Patent Publication Number: US-7591110-B2

Title: Building foundation

Description:
CROSS REFERENCE TO RELATED APPLICATION 
   This application claims the benefit of U.S. application Ser. No. 60/858,035 filed on Nov. 10, 2006 and entitled, “Building Foundation.” U.S. application Ser. No. 60/858,035, including all incorporated appendices, is incorporated by reference herein in its entirety for all purposes. 

   FIELD OF THE INVENTION 
   The present invention relates generally to a building foundation construction. More particularly, the present application is directed to a building foundation that has a crawl space and that has a foundation wall without the presence of a bond beam. 
   BACKGROUND 
   Buildings, such as houses, typically have foundations made from various types. Slab foundations may be used in which anchor bolts or MSA anchors are embedded into a concrete slab and have a bottom plate attached thereto. The bottom plate is the portion of the foundation onto which vertical members such as the walls of the structure are attached. Alternative arrangements are possible in which a sill anchor is embedded in the slab and is nailed into the bottom plate in order to hold the bottom plate in place. Another foundation type commonly employed is found in the construction of vinyl sided homes. These foundations include a brick foundation wall reinforced along its length by a plurality of piers. The sill is located on top of the brick foundation wall. A third type of building foundation is found in homes made of brick. Here, a foundation wall made of concrete blocks rests behind a face brick wall that makes up the exposed, viewable side of the house. The sill is located on top of the concrete wall. 
   The foundations in brick homes generally include a bond beam that makes up the top portion of the foundation wall. The upper cells of the foundation wall define a U-shaped channel that runs the length of the foundation wall. A horizontally oriented piece of rebar is disposed in and runs the length of the U-shaped channel. Grout is poured into the U-shaped channel to complete formation of the bond beam which in turn strengthens the resulting foundation. Although capable of strengthening a building foundation, bond beams are problematic in that they increase the amount of labor and cost associated in building the resulting foundation. Additionally, the bond beam is usually inspected prior to allowing a framer to begin construction on top of the sill. Such an inspection of the bond beam increases the cost of construction and can cause delays in finishing. 
   It is also known to employ seismic straps in building foundations in order to provide strength during shaking of the house in an earthquake. A typical seismic strap is a galvanized steel member 3/16 inches thick and 2 inches wide. The seismic strap is embedded in the concrete footing of the building foundation and runs vertically through an aligned series of cells of the concrete foundation wall. The seismic strap emerges from the top of the foundation wall and is nailed into the sill. A series of seismic straps can be present along the length of the foundation wall and spaced no greater than 6 feet on center from one another and 1 foot from the corners in various designs. When used in foundations for vinyl sided homes, a pair of seismic straps are included in every pier. 
   Although suitable for their intended purpose, seismic straps are problematic in that the mason must, when building the concrete foundation wall, maneuver concrete cells around the seismic straps. Further, the seismic straps must be precisely positioned in order for the aligned series of cells to be properly disposed around the seismic straps across the entire length of the foundation wall. An error in spacing of either the seismic straps or the cells will require the mason break one or more cells in order to complete construction of the foundation wall. The use of seismic straps may therefore result in the loss of time and money and could potentially result in a foundation that is not structurally sound. Additionally, seismic straps are generally formed via a stamping process that results in sharp edges along the sides and top thereof. Sharp edges of this sort cause injury to workers in construction of the foundation wall. Further, the sharp edges have a tendency to cut string positioned along the foundation wall that is used when laying concrete block. The cost and time of construction of foundation walls thus occur. Accordingly, there remains room for variation and improvement within the art. 
   SUMMARY 
   Various features and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned from practice of the invention. 
   One aspect of an exemplary embodiment is provided in a building foundation that has a footing and a foundation wall supported by the footing. The foundation wall has a plurality of cells arranged to define aligned cell cavities at least some of which are filled in with grout. At least some of the cells of the top row of cells of the foundation wall have a cross-sectional shape that is the same as at least some of the cells of a lower row of cells of the foundation wall. A seismic strap is at least partially located in at least one set of the aligned cell cavities filled in with grout. The seismic strap is embedded in the footing. A sill is supported by the foundation wall. The seismic strap is attached to the sill. 
