Patent Publication Number: US-10316525-B1

Title: System and method for mounting wall panels to a wall

Description:
REFERENCE TO RELATED APPLICATION 
     The present application is a continuation-in-part of U.S. patent application Ser. No. 15/067,955, filed Mar. 11, 2016 and entitled SYSTEM AND METHOD FOR MOUNTING WALL PANELS SECURED TO A WALL, which in turn, is a continuation-in-part of U.S. patent application Ser. No. 15/047,024, filed Feb. 18, 2016 and entitled THERMAL BREAK SYSTEM FOR WALL PANELS SECURED TO AN EXISTING WALL, the entire disclosures of which are incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates generally to a wall system, and more particularly, to a system for easily mounting wall panels over an existing wall. 
     In order to enhance the look of a wall structure, it is known to secure decorative wall panels to the wall structure. However, the securement of wall panels to the wall structure is generally a long and tedious job since it entails using fastening devices such as nails and/or screws to secure the walls panels directly to the wall structure. In addition, the fastening devices are exposed, which can provide an unsightly appearance. 
     A system that overcomes these problems is disclosed in U.S. Pat. Nos. 8,833,015, 8,739,483, 8,925,271 and 8,966,849; and pending U.S. patent application Ser. Nos. 14/044,606, 14/256,384, 14/641,097 and 14/667,297 to the same inventor herein, the entire disclosures of which are incorporated herein by reference. In these patents, each wall panel includes a main panel section and at least two bent end sections bent at a right angle in the same direction, at edges of the main panel section. Each bent end section includes a cut-out section or recess at an inner surface thereof. A fastening extrusion is secured to an existing wall for receiving the bent end sections. The fastening extrusion includes a base section and flexible and resilient bent end securing walls extending outwardly therefrom. Each bent end securing wall includes a projection on an outer surface thereof. When the bent end sections are forced in a direction toward the existing wall, the bent end sections force the respective bent end securing walls to bias away until the projections are in line with the cut-out sections or recesses, whereupon the bent end securing walls snap back to their original position in which the projections are engaged in the cut-out sections or recesses. 
     However, the above system utilizes bent end sections at the edges of the main panel section. This increases the material that must be used, and makes the construction more complicated. 
     It would therefore be desirable to provide wall panels which do not require the bent end sections, but which can easily be installed over an existing wall. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide a system and method for easily mounting wall panels over an existing wall that overcomes the aforementioned problems. 
     It is another object of the present invention to provide a system and method for easily mounting wall panels over an existing wall, which utilizes a simple sliding action for assembling the wall panels. 
     It is still another object of the present invention to provide a system and method for easily mounting wall panels over an existing wall which provides support at an intermediate position of the wall panels where the sliding action occurs. 
     It is yet another object of the present invention to provide a system and method for easily mounting wall panels over an existing wall which easily captures and restrains ends of the wall panels. 
     It is a further object of the present invention to provide a system and method for easily mounting wall panels over an existing wall which allows for thermal expansion of the wall panels. 
     In accordance with an aspect of the present invention, a system for mounting wall panels to an existing wall, includes a plurality of fastening extrusions. Each fastening extrusion includes a base section adapted to be secured to the existing wall, at least one retaining wall extending at an angle from the base section, and a holding member on each retaining wall for holding one end of a wall panel to a respective the fastening extrusion; and wherein at least some adjacent retaining walls have different heights from each other so as to impart a three-dimensional appearance to the wall panels mounted to the existing wall. 
     Each fastening extrusion includes two spaced apart retaining walls having different heights from each other so as to secure two adjacent wall panels to the existing wall at different heights from each other in order to impart a three-dimensional appearance. Alternatively, two retaining walls associated with opposite sides of the same wall panel have different heights so as to mount the wall panel in an inclined manner on the existing wall. 
     There are also a plurality of intermediary supports for supporting the wall panels at a position between side edges of the wall panels. Each intermediary support includes an intermediary support base, two spacing walls which secure the intermediary support base to the existing wall, with a spacing between the existing wall and the intermediary support base plate, with the two spacing walls having different heights corresponding to the different heights of the two retaining walls, and a sliding member adapted to be slidably connected with the base, such that one the wall panel is adapted to be secured to the sliding member for sliding movement with the sliding member relative to the intermediary support base. 
