provided on moisture barrier  200  to mark the intended key/keyway lines. Such markings may be provided by inked lines, different colors, different material surface textures, or any other suitable indicia. 
     For convenient use, moisture barrier  200  may have a substantially rectangular shape, as depicted in  FIG. 3 , and may be sized to cover the full width of a section of surface  114  of footing  104 . For example, the moisture barrier  200  may have a width of about 0.45 m. Moisture barrier  200  may be provided in a roll with a length of, for example, about 25 m. The width of moisture barrier  200  may be selected to match the width of footing  104 , or to be at least as wide as the thickness of foundation wall  102 . 
     However, in different applications, the size and shape of moisture barrier  200  may vary and may be different from those depicted in the drawings. 
     For convenient use, the top and bottom surfaces of moisture barrier  200  may have different, identifiable colors or readily noticeable labels or markings to assist users to readily determine which side is the top side and which side is the bottom side. For example, the top side may have a blue color and the bottom side may have a grey color. A side may also have printed indicia that indicate whether it is a top side or bottom side. 
     Foundation assembly  100  may be constructed as part of a building, as illustrated in  FIGS. 4 to 8 , according to an exemplary embodiment of the present invention. 
     As shown in  FIG. 4 , a body of poured concrete  300  for forming footing  102  is initially formed directly on underlying soil (not shown). Formwork or another suitable type of mold may be provided to define the shape of poured concrete  300 . Wet concrete, which includes cement and water, may be poured into the formwork or mold. Suitable concrete and cement materials may be selected depending on the particular application. Additional materials such as reinforcing materials (not shown) may be included in poured concrete  300 . For example, steel wires or rebars may be embedded in poured concrete  300 . The top surface  302  of poured concrete  300  is exposed and may be leveled and treated as appropriate, as can be understood by those skilled in the art. While it is not necessary for the top surface of poured concrete  300  to be completely flat before applying moisture barrier  200 , it may be convenient for later processing if top surface  302  is generally flat. 
     As illustrated in  FIG. 5 , while the concrete material in poured concrete  300  is still wet and deformable (i.e. before it is cured), moisture barrier  200  is applied to top surface  302  of poured concrete  300  with bottom layer  202  in contact with poured concrete  300 . In some applications, installation of moisture barrier  200  may begin as soon as poured concrete  300  has been poured and leveled. 
     When bottom layer  202  of moisture barrier  200  is in contact with wet concrete, it can attract and absorb water, with some dissolved cement material or suspended cement particles. Thus, as the concrete is cured, bottom layer  202  will be securely attached to (bonded to or even partially embedded in) the resulting solid concrete. 
     While only one piece of moisture barrier  200  is depicted in  FIG. 5 , multiple pieces of moisture barriers may be used to cover a section of the footing concrete, or the entire footing concrete. For example, multiple pieces of moisture barrier  200  may be placed side by side or head to toe. The edges of adjacent moisture barriers  200  may overlap by a sufficient length to prevent leakage of water through the gaps between the pieces. For example, in one embodiment, the adjacent pieces may overlap by about 1 to about 2 cm. 
     Further, while as depicted, the entire top surface  302  is covered, in different applications, only a portion of the top surface of the footing may be covered with a moisture barrier, as long as the footing and the foundation wall is isolated from each other by the moisture barrier. In such cases, moisture barrier(s)  200  may be applied to cover the portions of poured concrete  300  that is to be directly underneath, or in proximity to, foundation wall  102 . For example, when a keyway will be used, moisture barrier  200  may be applied along the desired keyway line. 