   Another aspect of an exemplary embodiment is found in a building foundation as immediately discussed in which two pieces of horizontally disposed rebar are located in the footing. Vertically disposed rebar is located in the set of aligned cell cavities filled in with grout in which the seismic strap is located. 
   An additional aspect of another embodiment resides in a building foundation as immediately discussed in which the seismic strap contacts the vertically disposed rebar. The vertically disposed rebar contacts one of the pieces of horizontally disposed rebar. 
   A further aspect of one exemplary embodiment exists in a building foundation that has a footing and a foundation wall supported by the footing. The foundation wall has a plurality of cells. The top row of cells does not include a bond beam. Also, the foundation wall does not include a seismic strap therein. A sill anchor is at least partially located in the foundation wall. The sill anchor is configured for attachment to a sill. 
   Another aspect of a further exemplary embodiment is found in a building foundation as immediately discussed in which the plurality of cells are arranged to define a set of aligned cell cavities. The sill anchor is at least partially located in an upper cell of the set of aligned cell cavities and is embedded in grout that fills the set of aligned cell cavities. 
   An additional aspect of another exemplary embodiment includes a building foundation as immediately discussed in which vertically disposed rebar is embedded in the footing and is located in the set of aligned cell cavities in which the sill anchor is located. The vertically disposed rebar is embedded in grout that fills the set of aligned cell cavities. 
   One aspect of another exemplary embodiment resides in a building foundation as previously mentioned in which the sill anchor has an elongated portion with a hooked end. Also, the sill anchor has a formable portion that includes a pair of ears that are capable of being formed. 
   A further aspect includes an exemplary embodiment of a building foundation that has a footing and a foundation wall supported by the footing. The foundation wall has a plurality of cells arranged to define a set of aligned cell cavities. The plurality of cells are arranged to define a top row of cells. At least some of the cells of the top row of cells have a cross-sectional shape that is the same as at least some of the cells of a lower row of cells of the foundation wall. A sill anchor is at least partially located in the set of aligned cell cavities of the foundation wall. Grout is disposed in the set of aligned cell cavities between the sill anchor and the footing. The sill anchor is configured for attachment to a sill. 
   Another aspect provides for an exemplary embodiment of a building foundation as previously discussed that further includes a vertically disposed rebar embedded in the footing and located in the set of aligned cell cavities in which the sill anchor is located. The vertically disposed rebar is embedded in grout in the set of aligned cell cavities. 
   An additional aspect resides in an exemplary embodiment as mentioned prior in which the foundation wall does not include a seismic strap therein. 
   A further aspect includes an exemplary embodiment in which the sill anchor has a hooked end and a formable portion with a pair of ears. The hooked end of the sill anchor is embedded in grout that is included in the foundation wall. The ears of the sill anchor are located outside of the foundation wall and have a plurality of apertures configured for receipt of nails for use in attaching the ears to a sill supported by the foundation wall. 
   A further aspect exists in an exemplary embodiment as described above that further includes a faced brick wall that is supported by the footing. 
   These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth more particularly in the remainder of the specification, which makes reference to the appended Figs. in which: 
       FIG. 1  is a perspective view of a portion of a building foundation that includes a seismic strap in accordance with one exemplary embodiment of the present invention. 
       FIG. 2  is a side view of the building foundation of  FIG. 1  that further includes a faced brick wall. 
       FIG. 3  is a perspective view of a portion of a building foundation that includes a sill anchor in accordance with one exemplary embodiment of the present invention. 
       FIG. 4  is a side view of the building foundation of  FIG. 1 . 
       FIG. 5  is a perspective view of a sill anchor that can be used in various exemplary embodiments of the present invention. 
       FIG. 6  is a side view of a building foundation in which a seismic strap contacts vertically disposed rebar in accordance with another exemplary embodiment of the present invention. 
   

   Repeat use of reference characters in the present specification and drawings is intended to represent the same or analogous features or elements of the invention. 