     In one embodiment, the two spacing walls form part of a U-channel furring having lower ends thereof connected to the existing wall and further including a connection wall which connects upper ends of the two spacing walls together, with the intermediary support base mounted on the connection wall. 
     In another embodiment, the two spacing walls form part of a U-channel furring having lower ends thereof connected to the existing wall and wherein the intermediary support base connects upper ends of the two spacing walls together. 
     In accordance with another aspect of the present invention, there are a plurality of intermediary supports for supporting the wall panels at a position between side edges of the wall panels. Each intermediary support includes an intermediary support base adapted to be secured to the existing wall; a sliding member adapted to be slidably connected with the base; and a securement arrangement for securing the sliding member to a wall panel. The securement arrangement includes either an adhesive member secured between the sliding member and the wall panel, or at least one projection extending from the sliding member or the wall panel, and at least one groove in the other of the sliding member and the wall panel for receiving the at least one projection, each groove having a shape complementary to each respective projection received therein. 
     Preferably, each projection has a shape in cross-section selected from the group consisting of a trapezoid, diverging planar walls, a T-shape, and a bulbous shape. 
     There is further a thermally insulating spacer block positioned between the sliding member and the base. 
     The intermediary support base includes a base plate adapted to be secured to the existing wall, a first retaining wall connected with a first side of the base plate, and a second retaining wall connected with a second opposite side of the base plate. The sliding member includes an inverted U-shaped central member dimensioned to fit between the first and second retaining walls, a first wing member at a first side of the central member for engagement within the first retaining wall, and a second wing member at a second opposite side of the central member for engagement within the second retaining wall; and wherein the thermally insulating spacer block is positioned between the inverted U-shaped central member of the sliding member and the base. 
     In another embodiment, there is a stiffener element which fixes the distance between adjacent support bases and which provides further support for wall panels positioned thereon. Each stiffener element includes a stiffener plate; first and second separation walls extending from the underside of stiffener plate and against which adjacent intermediary support bases abut in order to fix the distance between adjacent support bases; and first and second limit walls at a center portion thereof against which ends of adjacent wall panels are adapted to abut when seated on the stiffener plate. 
     In a further embodiment, the intermediary support base includes: a base section adapted to be secured to the existing wall either directly or via a furring member, and a generally L-shaped retaining wall extends outwardly from the base section and defining a gap between the base section and the generally L-shaped retaining wall. The sliding member is formed by a generally U-shaped member formed by two parallel, spaced apart walls connected by a connecting wall, with one of the spaced apart walls adapted to slide and be captured within the gap to secure the sliding member to the intermediary support base; and a securement arrangement is connected with the other spaced apart wall of the sliding member for securing the sliding member to a wall panel. 
     The securement arrangement includes one of the following: an adhesive member secured between the sliding member and the wall panel, at least one projection extending from the sliding member or the wall panel, and at least one groove in the other of the sliding member and the wall panel for receiving the at least one projection, each groove having a shape complementary to each respective projection received therein, and screws for securing the sliding member to the wall panel. Each projection has a shape in cross-section selected from the group consisting of a trapezoid, diverging planar walls, a T-shape, and a bulbous shape. 
     In accordance with still another embodiment of the present invention, there is provided a thermal break system for securing wall panels to an existing wall, in order to mount the wall panels in covering relation to the existing wall. The thermal break system includes a furring member connected between the existing wall and the wall panels. Each furring member includes at least one first foot wall adapted to be connected to the existing wall, at least one spacing wall having one end connected to the at least one first foot wall and extending in a direction transverse to the at least one first foot wall and the existing wall, with the at least one foot wall extending outwardly to one side of the at least one spacing wall, and a connection wall connected to an opposite end of the at least one spacing wall and extending in a direction transverse to the at least one spacing wall for connection either directly to adjacent wall panels, or indirectly to adjacent wall panels through at least one intermediary member. The connection wall includes a first section extending to the one side of the at least one at least one spacing wall. A first thermal insulation cover is positioned around the at least one foot wall; and a second thermal insulation cover is positioned around the first section of the connection wall. 
