Patent Publication Number: US-6901709-B2

Title: Concrete panel skirting system for manufactured homes and method for making the same

Description:
This application claims benefit of Provisional 60/332,634 filed Nov. 20, 2001. 

   BACKGROUND 
   a. Field of the Invention 
   The present invention relates generally to manufactured homes installations, and, more particularly, to a system for providing skirting around manufactured home or similar building using pre-cast concrete panels. 
   b. Related Art 
   Examples of manufactured homes include both mobile homes and prefabricated houses. As in known in the art, manufactured homes are typically installed by transporting the home in one or more pieces and then assembling the pieces at the installation site. The bottom of the structure is usually positioned a spaced distance above the ground, so as to permit airflow and provide access to the bottom of the structure. This creates a gap around the perimeter of the structure, which must be covered, both for the sake of appearance and also to prevent excessive heat loss through the bottom of the home. 
   Conventionally, the edge gap is covered with a skirting constructed of wood e.g., plywood paneling. Although common, this approach presents several serious disadvantages. For example, conventional skirting often takes 2-3 days to complete, adding significantly to the time and cost of the installation, and the lumber itself is not inexpensive. Furthermore, soil is usually backfilled against the skirting to provide added insulation and a more finished appearance, and the resulting soil contact causes the wooden skirting to rot and deteriorate over time. Still further, in the event that the building is moved from its initial installation site (which is not uncommon in the case of manufactured homes), it is virtually impossible to remove and reuse the wood skirting, so that new skirting must be purchased and installed at the new location, thereby adding significantly to the cost of the move. 
   Accordingly, there exists a need for a skirting system for manufactured homes that can be installed with a minimum of time and labor. Furthermore, there exists a need for such a skirting system that uses low cost materials. Still further, there exists a need for such a skirting system that is durable and will not rot when placed in contact with soil and moisture. Still further, there exists a need for such a skirting system that is easily removed and reinstalled if the home is moved to a new location. 
   SUMMARY OF THE INVENTION 
   The present invention has solved the problems cited above, and is a system for skirting a manufactured home or similar building with modular panels. 
   Broadly, the method comprises the steps of (a) providing a plurality of substantially flat concrete panels having a height approximately equal to a predetermined height between a rim joist of the building and an underlying ground surface, (b) placing said panel members in edge-to-edge relationship between the rim joist and the underlying ground, (c) inserting locking members between adjoining edges of the panel members, so that the first and second edges of the locking members are received in corresponding edge slots of the panel members, and (d) securing upper ends of the locking members to the rim joist, so that the locking members maintains the panel members in edge-to-edge relationship and secure the panel members to the building. 
   The step of mounting the upper ends of the locking members to the rim joist of the building may comprise driving fasteners through an upper portion of the locking member and into the overlying joist. 
   The method may further comprise the step of securing lower edges of the panel members to the underlying ground. The step of securing the lower edges of the panel members to the underlying ground may comprise providing a tie-down member that is mounted to the lower edge of each panel member, and driving a fastener through the tie-down member and into the ground. 
   The method may further comprise the step of backfilling soil against outer surfaces of the concrete panels. 
   The invention also provides a modular panel member for skirting a manufactured home or similar building. Broadly, the panel member comprises a generally flat concrete panel having first and second end edges, an upper edge for fitting against a rim hoist of the building, and a lower edge for resting on underlining ground, each of the end edges having slots formed therein for receiving a key member that is mounted to the rim joist of the building, so that the key member secures adjoining panel members in vertical, edge-to-edge relationship beneath the rim joist. 
   The panel member may further comprise a wire rod reinforcement frame embedded in the concrete. Furthermore, the panel member may comprise at least one vent frame for permitting flow of ventilating air therethrough when installed. 
   The slots in the end edges of the panel member may extend over only an upper portion of the height thereof. The end slots may be tapered for insertion of a metal flange of the key member therein. 
   The panel member may be formed with at least one recessed area for reducing the total weight of the member. The panel member may also comprise a wooden furring strip mounted atop the upper edge thereof. 
   The key member for securing the panel members to the rim joist may comprise a vertically elongate metal member having first and second edge flanges for being received in the edge slots of the panel members. The key member may further comprise a mounting flange at the upper end of the vertically elongate member, for attachment to the rim joist by fasteners. The fasteners may be driven through the mounting flange or mounted thereto. The key member may also comprise a rearwardly extending flange for maintaining spacing between adjoining end edges of the panel members. 