   DETAILED DESCRIPTION OF REPRESENTATIVE EMBODIMENTS 
   Reference will now be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, and not meant as a limitation of the invention. For example, features illustrated or described as part of one embodiment can be used with another embodiment to yield still a third embodiment. It is intended that the present invention include these and other modifications and variations. 
   It is to be understood that the ranges mentioned herein include all ranges located within the prescribed range. As such, all ranges mentioned herein include all sub-ranges included in the mentioned ranges. For instance, a range from 100-200 also includes ranges from 110-150, 170-190, and 153-162. Further, all limits mentioned herein include all other limits included in the mentioned limits. For instance, a limit of up to 7 also includes a limit of up to 5, up to 3, and up to 4.5. 
   The present invention provides for a building foundation  10  used in the construction of structures such as homes. The building foundation  10  may be used in the construction of brick homes in accordance with various exemplary embodiments. The building foundation  10  employs a design that eliminates the presence of a bond beam in the top row of cells  38  in the foundation wall  12  of the building foundation. Other embodiments also exist in which seismic straps  24 , commonly employed to prevent damage in earthquakes, are eliminated from the building foundation  10 . 
     FIG. 1  is a perspective view of a building foundation  10  in accordance with one exemplary embodiment of the present invention. The building foundation  10  includes a foundation wall  12  that rests on a footing  14 . Footing  14  can be a continuously solid structure or can be a fully grouted masonry or concrete structure. Two pieces of horizontal rebar  18  are present in footing  14  in order to provide reinforcing strength to the concrete or other material making up the majority of footing  14 . Although shown as employing a pair of #4 rebar  18 , it is to be understood that any number or type of rebar  18  may be used in accordance with other exemplary embodiments. Footing  14  is supported by soil  16  as shown in  FIG. 2  which can be either undisturbed natural soil or engineered fill. In accordance with one exemplary embodiment, the foundation wall  12  rests on a maximum of 24 inches of unbalanced fill. The sizing and composition of footing  14  may be as that called for in Section R403 and Table R403.1 of the 2003 International Residential Code® set forth by the International Code Council in establishing construction standards. 
   The building foundation  10  also includes a foundation wall  12 . The foundation wall  12  can be configured as that commonly known as a solid 8 inch wall. In accordance with the exemplary embodiment in  FIGS. 1 and 2 , the foundation wall  12  has a maximum height above grade of 48 inches. The foundation wall  12  can be made from a plurality of concrete cells  20  that include cavities therethrough. The cells  20  can have a length of 8 inches on one side so that the width of the resulting foundation wall  12  is 8 inches. The cells  20  can be arranged with respect to one another so that cavities between vertically adjacent upper and lower cells  20  line up with one another to form a set of aligned cell cavities  22 . Although described as being made up of a number of concrete cells  20 , it is to be understood that the foundation wall  12  can be constructed of other materials in accordance with other exemplary embodiments of the present invention. The cells  20  can be 8×8×16 inch block in accordance with one exemplary embodiment. 
   The building foundation in  FIGS. 1 and 2  includes a seismic strap  24  located in the aligned cell cavities  22 . Seismic strap  24  can be made of galvanized steel and may have a thickness of 3/16 th  of an inch and a width of 2 inches. Seismic strap  24  has a lower angled portion  26  that is embedded in the footing  14 . In certain embodiments, the lower angled portion  26  is embedded a minimum of 4 inches in footing  14 . The seismic strap  24  can be placed within 1 foot from each corner of the foundation wall  12 . The corners in this instance include both 90° corners and those that are not 90° such as those associated with bay windows. The seismic straps  24  can also be spaced a maximum of 6 feet on center from one another. Other embodiments exist in which seismic straps  24  are located every 4 feet on center from one another. 