     In accordance with yet another embodiment of the present invention, a system for mounting wall panels to an existing wall, includes plurality of fastening extrusions. Each fastening extrusion includes an extrusion base section adapted to be secured to the existing wall, at least one retaining wall extending at an angle from the base section, a holding member on each retaining wall, and a bent wall in the extrusion base section which is bent toward the holding member to form a gap therebetween to receive one side edge of one wall panel. A thin walled thermal insulation cover is positioned in the gap for receiving the one side of the one wall panel. 
     The thin walled thermal insulation cover includes an inner surface in facing relation to an end edge at the one side of the one wall panel, with an elongated bead formed at the inner surface and against which the end edge of the one wall panel abuts to allow for thermal expansion. 
     In accordance with a further aspect of the present invention, a system for mounting wall panels to an existing wall, includes a plurality of fastening extrusions. Each fastening extrusion includes an extrusion base section adapted to be secured to the existing wall, at least one retaining wall extending at an angle from the base section, a holding member on each retaining wall, and a bent wall in the extrusion base section which is bent toward the holding member to form a gap therebetween to receive one side edge of one wall panel. A thermal insulation cover is positioned around the extrusion base section to an outside of each bent wall. 
     In accordance with a still further aspect of the present invention, a system for mounting wall panels to an existing wall, includes a plurality of fastening extrusions. Each fastening extrusion includes an extrusion base section adapted to be secured to the existing wall, two parallel, spaced apart retaining walls extending at an angle from the base section, an outwardly extending holding wall on each retaining wall, and a bent wall in the extrusion base section to an outside of each retaining wall and which is bent toward each holding wall to form a gap therebetween to receive one side edge of one wall panel. A closure member is secured to the fastening extrusion in covering relation to the holding walls, the retaining walls and a space between the retaining walls. The closure member includes a center section which covers the space between the retaining walls, L-shaped cover walls extending from the center section and which cover the holding walls, two parallel, spaced apart walls extending from an underside of the center section, and first tabs formed at free ends of the spaced apart walls. A spacer block is mounted on the extrusion base between the retaining walls and includes two outwardly extending spaced apart side walls having a catch at a free end of each side wall for engaging with the tabs to lock closure member in position. 
     Each retaining wall includes a recess on an inwardly facing surface thereof adjacent the tabs and catches, to permit one of the tabs and catches to be biased into a respective recess during assembly of a the closure member, whereupon after insertion of the closure member, the one of the tabs and catches springs back to its original position so that each tab is captured by a respective catch. 
     In accordance with a yet further aspect of the present invention, a system for mounting wall panels to an existing wall, includes a plurality of fastening extrusions. Each fastening extrusion includes an extrusion base section adapted to be secured to the existing wall, two parallel, spaced apart retaining walls extending at an angle from the base section, each retaining wall including a recess on an inwardly facing surface thereof, an outwardly extending holding wall on each retaining wall, and a bent wall in the extrusion base section to an outside of each retaining wall and which is bent toward each holding wall to form a gap therebetween to receive one side edge of one wall panel. A closure member is secured to the fastening extrusion in covering relation to the holding walls, the retaining walls and a space between the retaining walls, the closure member including a center section which covers the space between the retaining walls, L-shaped cover walls extending from the center section and which cover the holding walls, two parallel, spaced apart walls extending from an underside of the center section, and first spring tabs formed at free ends of the spaced apart walls for engagement within the recesses when the closure member is assembled with each fastening extrusion. 
     In accordance with another aspect of the present invention, a system for mounting wall panels to an existing wall, includes a plurality of fastening extrusions. Each fastening extrusion includes an extrusion base section adapted to be secured to the existing wall, two parallel, spaced apart retaining walls extending at an angle from the base section, each retaining wall including a recess on an inwardly facing surface thereof, an outwardly extending holding wall on each retaining wall, and a bent wall in the extrusion base section to an outside of each retaining wall and which is bent toward each holding wall to form a gap therebetween to receive one side edge of one wall panel. A closure member is secured to the fastening extrusion in covering relation to the holding walls, the retaining walls and a space between the retaining walls, the closure member including a center section which covers the space between the retaining walls, L-shaped cover walls extending from the center section and which cover the holding walls; one of beads and recesses formed in end edges of the holding walls; and the other of beads and recesses formed in inner surfaces at ends of the L-shaped cover walls for engagement with the one of the beads and recesses formed in the end edges of the holding walls. 