     At the end of application of moisture barrier  200 , any extra portion of moisture barrier  200  may be conveniently cut with a cutting tool, such as a utility knife. 
     Sometimes, a projection, such as a rebar (not shown), may project from top surface  302  of poured concrete  300 . In such a case, an opening may be provided in moisture barrier  200  to allow the projection to pass through during installation. The opening may be conveniently provided, for example, by forming an “X” shaped cut in moisture barrier  200  at the location where the projection is to pass through. 
     As the bottom surface of moisture barrier  200  can bind or adhere to wet concrete surface, it is not necessary to hold down the moisture barrier with weight during installation. 
     Further, bottom layer  202  of moisture barrier  200  is permeable to and can absorb fluid footing materials, such as water and small cement particles suspended in water, from poured concrete  300 , and the absorbed materials will facilitate binding between poured concrete  300  and moisture barrier  200  when the concrete is dried and cured, as discussed earlier. Conveniently, the absorbed material also helps to stabilize moisture barrier  200  on top of poured concrete  300  by increasing its weight. 
     As can be appreciated, as moisture barrier  200  can securely attach to, or bond with, footing  104 , it will not be easily displaced during subsequent construction process, such as during gravel placement, which may involve throwing gravel or crushed-rock at high speeds towards footing  104  with a “stone slinger” machine. 
     In the present embodiment shown in  FIGS. 4 to 8 , a keyway is to be formed in poured concrete  300 . As illustrated in  FIG. 6 , the keyway may be formed by applying downward pressure along markings that indicate the keyway section  220  on moisture barrier  200 . The pressure may be applied using any suitable technique. For example, a block of solid material (not shown) with a suitable size may be used. In some cases, a 2×4 wooden bar may be conveniently used to apply the pressure. 
     In some applications, the keyway section  220  marked on moisture barrier  200  may conveniently assist the user to determine the position and direction of the keyway line. For example, the side edges of moisture barrier  200  may be aligned with fixed markers and the keyway is then formed based on the direction and position of the keyway section  220 . 
     As shown in  FIG. 7 , the resulting concrete body forms footing  104  with keyway  116 . Moisture barrier  200  adheres to the wet concrete surface of footing  104  and conforms to the shape of keyway  116 , thus forming moisture barrier  106 . 
     In the present embodiment, the concrete in footing  104  is fully cured only after attachment of moisture barrier  200  to poured concrete  300  and formation of keyway  116 . 
     As illustrated in  FIG. 8 , foundation wall  102  is next disposed on top of moisture barrier  106 . Foundation wall  102  may be fabricated off-site and installed after footing  104  is cured. Alternatively, foundation wall  102  may be built on-site and construction of foundation wall  102  may begin before or after footing  104  is fully cured. 
     For example, when foundation wall  102  is made of concrete, a formwork (not shown) for forming foundation wall  102  may be constructed or installed, and the concrete for foundation wall  102  may be poured in to the formwork after keyway  116  has been formed, and while the concrete in footing  102  is still curing. 
     A foundation assembly described herein, such as foundation assembly  100  of  FIG. 1 , may be used, as illustrated in  FIG. 9 , to form a part of a building  400 , which may be a residential, public, or commercial building. Building  400  may include a basement  402 , and assembly  100  may form a part of basement  402 , as depicted in  FIG. 9 . Basement  402  is partially underground and has a side wall  404 , which includes foundation wall  102 , damp proofing  406  attached to the exterior side of foundation wall  102 , an interior insulation layer  408  and a vapor barrier  409  attached to the interior side of foundation wall  102 , and frame/stud  410 . Damp proofing  406  may include any suitable material for damp proof, such as in the form of a water proof sheet or tar. Insulation layer  408  provides thermal insulation. Vapor barrier  409  may be formed of any suitable waterproof material. Basement  402  also has a floor  412 , which includes a concrete floor slab  414 . Foundation wall  102  is supported on footing  104  indirectly and is isolated from footing  104  by moisture barrier  106 . A drainage system  416  may also be provided as part of basement wall  404 . 