   A piece of vertical rebar  32  is present in the same set of aligned cell cavities  22  as that which has the seismic strap  24 . The vertical rebar  32  can be connected to the seismic strap  24 . Alternatively, the vertical rebar  32  and seismic strap  24  need not be connected to one another. In a similar vein, the vertical rebar  32  and seismic strap  24  may or may not touch one another in accordance with various exemplary embodiments. The vertical rebar  32  functions so as to strengthen the foundation wall  12 . Rebar  32  has a lower angled portion  34  that is embedded in the footing  14 . In accordance with one exemplary embodiment, rebar  32  is #4 rebar and is located every 4 feet on center from one another. Further, the rebar  32  is located within 1 foot from corners including both 90° corners and those that are not 90° such as those associated with bay windows. The rebar  32  can be #4 rebar in accordance with other exemplary embodiments of the present invention. Additional seismic straps  24  are located in each of the subsequently aligned cell cavities  22  with the spaced rebar  32 . The sets of aligned cell cavities  22  that house the seismic strap  24  and vertical rebar  32  are filled with grout  36  so that a solid structure is formed. The grout  36  employed can be selected so as to be capable of withstanding a minimum of 3000 pounds per square inch. The grout  36  used in the construction of foundation wall  12  in  FIGS. 1 and 2  can be selected in order to withstand 3000 pounds per square inch. Other embodiments are possible in which the grout  36  can withstand at least a minimum of 2000 pounds per square inch. The exemplary embodiment of the foundation wall  12  shown in  FIGS. 3 and 4  can be made with grout  36  capable of withstanding 2000 pounds per square inch. 
   The vertical rebar  32  need not be in the same set of aligned cell cavities  22  as the seismic strap  24 . The aligned cell cavities will be filled with grout  36  if a seismic strap  24  or vertical rebar  32  is present. The two components can be in different sets of aligned cell cavities  22  in accordance with other exemplary embodiments. The seismic strap  32  can be located 6 feet from one another on center while the vertical rebar  32  can be located 4 feet on center from one another. 
   The building foundation  10  may be constructed in accordance with standards as those called for in section R404.1.1 of the 2003 International Residential Code® set forth by the International Code Council in establishing construction standards that deals with the construction of masonry foundation walls. Additionally or alternatively, the building foundation  10  may be made in accordance with the specifications set forth in section R404.1.4 that deal with additional requirements for foundation walls in certain seismic zones. The building foundation  10  can incorporate certain features from these standards such as tying of the vertical rebar  32  to one or both of the pieces of horizontal rebar  18  in the footing  14 . 
   The aforementioned specifications in section R404.1.1 call for a bond beam in the top row of cells that make up the foundation wall  12 . The bond beam includes a piece of horizontally oriented #4 rebar that is located in the upper 12 inches of the foundation wall  12 . The building foundation  10  presently disclosed does not have this bond beam present. In this regard, the top row of cells  38  does not have a piece of horizontal rebar therein. The top row of cells  38  may have a configuration the same as that of the bottom or any intermediate row of cells of the foundation wall  12 . As such, the cross-sectional shape of at least one of the cells  20  of the top row of cells  38  is the same as the cross-sectional shape of one or more of the cells  20  of a lower row. 
   A sill  40  rests on the top row of cells  38  of the foundation wall  12 . Vertical members, such as the walls of the structure, are built upon the sill  40 . The sill  40  includes a sill plate  42 , sometimes referred to as a mud sill, that contacts the top row of cells  38 . The sill plate  42  covers cells  20  in the top row of cells  38  that are filled with grout  36  and those that are not filled with grout  36 . The sill plate  42  can be a piece of treated lumber. Foundation walls  12  are commonly built with a sill plate  42  that is a 2×8. Sill  40  can also include a pair of sill boards  44  and  46  that rest on top of sill plate  42  and are oriented at a 90° angle thereto. Sill boards  44  and  46  may also be pieces of treated lumber. In accordance with one exemplary embodiment, sill boards  44  and  46  are 2×10s. Other exemplary embodiments exist in which sill boards  44  are 2×8s and/or 2×12s. 