     In accordance with still another aspect of the present invention, a corner fastening extrusion for mounting wall panels to a corner of an existing wall structure of the type including first and second walls that meet at a corner, includes a first extrusion base section adapted to be secured to the first wall of the existing wall structure, a first retaining wall extending at an angle from the first extrusion base section, a first holding member on the first retaining wall, a first bent wall in the first extrusion base section which is bent toward the first holding member to form a gap therebetween to receive one side edge of one wall panel, a second extrusion base section adapted to be secured to the second wall of the existing wall structure, a second retaining wall extending at an angle from the second extrusion base section, a second holding member on the second retaining wall, a second bent wall in the second extrusion base section which is bent toward the second holding member to form a gap therebetween to receive one side edge of another wall panel, and an extrusion connecting wall which connects together the first and second extrusion base sections at an angle to each other. 
     The extrusion connecting wall is an L-shaped wall having a first wall connected with the first extrusion base section and a second wall connected with the second extrusion base section, with the first and second walls being connected with each other at a right angle. At least one of the first and second walls includes openings for receiving screws to fasten the corner fastening extrusion to the existing wall structure. 
     There is further a closure member adapted to clamp onto the first and second holding members. 
     In accordance with another aspect of the present invention, a fastening extrusion for mounting a wall panel to an existing wall, includes an extrusion base adapted to be secured to the existing wall, a first retaining wall extending at an angle from the extrusion base, a first holding member on the retaining wall, and a first bent wall extending from the extrusion base in a direction toward the holding member to form a gap between the bent wall and the holding member to receive one side edge of the wall panel. 
     The bent wall includes either an upturned wall extending from the extrusion base, or a bent section of the extrusion base. 
     In one embodiment, the extrusion base is formed as first extrusion base section and a separate disconnected extrusion base section, with the retaining wall and holding member formed on the first extrusion base section and the bent wall formed on the second extrusion base section. In another embodiment, the fastening extrusion is formed as a single, one-piece member. 
     Preferably, the retaining wall includes a lower bend that forms a bulge on a surface of the retaining wall which faces the bent wall. The bulge is at a height corresponding to an upper and of the bent wall. 
     Preferably, the retaining wall includes an upper bulge on a surface of the retaining wall which faces the bent wall for accommodating thermal expansion of the wall panel in the gap. 
     In another embodiment, a second retaining wall extends at an angle from the extrusion base in parallel, spaced relation to the first retaining wall, with a second holding member on the second retaining wall. 
     The above and other features of the invention will become readily apparent from the following detailed description thereof which is to be read in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a system for easily mounting wall panels over an existing wall, showing securement of a first wall panel at a corner; 
         FIG. 2  is a perspective view of the system for easily mounting wall panels over an existing wall, showing securement of a second wall panel adjacent the first wall panel; 
         FIG. 3  is a cross-sectional view of the system of  FIG. 1 ; 
         FIG. 4  is a cross-sectional view of the system of  FIG. 2 ; 
         FIG. 5  is a perspective view of the corner fastening extrusion of  FIG. 1 ; 
         FIG. 6  is a perspective view of the main fastening extrusion of  FIG. 2 ; 
         FIG. 7  is a perspective view of a closure member for use with the fastening extrusions of  FIGS. 5 and 6 ; 
         FIG. 8  is a perspective view of the structural support assembly of  FIGS. 1 and 2  in a finally assembled condition; 
         FIG. 9  is a perspective view of the base support of the structural support assembly of  FIG. 8 ; 
         FIG. 10  is a perspective view of the sliding support member of the structural support assembly of  FIG. 8 ; 
         FIG. 11  is a perspective view of the structural support assembly of  FIG. 8  in an initial assembly condition; 
         FIG. 12  is a cross-sectional view of a modification of the system for easily mounting wall panels over an existing wall, showing an initial condition for securement of first and second wall panels thereto; 
         FIG. 13  is a cross-sectional view of the system of  FIG. 12 , showing securement of the first wall panel at a corner; 