     As can be appreciated, damp proofing  406 , vapor barrier  409 , and drainage system  416  can reduce the risk of water damage in basement wall  404 , by preventing water from entering into wall  404  through the sides and by collecting water from surrounding soil  418  and interior moisture from inside wall  404 . As depicted in  FIG. 9 , a large portion of side wall  404  may be in contact with surrounding soil  418 . To fully protect foundation wall  102  from water attack from surrounding soil  418 , damp proofing  406  may need to extend over the full height of foundation wall  102 . In such cases, the risk of water accumulation and water damage within side wall  404  can be significantly further reduced by the presence of moisture barrier  106 , as moisture barrier  106  between foundation wall  102  and footing  104  can conveniently prevent water accumulation in the foundation wall  102  through footing  104  by way of capillary wicking. If moisture barrier  106  is absent, water may pass from soil  418  to foundation wall  102  through footing  104  and any water accumulated around foundation wall  102  between damp proofing  406  and vapor barrier  409  will not be able to escape and will be likely trapped inside side wall  404  for a long period of time, due to blockage by damp proofing  406  and vapor barrier  409 . 
     Building  400  may be constructed and may include parts and components as described in the literature or as used in known practices, with the modifications necessary to implement features of the exemplary embodiments disclosed herein. For example, the following literature references may be consulted for constructing building  400 :  Best Practice Guide: Full Height Basement Insulation , by Ministry of Municipal Affairs and Housing, 2008, available online at <http://www.ontario.ca/buildingcode> under Menu item “Publications”; “ Builder's Guide to Cold Climates”  by Joseph Lstiburek, Building Science Corporation, 2006 ; “Builder's Guide to Mixed - Humid Climates,”  by Joseph Lstiburek, Building Science Corporation, 2005 ; “Builder's Guide to Hot - Dry  &  Mixed - Dry Climates,”  by Joseph Lstiburek, Building Science Corporation, 2004 ; “Builder's Guide to Hot - Humid Climates,”  by Joseph Lstiburek, Building Science Corporation, 2005 ; “Performance Guidelines for Basement Envelope Systems and Materials,”  by Michael C. Swinton and Ted Kesik, National Research Council of Canada, 2005; and “ Builder's Foundation Handbook,”  by John Carmody and Jeffery Christian, Kenneth Labs, Oak Ridge National Laboratory, 1991. 
     As now can be understood, the embodiments described herein may be modified to suit the needs in different applications, as long as an effective moisture barrier is placed between the footing and the foundation wall supported by the footing to break the capillary path from the footing to the foundation wall. Embodiments of the present invention may have applications in various buildings or construction processes where water damage to the foundation wall is of concern. 
     Embodiments of the present invention are further illustrated by the following non-limiting examples. 
     EXAMPLE 
     Working embodiments of moisture barrier  200  were produced in mass production. The produced sample moisture barriers were three-layer sheets, where the bottom layer was a needle-punched fabric made of polyethylene terephthalate; the top layer was a spun-bonded fabric made of polypropylene; and the middle waterproof layer was made of polyethylene. 
     The roll size for the production sheet is 0.45 m by 25 m. The expected lifetime of the sheet in soil at temperatures below 20° C. is 25 years or more. 
     EXAMPLE I 
     Sample moisture barriers were tested for water vapor transmission based on ASTM E96/E96M-05 Procedure A. The test conditions were: Procedure A (desiccant method at 23° C.); relative humidity, 50%; container material, aluminum; exposed area, 63.62 cm 2 ; composition of sealant, microcrystalline wax; testing period, one week. Representative test results are listed in Table I. 
     