   The seismic strap  24  protrudes from the top row of cells  38  and has an upper portion  28  that engages the sill  40 . The sill plate  42  can be notched if necessary in order to position the upper portion  28  against the sill board  46 . A series of apertures  30  are defined through the upper portion  28 . Nails  48  are driven through apertures  30  and into sill boards  44 ,  46  in order to attach the seismic strap  24  to the sill  40 . In certain exemplary embodiments 9 nails  48  can be driven through sill board  46  and then into sill board  44 . In this manner, the seismic strap  24  acts to hold the sill  40 , foundation wall  12  and footing  14  to one another during a seismic event. In accordance with other embodiments, the seismic strap  24  may be additionally attached to the sill plate  42 . Although described as employing a seismic strap  24 , other exemplary embodiments of the present invention are possible in which the building foundation  10  does not have a seismic strap  24 . The building foundation shown in  FIGS. 1 and 2  can be used in the construction of a brick house.  FIG. 2  shows a faced brick wall  50  located adjacent to the foundation wall  12  that makes up the exterior side of the home. 
     FIG. 6  illustrates an alternative exemplary embodiment of the building foundation  10  similar to that shown and described in relation to  FIGS. 1 and 2 . However, the building foundation  10  of  FIG. 6  differs in that the seismic strap  24  within the aligned cell cavities  22  contacts the vertically disposed rebar  32 . 
     FIGS. 3 and 4  show a building foundation  10  in accordance with another exemplary embodiment of the present invention. The building foundation  10  includes some features similar to those previously discussed with respect to the embodiment described in  FIGS. 1 and 2 . For example, the footing  14  may be a continuous concrete footing and can be constructed as per section R403 and Table R403.1 of the 2003 International Residential Code® set forth by the International Code Council. The exemplary embodiment in  FIGS. 3 and 4  can be provided with components sized and selected as those disclosed in the tables and code sections previously mentioned with respect to the exemplary embodiment in  FIGS. 1 and 2 . A pair of rebar pieces  18  can be #4 type continuous rebar with a minimum 12 inch LAP. The foundation wall  12  can include cells  20  made of 8 inch by 8 inch by 16 inch concrete block per 2003 International Residential Code® R606.5. However, it is to be understood that the blocks can be sized differently in accordance with other exemplary embodiments. The foundation wall  12  of  FIGS. 3 and 4  may have a height above grade of 48 inches. In accordance with certain exemplary embodiments, the height of the foundation wall  12  can be up to 108 inches above grade. 
   The cells  20  may be filled with 2000 psi grout  36 . A single piece of vertical rebar  32  is located in the aligned cell cavities  22 . Rebar  32  can be #4 type rebar and is located every 4 feet on center along the foundation wall  12  and may be tied to one or more pieces of the horizontal rebar  18  in the footing  14 . The height and other properties of the foundation wall  12  can be provided as those set forth in tables R404.1.1(1), R404.1.1(2), R404.1.1(3) and R404.1.1(4) of the 2003 International Residential Code® set forth by the International Code Council. 
   The building foundation  10  in  FIGS. 3 and 4  also includes a sill anchor  52  located in a cavity of a cell  20  in the top row of cells  38 . The vertical rebar  32  is present in the same cell  20  cavity as the sill anchor  52 . The vertical rebar  32  and sill anchor  52  may or may not contact one another in various embodiments. Further, these two components may or may not be attached to one another in different embodiments of the building foundation  10 . Maximum spacing of the sill anchor  52  along the length of the foundation wall  12  is 4 feet on center. In this regard, vertical rebar  32  and a sill anchor  52  may be present every 4 feet on center along the length of the foundation wall  12 . The sill anchor  52  may be provided so as to be no more than 1 foot from the corners or ends of the foundation wall  12 . The top of vertical rebar  32  can be within ½ an inch of the top of the top row of cells  38 . The vertical rebar  32  is encased within the grout  36  and thus does not protrude from the top of cells  20 . 
   In accordance with one exemplary embodiment, the sill anchor  52  can be a MAS sill plate to foundation anchor such as one provided by Simpson Manufacturing having offices at 5956 W. Las Positas Blvd., Pleasanton, Calif. 94588. In accordance with one exemplary embodiment of the present invention, the sill anchor  52  is a mud sill anchor such as that described in U.S. Pat. No. 4,413,456 entitled “Mud Sill Anchor” whose inventor is Tyrell T. Gilb. The entire contents of U.S. Pat. No. 4,413,456 are incorporated by reference herein in their entirety for all purposes. The aforementioned mud sill anchors are embedded into the slab of a slab foundation and anchor the mudsill to the slab. 