         FIG. 14  is a cross-sectional view of the system of  FIG. 12 , showing securement of the second wall panel adjacent the first wall panel; 
         FIG. 15  is a cross-sectional view of the system of  FIG. 12 , showing a final assembled condition for securement of the first and second wall panels thereto; 
         FIG. 16  is a cross-sectional view of a further modification of the system for easily mounting wall panels over an existing wall, showing the use of two corner fastening extrusions of the type shown in  FIG. 13 , at an inside corner of an existing wall; 
         FIG. 17  is a cross-sectional view of a still further modification of the system for easily mounting wall panels over an existing wall, showing the use of two corner fastening extrusions of the type shown in  FIG. 13 , at an outside corner of an existing wall; 
         FIG. 18  is a cross-sectional view of a yet further modification of the system for easily mounting wall panels over an existing wall, showing the use of two corner fastening extrusions of the type shown in  FIG. 13 , at an outside corner of an existing wall; 
         FIG. 18A  is a cross-sectional view of the yet further modification of the system of  FIG. 18 , but with a different decorative cover; 
         FIG. 18B  is an enlarged cross-sectional view of  FIG. 18A ; 
         FIG. 18C  is an enlarged cross-sectional view of a portion of  FIG. 18B ; 
         FIG. 19  is a cross-sectional view of a further modification of the system for easily mounting wall panels over an existing wall, showing a final assembled condition for securement of the first and second wall panels thereto; 
         FIG. 20  is a perspective view of the main fastening extrusion of  FIG. 19 ; 
         FIG. 21  is a cross-sectional view of the main fastening extrusion of  FIG. 20 ; 
         FIG. 22  is a perspective view of the first corner fastening extrusion of  FIG. 19 ; 
         FIG. 23  is a cross-sectional view of the corner fastening extrusion of  FIG. 22 ; 
         FIG. 24  is a perspective view of the second corner fastening extrusion of  FIG. 19 ; 
         FIG. 25  is a cross-sectional view of the corner fastening extrusion of  FIG. 24 ; 
         FIG. 25A  is a cross-sectional view showing a modification of the corner fastening extrusion of  FIG. 24  installed, in the manner shown in  FIG. 19 ; 
         FIG. 25B  shows a modified closure member for the corner fastening extrusion of  FIG. 25 ; 
         FIG. 26  is a cross-sectional view of a further modification of the system for easily mounting wall panels over an existing wall, showing the use of two connected together first corner fastening extrusions of the type shown in  FIG. 22 , for use at an inside corner of an existing wall in the same manner as shown in  FIG. 16 ; 
         FIG. 27  is a cross-sectional view of a still further modification of the system for easily mounting wall panels over an existing wall, showing the use of two first corner fastening extrusions of the type shown in  FIG. 22 , for use at an outside corner of an existing wall in the same manner as shown in  FIG. 17 ; 
         FIG. 28  is a cross-sectional view of a yet further modification of the system for easily mounting wall panels over an existing wall, showing the use of two first corner fastening extrusions of the type shown in  FIG. 22 , for use at an outside corner of an existing wall in the same manner as shown in  FIG. 18 ; 
         FIG. 29  is a perspective view of another embodiment of the system for easily mounting wall panels over an existing wall, using a U-channel furring with an intermediary structural support assembly; 
         FIG. 30  is a perspective view of a modification of the embodiment of  FIG. 29 , using a U-channel furring with a thermal break attachment and an intermediary structural support assembly; 
         FIG. 31  is a perspective view of another modification of the embodiment of  FIG. 29 , using a Z-channel furring with an intermediary structural support assembly; 
         FIG. 32  is a perspective view of a further embodiment of the system for easily mounting wall panels over an existing wall without any main fastening extrusions, showing a final condition for securement of first and second wall panels thereto; 
         FIG. 32A  is a perspective view of a modification of the further embodiment of  FIG. 32 ; 
         FIG. 33  is a perspective view of a connector arrangement for connecting together adjacent side edges of adjacent wall panels of  FIG. 32 ; 
         FIG. 34  is a perspective view of another connector arrangement for connecting together adjacent side edges of adjacent wall panels of  FIG. 32 ; 
         FIG. 35  is a perspective view of a still further embodiment of the system for easily mounting wall panels over an existing wall without any main fastening extrusions, showing a final condition for securement of first and second wall panels thereto; and 
         FIG. 36  is a perspective view of a yet further embodiment of the system for easily mounting wall panels over an existing wall without any main fastening extrusions, showing a final condition for securement of first and second wall panels thereto. 