   The invention also provides a method for forming the concrete skirting panels. The method comprises (a) providing a mold assembly having a stationary inner bulkhead and first and second outer bulkheads that are mounted on hinges in spaced, parallel relationship to the stationary bulkhead so as to form first and second mold cavities, (b) filling the first and second mold cavities with concrete slurry, and (c) pivoting the outer bulkheads away from the inner bulkhead about the hinges so as to release the concrete panel members from the mold cavities when at least partially cured. 
   These and other features are advantages of the present invention will be apparent from a reading of the following detailed description with reference to accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an elevational, environmental view of a manufactured home having an installed concrete panel skirting system in accordance with the present invention; 
       FIG. 2  is a front, elevational view of one of the concrete panels of the skirting system of the present invention, with dotted line images showing the recessed areas that are formed in the rearward side of the panel for minimizing the weight thereof; 
       FIG. 3  is a cross sectional view of the concrete panel of  FIG. 2 , taken along line  3 — 3  in  FIG. 2 , showing the continuation of the recessed areas in the rearward side of the panel in greater detail; 
       FIG. 4  is an enlarged view of the edge portion of the panel of  FIG. 3 , in the area indicated by reference numeral  4  in  FIGS. 3 , showing the edge slot, which interfits with a metal locking key so as to secure the panels to the rim joist of the building; 
       FIG. 5  is second cross sectional view of the concrete skirting panel of  FIG. 2 , taken along  5 — 5  in  FIG. 2 , showing the profile of the panel in greater detail and also the furring strip which extends along the upper edge of the panel attachment of a trim board on other covering; 
       FIG. 6  is an enlarged, partial cross sectional view of the panel in the area indicated by reference numeral  6  in  FIG. 5 , showing the relative thickness and the profiles at the edges of the recessed areas of the panel; 
       FIG. 7  is a front, elevational view of another concrete skirting corner panel in accordance with the present invention, for connecting the skirting panels at the corner of the building; 
       FIG. 8  is the top, plan view of the concrete corner panel of  FIG. 7 , showing the right angle corner segments thereof in greater detail; 
       FIG. 9  is an enlarged, partial view of the corner panel of  FIG. 8 , in the area indicated by reference numeral  9  in  FIG. 8 , showing the contours at the inside corner of the panel in greater detail; 
       FIG. 10  is a front, elevational view of the metal locking key that inter-connects adjoining panels in the assembly and secures them to the overlying rim joist of the building; 
       FIG. 11  is a side, elevational view of the locking key of  FIG. 10 , showing the forwardly projecting flange portion thereof in greater detail; 
       FIG. 12  is a top, plan view of the metal locking key of  FIGS. 10-11 , showing the upper mounting plate thereof in greater detail; 
       FIG. 13  is a bottom, plan of the metal locking key of  FIGS. 10-11  showing the configuration of the laterally projecting flange portion thereof that interfit with the edge slots of adjoining concrete panels; 
       FIG. 14  is a rear, elevational view of the adjoining edges of first and second concrete skirting panels installed as shown in  FIG. 1 , showing the manner in which the locking key of  FIGS. 10-13  interfits with the edge slots and is secured to the rim joist of the building using nails or other fasteners; 
       FIG. 15  is a front, elevational view of a mold assembly used to manufacture the concrete skirting panels of  FIGS. 2-6 , with the mold assembly being made of hinged steel panels; 
       FIG. 16  is a plan view of the open top of the mold assembly of  FIG. 15 , showing the first and second cavities that are provided for casting two skirting panels simultaneously; 
       FIG. 17  is a cross sectional view, taken along line  17 — 17  in  FIG. 15 , showing the relationship of the two mold cavities and the mold bulkheads in greater detail; 
       FIG. 18  is an end view of the mold assembly of  FIGS. 15-17 , showing the parallel relationship of the mold bulkheads and also the cylindrical supports that are mounted at each end of the assembly to permit convenient inversion thereof for casting and removal of the panels; 
       FIG. 19  is an enlarged, partial view of the end of one of the cylindrical supports, showing the manner in which this is supported pivoting relationship in a chain link or similar structure; 
       FIG. 20  is a front, elevational view of the inner bulkhead of the mold assembly of  FIGS. 15-17 , showing the raised panels that form the recessed areas in the concrete skirting panels and also the pipe segments that are mounted to the ends of the inner bulkhead to form the pivoting support as shown in  FIGS. 18-19 ; 
       FIG. 21  is a top, plan view of the inner bulkhead of  FIG. 20 , showing the raised mold panels in greater detail; 
       FIG. 22  is an end, cross sectional view of the mold assembly of  FIGS. 15-17 , showing the relationship of the inner and outer bulkheads in greater detail; 
       FIG. 23  is an enlarged, partial view of the lower end of the mold assembly of  FIG. 22 , showing the hinges that interconnect the mold bulkheads so as to permit the outer bulkheads to be pivoted away from the inner bulkhead for removal of the concrete skirting panels when cured; 
       FIG. 24  is front, elevational view of a bulkhead key mold that is placed in the ends of the mold cavities in the assembly of  FIGS. 15-17 , so as to form the slots in the ends of the concrete skirting panels that interfit with locking key of  FIGS. 10-11  when installed; 
       FIG. 25  is a side, elevational view of the key mold of  FIG. 24 , showing the forwardly projecting flange portion thereof in greater detail; and 
       FIG. 26  is a top, plan of the key mold of  FIGS. 24-25 , showing the side edges thereof that engage the inner and outer bulkheads of the assembly to seal the ends of the mold cavities during casting of the concrete skirting panels. 
   