       
         
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
             
           
               
                   
                 TABLE I 
               
               
                   
                   
               
               
                   
                 test 1 
                 test 2 
                 test 3 
                 Average 
                 S.D. 
                 % CV 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                 Specimens thickness 
                 1.40 
                 1.19 
                 1.19 
                   
                   
                   
               
               
                 (mm) 
               
               
                 Water vapor 
                 4.99 
                 6.91 
                 5.72 
                 5.87 
                 0.97 
                 16.5 
               
               
                 transmission 
               
               
                 (g/m 2  · 24 h) 
               
               
                 Permeance 
                 41.1 
                 56.9 
                 47.1 
                 48.4 
                 8.0 
                 16.5 
               
               
                 (ng/Pa/s/m 2 ) 
               
               
                   
               
             
          
         
       
     
     EXAMPLE II 
     Sample moisture barriers were also tested for tensile properties based on ASTM D882-02. The test conditions were: samples conditioned at 21° C., 65% R.H; apparatus used: Dynamometer, with Constant Rate of Extension (CRE) speed; 5 test specimens per direction cut with a die; type of grips, hydraulic grips (rubber coated); crosshead speed, 50 mm/min; grip separation (initial), 100 mm; test specimen width and length, 25.4 mm×152.4 mm. Representative test results for tensile strength in machine direction are listed in Table II. Representative test results for tensile strength in cross direction are listed in Table III. 
     
       
         
               
             
               
               
               
             
               
               
               
               
             
           
               
                 TABLE II 
               
             
             
               
                   
               
               
                 Tests in Machine Direction 
               
             
          
           
               
                   
                   
                 Elongation at tensile 
               
               
                   
                 Tensile strength (kN/m) 
                 strength (%) 
               
               
                   
                   
               
             
          
           
               
                   
                 test 1 
                 5.19 
                 72.6 
               
               
                   
                 test 2 
                 6.06 
                 81.1 
               
               
                   
                 test 3 
                 6.16 
                 50.3 
               
               
                   
                 test 4 
                 6.00 
                 59.7 
               
               
                   
                 test 5 
                 4.75 
                 63.2 
               
               
                   
                 Average 
                 5.63 
                 65.4 
               
               
                   
                 S.D. 
                 0.63 
                 11.9 
               
               
                   
                 % CV 
                 11.1 
                 18.2 
               
               
                   
                   
               
             
          
         
       
     
     
       
         
               
             
               
               
               
             
               
               
               
               
             
           
               
                 TABLE III 
               
             
             
               
                   
               
               
                 Tests in Cross Direction 
               
             
          
           
               
                   
                 Tensile strength 
                 Elongation at tensile strength 
               
               
                   
                 (kN/m) 
                 (%) 
               
               
                   
                   
               
             
          
           
               
                   
                 test 1 
                 2.13 
                 125.2 
               
               
                   
                 test 2 
                 1.55 
                 146.8 
               
               
                   
                 test 3 
                 1.13 
                 117.7 
               
               
                   
                 test 4 
                 2.12 
                 110.3 
               
               
                   
                 test 5 
                 1.53 
                 151.7 
               
               
                   
                 Average 
                 1.69. 
                 130.3 
               
               
                   
                 S.D. 
                 0.43 
                 18.1 
               
               
                   
                 % CV 
                 25.4 
                 13.9 
               
               
                   
                   
               
             
          
         
       
     
     EXAMPLE III 
     Sample moisture barriers were tested for impact resistance by the free-falling dart method, based on ASTM D1709-02, method B. The test conditions were: samples conditioned at 23° C., 50% R.H; Method B, staircase testing technique with a dart of 50.8 mm diameter head; weight used, 1348 g, 1396 g, 1444 g, 1492.7 g, 1541.1 g, 1589.5 g and 1638 g. A failure was recorded when the dart completely went through the sample sheet. A total of 20 specimens were tested. The weight increment was 48.3 g. The observed results were: impact failure weight, 1497 g; lowest weight with failure, 1396 g; and highest weight without failure, 1590 g. 
     EXAMPLE IV 
     Sample moisture barriers were tested to determine their resistance to water penetration based on the hydrostatic pressure test of ISO 811-1981. The test conditions were: samples conditioned at 21° C., 65% R.H; apparatus used, Textest™ Hydrostatic Head Tester, Model FX 30000; water pressure applied from below the test specimen; 5 test specimens per product; temperature of distilled water, 20° C.; increment speed of water pressure, 60 cm water/min; side of fabric tested, coated. Representative test results are listed in Table IV. 
     