   The sill anchor  52  may be a Simpson MAS or MASB anchor placed within the cells  38  next to the vertical rebar  32  that can be #4 rebar. Sill anchors  52  can be spaced every 4 feet from center to center and may be 1 foot from the corners or ends. Pressure treated wood may be used in the construction of the sill  40  and also for an interior brace wall. The sill anchors  52  can be spaced so as not to exceed 6 feet from center to center when used on the interior brace wall. A faced brick wall  50  may be included with 8 inch Durawire for each course of block and brick ties as set forth in section R703.7 of the 2003 International Residential Code®. 
   One embodiment of the sill anchor  52  is shown in greater detail in  FIG. 5 . The sill anchor  52  has an elongated portion  58  with a hooked end  56 . The sill anchor  52  can be made of steel in accordance with one embodiment. A formable portion  60  is located on the end of elongated portion  58  opposite hooked end  56 . Formable portion  60  includes a pair of ears  54  that define a plurality of apertures  62 . Formable portion  60  can be bent or otherwise formed by a user into a desired shape. 
   Referring back to  FIGS. 3 and 4 , the sill anchor  52  is embedded in grout  36  in a cell cavity in the top row of cells  38 . The elongated portion  58  extends at an angle to the vertical rebar  32  in the cell cavity in the top row of cells  38 . The elongated portion  58  may extend at an angle from 25° to 65° to the vertical rebar  32  in accordance with various exemplary embodiments. The hooked end  56  is also embedded in the grout  36 . Formable portion  60  extends upward from and out of the top row of cells  38 . Formable portion  60  can be bent so as to be positioned proximate to the side of a sill plate  46  of sill  40 . The sill  40  and associated sill plate  42 , sill board  44  and sill board  46  can be provided and arranged in manners similar to those previously discussed with respect to the exemplary embodiments of  FIGS. 1 and 2 . It is likewise to be understood that the sill  40  in all embodiments need not have any or all the displayed components such as the sill plate  42 , sill board  44  and/or sill board  46 . Nails  48  can be driven through apertures  62  of the ears  54  of sill anchor  52  in order to attach sill anchor  52  to the sill plate  46 . The nails  48  are driven through the sill plate  46  and into sill plate  44 . In accordance with one embodiment 8 nails  48  are used to attach the sill anchor  52 . Nails  48  can also be driven into the sill plate  42  in order to attach the sill anchor  52  thereto if desired in accordance with other embodiments. Attachment to sill anchor  52  causes sill  40  to be firmly rooted to the foundation wall  12 . 
   As with the previously described exemplary embodiment, the building foundation  10  in  FIGS. 3 and 4  does not include a bond beam, or associated components such as horizontal rebar, in the top row of cells  38 . Consequently, the cells  20  making up the top row of cells  38  have the same cross-sectional shape as those making up subsequent rows of the foundation wall  12 . Unlike the exemplary embodiment shown in  FIGS. 1 and 2 , the building foundation  10  in  FIGS. 3 and 4  does not employ seismic straps  24 . 
   Although not shown in the previous figures for sake of clarity, the building foundation  10  may include horizontal joint reinforcements in each course as is commonly known in building foundation designs. The joint reinforcement can be 12 inch Durabond Wire® without wall ties. Alternatively the joint reinforcement can be 8 inch wire with corrugated wall ties within a 2 foot by 2 foot square. Such wire may be as that supplied by Durbond Products Limited having offices at 55 Underwriters Road, Scarborough, Ontario, Canada M1R 3B4. The masonry cement employed in construction of the foundation wall  12  may be Holcim® type S masonry cement manufactured by Holcim Inc., having offices at 6211 North Ann Arbor Road, Dundee, Mich., 48131. It is to be understood that this is but one type of masonry cement that can be employed and that other types are possible in accordance with other embodiments. 
   While the present invention has been described in connection with certain preferred embodiments, it is to be understood that the subject matter encompassed by way of the present invention is not to be limited to those specific embodiments. On the contrary, it is intended for the subject matter of the invention to include all alternatives, modifications and equivalents as can be included within the spirit and scope of the following claims.