   DETAILED DESCRIPTION 
   a. Overview 
   As can be seen in  FIG. 1  the present invention provides a modular skirting system  10  which includes a series of pre-cast concrete panels  12 . The panels are installed in an end-to-end relationship around the base of a manufactured home  14  or other building. The upper edges of the skirting panels are attached to the wooden rim joist  16  that extends about the perimeter of the structure and the lower edges rest on the underlying ground. As will be described in greater detail below, the adjoining end edges of the panels are provided with vertically extending slots which receive and engage cooperating flanges on downwardly extending metal key members that are nailed or otherwise mounted to the rim joist. 
   Because of their modular configuration and also because of the innerfitting edge structure, the panels  12  can be installed to complete the skirting within a matter of hours, as compared to days when used conventional wood skirting. Furthermore, in most instances, the concrete panels and associated hardware will also be less expensive than wood construction. Still further, the concrete is not affected by rot or other deterioration when soil  18  is back-filled against it, as is shown in FIG.  1 . 
   It will be understood that the term “manufactured home” as used herein includes all forms of buildings that are premanufactured and then transported to an installation site, whether intended as a residence or for other purposes. Furthermore, the term “concrete” as used herein includes all suitable forms of cementitious materials, whether containing aggregate material or consisting of essentially “neat” cement. 
   b. Modular Panels 
     FIG. 2  shows a cast concrete skirting panel  12  in accordance with a preferred embodiment of the present invention. Although it has been found that this configuration provides a low cost and highly effective panel for most installations, certain illustrated features or aspects may vary in other embodiments; for example, not all embodiments may include the ventilation screen which is shown in FIG.  2 . 
   In the embodiment which is shown in  FIG. 2 , the panel assembly  12  includes a generally flat, rectangular concrete main casting  20  having a height suitable for spanning the gap between the ground and the rim joist of the manufactured home. The front surface of the panel casting is preferably flat and may be provided with decorative texturing or other surface ornamentation, while a series of recesses  24   a ,  24   b ,  26  are formed in its rearward surface to lighten the panel and minimize the amount of concrete required. A full thickness concrete border  30  extends around the recesses and along the perimeter of the panel casting, and additional full thickness ribs or columns  32   a ,  32   b  extend vertically through the middle portion of the panel so as to provide the necessary overall strength and rigidity. 
   A screen unit  34  (e.g., a molded plastic frame and screen) is mounted in the upper portion of the panel casting, above the central recessed  26 . Other openings, such as flood vents, may also be included. The upper edge of the screen unit and the upper edge of the panel casting lie flush with one another, and are overlain by a wooden furring strip  36  (e.g., a length of 2×2 lumber) that receives screws or other fasteners for subsequently installed trim. The furring strip is mounted to a wire rod reinforcement frame that is imbedded in the concrete, as will be described in greater detail below. First and second wire lifting loops  40   a ,  40   b  may also be provided that extend above the furring strip, with their lower ends  42   a ,  42   b  being anchored in the underlining concrete matrix. 
   First and second slots  44   a ,  44   b  are formed in the vertical end edges  46   a ,  46   b  of the panel casting for engaging the metal locking keys of the assembly. As can be seen in  FIG. 4  each of the slots is defined by first and second sidewalls  48   a ,  48   b  that taper inwardly and a transverse bottom wall  50  at a predetermined depth “d”. As will be described in greater detail below, the edge slots are thus configured to cooperate with laterally extending flanges of the locking keys in order to secure adjoining panels in end-to-end relationship. As will be described below, the rearward edges of the slots are provided with cutaway portions  51  that accommodate the rearward flanges of the locking keys. 
   Metal tie-down straps  52   a-c  are in turn mounted along the lower edge of the panel casting, with their upper ends  54   a-c  again being embedded in the concrete matrix. Openings  56  are provided in the protruding ends of the metal tie-down straps for securing the lower edge of the panel to the ground during installation, as will be described in greater detail below. Metal tie-down straps suitable for use in the panel assembly  12  are available under the trademark “Simpson Strong Tie”. 
     FIGS. 5-6  show the arrangement of the recessed areas of the casting in greater detail. As can be seen in  FIG. 6 , the full thickness border portion  30  of the casting has a relatively greater thickness “t 1 ” and the recessed areas have a second, lesser thickness “t 2 ”. The transition areas  60  between the full thickness and partial thickness areas are preferably sloped at an angle of about 45° so as to reduce concentration of stresses and increase strength and durability of the panel casting. 
   Reinforcement rods or wire  58  are preferably embedded within the full thickness border as well as within the vertical columns or ribs  32   a ,  32   b  (see FIG.  3 ). As is shown by dotted line image  62  in  FIG. 2 , the reinforcement rod (e.g., steel rebar) is preferably formed into a framework that follows the full thickness portions of the casting, including the full thickness header  64  that extends beneath the vent frame  34 . The metal rebar is bent and/or welded at the corners, and is welded to the central frame for the vent unit, which is suitably formed of bent and/or welded steel channel material. Additional reinforcement structures may also be embedded in the border at the lower ends of the vertical ribs  32   a ,  32   b  for added strength and rigidity, and reinforcing mesh  65  may be added in the panel end slots as shown in FIGS. 
   Example dimensions for the panel assembly and casting that are shown in  FIGS. 2-5  are set forth in the following Table A: 
   