         FIG. 37  is a perspective view of yet another embodiment of the system for easily mounting wall panels over an existing wall without any main fastening extrusions, showing a final condition for securement of first and second wall panels thereto. 
         FIG. 38  is a top plan view showing a first step of a method for easily mounting wall panels over an existing wall using the embodiment of  FIGS. 19-25 ; 
         FIG. 39  is a cross-sectional view of the first corner fastening extrusion of  FIG. 38 ; 
         FIG. 40  is a cross-sectional view of the second corner fastening extrusion of  FIG. 38 ; 
         FIG. 41  is a cross-sectional view of the structural support assembly of  FIG. 38 ; 
         FIG. 42  is a top plan view showing a second step of the method for easily mounting wall panels over an existing wall using the embodiment of  FIGS. 19-25 ; 
         FIG. 43  is a top plan view showing a third final step of the method for easily mounting wall panels over an existing wall using the embodiment of  FIGS. 19-25 ; 
         FIG. 44  is a cross-sectional view of the structural support assembly of  FIG. 43 ; 
         FIG. 45  is a cross-sectional view of another modification of the system for easily mounting wall panels over an existing wall; 
         FIG. 46  is a cross-sectional view of still another modification of the system for easily mounting wall panels over an existing wall; 
         FIG. 47  is a cross-sectional view of a modification of the system of  FIG. 1 ; 
         FIG. 48  is a cross-sectional view of another modification of the system of  FIG. 1 ; 
         FIG. 49  is a cross-sectional view of still another modification of the system of  FIG. 1 ; 
         FIG. 50  is a cross-sectional view of yet another modification of the system of  FIG. 1 ; 
         FIG. 51  is a cross-sectional view of a further modification of the system of  FIG. 1 ; 
         FIG. 52  is a cross-sectional view of another modification of the system for easily mounting wall panels over an existing wall; 
         FIG. 53  is a cross-sectional view of another modification of the system for easily mounting wall panels over an existing wall; 
         FIG. 54  is a cross-sectional view of another modification of the system for easily mounting wall panels over an existing wall; 
         FIG. 55  is a cross-sectional view of a modification of the system of  FIG. 19 ; 
         FIG. 55A  is an enlarged cross-sectional view of a portion of  FIG. 55 ; 
         FIG. 56  is a cross-sectional view of another modification of the system of  FIG. 19 ; 
         FIG. 57  is a cross-sectional view of still another modification of the system of  FIG. 19 ; 
         FIG. 58  is a cross-sectional view of yet another modification of the system of  FIG. 19 ; 
         FIG. 59  is a cross-sectional view of a further modification of the system of  FIG. 19 ; 
         FIG. 60  is a cross-sectional view of a still further modification of the system of  FIG. 19 ; 
         FIG. 61  is a perspective view of another modification of the system for easily mounting wall panels over an existing wall; 
         FIG. 62  is a cross-sectional view of the system of  FIG. 61 ; 
         FIG. 63  is a cross-sectional view of a modification of the system of  FIG. 61 ; 
         FIG. 64  is a cross-sectional view of a modification of the system of  FIG. 61 ; 
         FIG. 65  is a cross-sectional view of a modification of the system of  FIG. 61 ; 
         FIG. 66  is a cross-sectional view of a modification of the system of  FIG. 61 ; 
         FIG. 67  is a cross-sectional view of a modification of the system of  FIG. 61 ; 
         FIG. 68  is a cross-sectional view of a modification of the system of  FIG. 61 ; 
         FIG. 69  is a cross-sectional view of a modification of the system of  FIG. 61 ; and 
         FIG. 70  is a cross-sectional view of a modification of the system of  FIG. 61 . 