       
         
               
               
             
               
               
               
             
           
               
                   
                 TABLE IV 
               
               
                   
                   
               
               
                   
                 Resistance to water penetration 
               
               
                   
                 (cm) 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 test 1 
                 76.0 
               
               
                   
                 test 2 
                 94.5 
               
               
                   
                 test 3 
                 93.5 
               
               
                   
                 test 4 
                 75.5 
               
               
                   
                 test 5 
                 92.0 
               
               
                   
                 Average 
                 86.3 
               
               
                   
                 S.D. 
                 9.7 
               
               
                   
                 % CV 
                 11.2 
               
               
                   
                   
               
             
          
         
       
     
     EXAMPLE V 
     Sample moisture barriers were tested to determine the stiffness of fabrics, based on ASTM D1388-07a. The test conditions were: samples conditioned at 23±1° C., 50±2% R.H; apparatus used, stiffness tester; Option A, Cantilever test; 5 test specimens per direction and 4 measurements per specimen. Representative test results for tests in machine direction are listed in Table V. Representative test results for tests in cross direction are listed in Table VI. 
     
       
         
               
               
               
             
               
             
               
               
               
               
             
               
             
               
               
               
               
             
           
               
                   
                 TABLE V 
               
               
                   
                   
               
               
                   
                 Bending Length 
                 Flexural rigidity 
               
               
                   
                 (mm) 
                 (μJ/m) 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                 Stiffness in Machine Direction 
               
             
          
           
               
                   
                 test 1 
                 62 
                 7.03 
               
               
                   
                 test 2 
                 73 
                 13.6 
               
               
                   
                 test 3 
                 66 
                 8.76 
               
               
                   
                 test 4 
                 69 
                 10.1 
               
               
                   
                 Average 
                 68 
                 9.9 
               
               
                   
                 S.D. 
                 5 
                 2.8 
               
               
                   
                 % CV 
                 6.9 
                 28.2 
               
             
          
           
               
                 Stiffness in Cross Direction 
               
             
          
           
               
                   
                 test 1 
                 42 
                 2.51 
               
               
                   
                 test 2 
                 42 
                 2.51 
               
               
                   
                 test 3 
                 40 
                 1.80 
               
               
                   
                 test 4 
                 41 
                 2.09 
               
               
                   
                 Average 
                 41 
                 2.23 
               
               
                   
                 S.D. 
                 1 
                 0.35 
               
               
                   
                 % CV 
                 2.3 
                 15.6 
               
               
                   
                   
               
             
          
         
       
     
     EXAMPLE VI 
     Sample moisture barriers were tested for water vapor transmission based on ASTM E96/E96M-05 Procedure B. The test conditions were: Procedure B (water method at 23° C.); relative humidity, 50%; container material, aluminum; exposed area, 63.62 cm 2 ; composition of sealant, microcrystalline wax; testing period, 3 days. Representative test results are listed in Table VII. 
     
       
         
               
               
               
               
             
               
               
               
               
               
             
           
               
                   
                 TABLE VII 
               
               
                   
                   
               
               
                   
                 Specimens 
                 Water vapor 
                   
               
               
                   
                 thickness 
                 transmission 
                 Permeance 
               
               
                   
                 (mm) 
                 (g/m 2  · 24 h) 
                 (ng/Pa/s/m 2 ) 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 test 1 
                 1.09 
                 7.22 
                 59.5 
               
               
                   
                 test 2 
                 1.22 
                 8.29 
                 68.3 
               
               
                   
                 test 3 
                 1.14 
                 8.00 
                 65.9 
               
               
                   
                 Average 
                   
                 7.84 
                 64.6 
               
               
                   
                 S.D. 
                   
                 0.55 
                 4.5 
               
               
                   
                 % CV 
                   
                 7.1 
                 7.0 
               
               
                   
                   
               
             
          
         
       
     
     Of course, the above described embodiments are intended to be illustrative only and in no way limiting. The described embodiments are susceptible to many modifications of form, arrangement of parts, details and order of operation. The invention, rather, is intended to encompass all such modification within its scope, as defined by the claims.