     
       
         
             
             
             
             
           
             
                 
               TABLE A 
             
             
                 
                 
             
           
          
             
                 
               Overall Length 
               72 
               inches 
             
             
                 
               Overall Height 
               28 
               inches 
             
             
                 
               Thickness of Border and Ribs 
               1½ 
               inches 
             
             
                 
               (t 1 ) 
             
             
                 
               Thickness of recessed areas 
               1 
               inch 
             
             
                 
               (t 2 ) 
             
             
                 
               Width of Lower Border 
               4 
               inches 
             
             
                 
               Width of Upper Border 
               3 
               inches 
             
             
                 
               Widths of Vertical Borders 
               4 
               inches 
             
             
                 
               and Ribs 
             
          
         
         
             
             
             
          
             
                 
               Vent Frame (“C” channel) 
               1½ inch × ½ inch × ⅛ inch 
             
          
         
         
             
             
             
             
          
             
                 
               Vertical length of Edge Slot 
               10½ 
               inches 
             
             
                 
               Depth of Edge Slot Depth (d) 
               ¾ 
               inch 
             
          
         
         
             
             
             
          
             
                 
               Edge Slot taper 
               ⅜ inch to ¼ inch 
             
          
         
         
             
             
             
             
          
             
                 
               Diameter of Steel 
               ⅜ 
               inch 
             
             
                 
               Reinforcement Rod 
             
             
                 
                 
             
          
         
       
     