     
    
    
     DETAILED DESCRIPTION 
     Referring to the drawings in detail, and initially to  FIGS. 1-4 , there is shown a system  10  for easily mounting wall panels  12  over an existing wall  14 , which preferably includes any planar wall. Each panel  12  preferably has a rectangular parallelepiped shape, although the present invention is not limited thereby. Although wall panel  12  is shown to be planar, in fact, it can have different shapes, such as a wave shape, etc. to provide different aesthetic appearances. Wall panels  12  are formed preferably by, but not limited to, a polyethylene core  16  with a thin aluminum wall  18  covering opposite sides thereof. 
     In order to secure wall panels  12  in covering relation to existing wall  14 , system  10  includes elongated main fastening extrusions  20 , elongated corner fastening extrusions  22  and elongated intermediary structural support assemblies  24 , which can be made of any suitable material, such as aluminum, polyvinyl chloride (PVC) or the like. 
     As shown in  FIGS. 2, 4 and 6 , each main fastening extrusion  20  is preferably formed as a single, one-piece, unitary member that includes a base section  26  that seats flush against and is secured to existing wall  14 . Base section  26  has a plurality of linearly aligned openings  28  extending therealong and through which screws  30  are inserted to secure base section  26  to existing wall  14 . 
     Two, parallel, spaced apart, bent end retaining walls  32  extend outwardly at right angles from base section  26  at a center thereof and are spaced from respective side edges  34  of base section  26 . Preferably, each bent end retaining wall  32  extends about one-third of the distance from one side edge  34  to the opposite side edge  34 , although the present invention is not limited thereby. Thus, bent end retaining walls  32  separate base section  26  into a first base plate section  26   a  to the outside of one retaining wall  32 , a second base plate section  26   b  to the outside of the other retaining wall  32  and a third base plate section  26   c  between the two retaining walls  32 , as shown in  FIG. 6 . 
     An enlarged holding section  36  extends along the upper end of each retaining wall  32 . In this embodiment, enlarged holding section  36  has a triangular cross-sectional shape, so that each retaining wall  32  and its holding section  36  has the shape of an arrow in cross-section. However, the present invention is not limited to the triangular shape of holding sections  36 , and any other suitable shape can be used. Thus, each holding section  36  includes a first wall surface  36   a  that extends at right angles to an outer side of the upper end of retaining wall  32  in parallel, spaced relation to first and second base plate sections  26   a ,  26   b , a second wall surface  36   b  that extends at right angles to an inner side of the upper end of retaining wall  32  in parallel, spaced relation to third base plate section  26   c , a first inclined wall surface  36   c  that extends upwardly at an angle from first wall surface  36   a  and a second inclined wall surface  36   d  that extends upwardly at an angle from second wall surface  36   b , with inclined wall surfaces  36   c  and  36   d  meeting at an apex line  36   e . A V-shaped notch  36   f  is formed centrally along each first inclined wall surface  36   c.    
     Further, a side wall  38  extends outwardly at right angles along side edges  34  of base section  26 . The height of side walls  38  is less than the height of retaining walls  32 , the purpose for which will become apparent from the discussion hereafter. 
     Although retaining walls  32  and side walls  38  have been shown as continuous walls, a plurality of spaced apart and linearly aligned retaining walls  32  and side walls  38  can be provided instead, and in fact, a plurality of spaced apart main fastening extrusions  20  can also be used instead. 
     As shown in  FIGS. 1, 3 and 5 , each corner fastening extrusion  22  is preferably formed as a single, one-piece, unitary member that includes a base section  46  that seats flush against and is secured to existing wall  14 . Base section  46  has a plurality of linearly aligned openings  48  extending therealong and through which screws  50  are inserted to secure base section  46  to existing wall  14 . 