   
   It is to be understood that the foregoing dimensions are exemplary of only one preferred embodiment of the present invention, and that the dimensions may vary depending on design factors and other considerations. For example, the panels may be constructed to have any suitable length, and the height may also vary depending on size of the gap between the building and the ground on the intended height of the skirting. 
   In addition to the flat panels described above, angled corner panels are provided for use at the corners of the manufactured home or the building. For example,  FIGS. 7-9  show a right-angle corner panel for use at a square corner, however, it will be understood that corner panels may be provided having any suitable angle. 
   As can be seen in  FIGS. 7-8 , the corner panel  70  includes first and second cast generally planar panel sections  72   a ,  72   b  that meet at a corner joint  74 . The panel sections may have any suitable length and height, and preferably have a height that corresponds to the height of the main panel assemblies. Likewise, the vertical edges  76   a ,  76   b  of the corner assembly include edge slots  78   a ,  78   b  that match the corresponding edge slots of the main panels, for receiving the locking keys in the manner described below. 
   As can be seen in  FIG. 9 , the corner portion  74  is provided with internal gusseting  80  that extends at an angle θ 2  of about 45° to the inside surfaces of the panel sections, so as to increase the strength of the assembly and again reduce stress concentrations. A wooden furring strip (not shown) is preferably mounted atop the corner panel assembly, in the same manner as the skirting panel assemblies described above. 
   Exemplary dimensions for the corner panel assembly shown in  FIGS. 7-9  are set forth in the following Table B: 
   
     
       
         
             
             
             
             
           
             
                 
               TABLE B 
             
             
                 
                 
             
           
          
             
                 
               Panel Height 
               28 
               inches 
             
             
                 
               Panel Width (w) 
               24 
               inches 
             
             
                 
               Panel Thickness (t 3 ) 
               1½ 
               inches 
             
             
                 
               Inside gusset angle 
               45 
             
             
                 
               (θ 2 ) 
             
             
                 
               Inside gusset depth 
               I 
               inch 
             
             
                 
               (V 1 , V 2 ) 
             
             
                 
                 
             
          
         
       
     
   
   Again, it will be understood that the above dimensions are exemplary only, and may vary in other embodiments depending on a variety of design factors. Also, it will be understood that the corner panel assembly may include embedded reinforcement rod or wire in a manner similar described above. 
   c. Panel Locking Key 
     FIGS. 10-13  show one of the panel metal locking keys  82  that interconnect adjoining panels in the skirting assembly when installed as shown in FIG.  1 . 
   As can be seen, the principal component of the locking key is a vertically extending metal (e.g., steel) “T” bar  84 , having a rearwardly projecting center flange  86  and laterally extending edge flanges  88   a ,  88   b . The overall length of the “T” bar is equal to or less than the vertical length of the corresponding edge slots  44   a ,  44   b  in the concrete skirting panels. 
   A generally flat mounting plate  90  is mounted (e.g., welded) to the upper end of the “T” bar  84  so as to extend perpendicular to the long axis of the bar. A plurality of bores  92  (see  FIGS. 12-13 ) extend upwardly through the mounting plate, so as to permit a plurality of nails  94  or similar fasteners to be driven upwardly therethrough, as shown in  FIGS. 10-11 . 
   In some embodiments, the fasteners may be welded to or formed as a part of the mounting plate so as to expedite installation. Furthermore, the mounting plate may have an upwardly extending outer flange portion (not shown) to allow the fasteners to be driven into the rim joist from the front rather than upwardly in installations where this is required, such as where the rim joist is underlain by a steel beam along the edge of the building. 
   Exemplary dimensions for the panel locking key shown in FIGS.  10 — 13  are set forth in the following Table C: 
   
     
       
         
             
             
             
             
           
             
                 
               TABLE C 
             
             
                 
                 
             
           
          
             
                 
               Overall Height of T bar 
               14 
               inches 
             
             
                 
               (h 1 ) 
             
             
                 
               Width of Edge Flanges 
               ⅝ 
               inches 
             
             
                 
               Width of Central Flanges 
               1½ 
               inches 
             
             
                 
               Length of Mounting Plate (l) 
               4 
               inches 
             
             
                 
               Width of Mounting Plate (w 1 ) 
               1½ 
               inches 
             
             
                 
                 
             
          
         
       
     
   
   Again, it will be understood that the above dimensions may vary from one embodiment to the next depending on design factors. 
   d. Installation 
   To install the skirting assembly, one or more locking keys  82  are first mounted at the edge of the manufactured home or other building, by placing the mounting flange against the bottom of the wooden rim joist  16  and driving nails  94  upwardly through bores  92 ; depending the assembly sequence the nails may be installed on the one side or other of the mounting plate, rather than being driven through all four of the openings as shown in FIG.  14 . 
   The panels  12  are then placed on either side of the locking key in end-to-end relationship, so that the edge flanges of the locking key are received in interfitting engagement with the edge slots  44   a ,  44   b  of the panels and so that the vertical edges of the skirting panels butt up against and are spaced apart by the central flange  86 . As this is done, the tapered edge slots permit comparatively easy initial insertion of the edge flanges on the key, and then establish a tight, stable interfit as the flange is driven home towards the comparatively narrow base of the slot; however, the key can easily be withdrawn without damaging the slot or panel in the event that the skirting is removed for subsequent installation at another site. The center flange, in turn, prevents the edge flanges from being driven too deeply into the slots and also serves to keep the edges of the concrete panels spaced just slightly apart, thus presenting an even, finished appearance and also preventing chipping or other damage to the edges of the panels. The cutaway edges  51  at the backs of the slots accommodate most of the thickness of the rearward flange so that the spacing between the edges is very small at the front of the panels, leaving only a very small gap that is quickly filled with caulk to seal the skirting and prevent a neat, virtually seamless appearance. 
   The key members are suitably formed of steel, however, it will be understood that in some embodiments high-strength molded plastic or other suitable materials may be used. It will also be understood that the rearwardly projecting center flanges may not be present in all embodiments. 
   As a next step in the installation, the anchor straps (see  FIG. 2 ) are staked to the ground or otherwise secured in order to hold the lower edges of the panels in place. A trim board (not shown) is then nailed to the furring strips  36  to cover the joint between the panels and the rim joist  16 . Corner panel assemblies (see  FIGS. 7-9 ) are installed at the corners of the building as necessary, and the installation is completed by backfilling soil against the outer faces of the panels, if desired. 
   The skirting assembly of the present invention can thus be installed in a matter of hours rather than days, using inexpensive standardized components. The concrete panels are impervious to rot and other deterioration from ground contact and will therefore will last essentially the full lifetime of the manufactured home or other building. Moreover, the skirting assembly is easily removed and installed at a new location should the home or building be moved, using the same installation steps described above. 
   e. Casting Process 
     FIGS. 15-25  illustrate the molds and other components for casting the concrete panel members used in the skirting assemblies of the present invention. These molds and components facilitate the rapid and economical manufacture of the panel assemblies, although it will be understood other molding equipment and processes may be used to construct panel assemblies that fall within the scope of the invention. 
   As can be seen in  FIGS. 15-17 , a preferred mold assembly  100  includes a pair of rectangular outer bulkheads  102   a ,  102   b  and a central bulkhead  104  that cooperate to define first and second mold cavities  106   a ,  106   b . As will be described in greater detail below, the first and second mold cavities permit the concrete skirting panels to be cast in pairs simultaneously.  FIG. 17  shows the bottom of the mold assembly opened to reveal the internal bulkhead and mold chambers, however, it will be understood that the bottom of the assembly is normally closed and secured together by hinge structures  110   a - 110   d . The upper edges of the bulkheads, in turn, are secured together during casting by a series of pivoting wing bolts  112   a - 112   d . A secondary mold cavity  114  is also provided in the upper portion of the assembly for insertion of the vent frame  34 . 
   As can be seen in  FIGS. 20-21 , the inner bulkhead  104  includes a planar central panel  116  having raised areas  120   a ,  120 ′,  120   b ,  120   b ′ and  122 ,  122 ′ formed on opposite sides, which shape the recessed areas of the concrete panels during the molding process. A plurality of hooks  124  are also mounted on opposite surfaces of the central panel  116  for supporting wire rod enforcement frames so that these become embedded in the castings. First and second pipe stubs  126   a ,  126   b  are mounted on either end of the center bulkhead along a common horizontal axis  128 , and first and second pipe rings  130   a ,  130   b  are mounted to the bottom of the mold assembly to form a second horizontal axis  132 . 
     FIGS. 22-23  show the hinge structures  110  in greater detail. As can be seen, each of the hinge structures includes first and second hinges  134   a ,  134   b  having a stationary plate member  136  and a pivoting plate member  138  that is joined to the stationary plate member by a hinge pin  140 . The two stationary plate members are welded along opposite sides of the lower surface of the bottom dam  142  at the mold so that the pivoting plate members flatly abut the outer edges  144   a ,  144   b  of the dam when extending in a vertical direction, i.e., when extending perpendicular to the stationary plate members  136 . The bottom dam  142  is in turn welded to the lower edge of the center bulkhead  104  so as to enclose the lower ends of the two mold cavities  106   a ,  106   b.    
   As can be seen with further reference to  FIG. 23 , the pivoting plate members  138  of the hinges  134   a ,  134   b  are welded to the outer faces of the outer mold bulkheads  102   a ,  102   b . The lower edges  146   a ,  146   b  of the outer bulkheads are positioned a spaced distance above the bases of the pivoting plate members  138  so as to flatly abut the upper surface of the bottom dam  142  when in the vertical, closed position as shown in  FIG. 23 , so as to form an effective seal for preventing escape of concrete during casting. Then, following curing of the concrete the latches  112  are released and the hinges allow the two outer bulkheads to pivot outwardly for removal of the cast panels, in the direction indicated by arrows  148 . 
   The final enclosures for the mold cavities  106   a ,  106   b  are formed by the end dams  150  that are shown in  FIGS. 24-26 . The end dams are mounted in pairs in each end of the mold assembly, one at the end of each mold cavity. As can be seen, each of the end dams includes an elongate plate  152  that spans the gap between the inner and outer bulkheads and serves to block the end of the mold cavity so as to prevent the escape of uncured concrete slurry. A blade or flange portion  154  formed at one end that projects inwardly towards the associated mold cavity. The blade portions serve to form the end slots in the panel castings (see  FIGS. 2-4 ) and are therefore sized with corresponding dimensions and contours. In that there is one end dam  150  for each end of the two mold cavities  106   a ,  106   b , the mold assembly  100  includes four end dams in all. As can be seen in  FIG. 26 , the end dams are suitably constructed by welding lengths of steel T-bar  156  back to back against steel channel  158 , thereby providing the end dams with sufficient rigidity and also forming comparatively wide edge surfaces for forming effective seals against the adjoining surfaces of the inner and outer bulkheads. 
   Casting of the skirting panels using the mold assembly  100  is accomplished is as follows. Firstly, the wire rod reinforcement frame is placed on the support hangers  124  on each side of the central bulkhead, as indicated by dotted line image  160  in  FIG. 20 , with the furring strip being mounted along the upper edge of the frame. The outer bulkheads  102   a ,  102   b  are then pivoted about hinges  110  to their vertical orientations, parallel to the internal bulkhead  104 . The end dams  150  are fitted between the inner and outer bulkheads at the end of each mold cavity, and are held against outward displacement by shoulders  162  on the inner ends of the pipe stubs  126   a ,  126   b  (see FIG.  20 ). The pivoting wing bolts  112  are then placed over the tops of the bulkheads, so that the depending lugs  164  thereof hold the upper edges of the bulkheads together in slight compression, so as to secure the mold assembly in its closed, sealed configuration. A vent grate  34  (see  FIG. 2 ) or other fitting may also be inserted between the inner and outer bulkheads so as to be held in place by the assembly, or a removable wooden block may be placed in this area to keep it clear of concrete for subsequent installation of the vent frame. Where additional openings are desired, these can be formed by placing foam knock-out pieces at the desired locations in the mold cavities, so that the foam pieces can subsequently be removed to form the openings. 
   The closed assembly is suspended by chain links  166  or by stationary yokes or other supports that are support pipe stubs  126   a ,  126   b  in rotating engagement therewith; as this is done, toggle pins or similar fasteners are inserted through openings  168  (see  FIG. 21 ) so as to prevent the links or other supports from slipping off the stubs. The closed assembly is then inverted so that the furring strip forms a removable lower dam and the mold cavities are filled with cement or concrete slurry through the open upper ends (see FIG.  16 ). The ends of the tie down straps are then embedded in the exposed slurry. 
   After the cement/concrete reaches an at least partially cured state, the mold assembly is again inverted by rotating the pipe stubs  126   a ,  126   b  within their supporting links or yokes. The wing bolts  112  are released and the outer bulkheads  102   a ,  102   b  are then pivoted outwardly using the hinge assemblies  110  (see arrows  148  in FIG.  23 ), with the pivoting wing bolts acting as stands to support the bulkheads horizontally above the floor. The now rigid skirting panels are pressure-washed to expose the aggregate surface, if desired, and then removed for curing. Finally, the end dams  150  are pulled away to expose the finished end slots  44   a ,  44   b.    
   After removing the panels the mold assembly is cleaned with a hose when the bulkheads are in their open positions. The bulkheads are then coated with a release lubricant and pivoted closed, and the steps described above are repeated. In this manner, the skirting panels  12  are manufactured in a rapid and highly economical manner. 
   It is to be recognized that various alterations, modifications, and/or additions may be introduced into the constructions and arrangements of parts described above without departing from the spirit or ambit of the present invention as defined by the appended claims.