     Two, parallel, spaced apart, bent end retaining walls  52  extend outwardly at right angles from base section  46  at a center thereof and are spaced from respective side edges  54  of base section  46 . An enlarged holding section  56  extends along the upper end of each retaining wall  52 . In this embodiment, enlarged holding section  56  has a triangular cross-sectional shape, so that each retaining wall  52  and its holding section  56  has the shape of an arrow in cross-section. However, the present invention is not limited to the triangular shape of holding sections  56 , and any other suitable shape can be used. Thus, each holding section  56  includes a first wall surface  56   a  that extends at right angles to an outer side of the upper end of retaining wall  52  in parallel relation to base section  46 , a second wall surface  56   b  that extends at right angles to an inner side of the upper end of retaining wall  52  in parallel relation to base section  46 , a first inclined wall surface  56   c  that extends upwardly at an angle from first wall surface  56   a  and a second inclined wall surface  56   d  that extends upwardly at an angle from second wall surface  56   b , with inclined wall surfaces  56   c  and  56   d  meeting at an apex line  56   e . A V-shaped notch  56   f  is formed centrally along each first inclined wall surface  56   c.    
     Further, a side wall  58  extends outwardly at right angles along only one side edge  54  of base section  26 . The height of side wall  58  is less than the height of retaining walls  52 , the purpose for which will become apparent from the discussion hereafter. 
     Although retaining walls  52  and side walls  58  have been shown as continuous walls, a plurality of spaced apart and linearly aligned retaining walls  52  and side walls  58  can be provided instead, and in fact, a plurality of spaced apart corner fastening extrusions  22  can also be used instead. 
     As shown in  FIGS. 1-4 and 7 , a closure member  60  is provided to clamp onto enlarged holding sections  36  and  56 . Closure member  60  can be made of any suitable thin material such as aluminum. Specifically, closure member  60  includes first and second clamping members  62  and  64  connected together in parallel, spaced apart relation by a connecting plate  65 . Each clamping member  62  and  64  includes a sitting wall  66  that sits on top of apex line  36   e ,  56   e  in parallel relation to base section  26 ,  46 , an outer covering wall  68  that extends adjacent to first inclined walls  36   c  and  56   c  at a right angle to sitting wall  66  and which extends down from the outer edge of sitting wall  66  to a position slightly below first walls  36   a  and  36   b , and an inclined inner lock-down wall  70  that extends adjacent to second inclined walls  36   d  and  56   d  and which extends down from the inner edge of sitting wall  66  at the same angle as second inclined walls  36   d  and  56   d  so as to be positioned thereon. The free lower edge of inclined inner lock-down wall  70  includes a bent tab  72  that wraps to the underside of second walls  36   b  and  56   b  so as to clamp each clamping member  62  and  64  to a respective enlarged holding section  36 ,  56 . Connecting plate  65  is arranged parallel to base section  26 ,  46  and connects together inclined inner lock-down walls  70  of closure members  60 . 
     As shown in  FIGS. 1-4 and 8-10 , each structural support assembly  24  includes a base support  76  that is secured to existing wall  14  and a sliding support member  78  that is slidably retained within base support  76 . 
     Base support  76  includes an elongated base plate  80  having openings  82  therein through which screws  84  extend to secure base plate  80  to existing wall  14 , and L-shaped retaining walls  86   a  and  86   b  that extend outwardly from opposite side edges of base plate  80 . Specifically, each L-shaped retaining wall  86   a ,  86   b  includes a first wall  88   a ,  88   b  that extends at a right angle from a side edge of base plate  80  and an inwardly extending second wall  90   a ,  90   b  that extends toward the opposite side edge of base plate  80  in parallel spaced apart relation to base plate  80  with a space  92  therebetween, with free edges of second walls  90   a ,  90   b  spaced apart by a distance D. Preferably, inwardly extending second wall  90   b  has a greater width than inwardly extending second wall  90   a.    
     Sliding support member  78  includes an inverted U-shaped plate  94  that fits in the space between the spaced-apart free edges of second walls  90   a ,  90   b , and wing plates  96   a ,  96   b  at opposite free ends at the side edges of inverted U-shaped plate  94 , with wing plates  96   a ,  96   b  slidably retained in spaces  92 . Preferably, wing plate  96   b  has a greater width than wing plate  96   a . It will be appreciated that the distance between free edges of wing plates  96   a ,  96   b  is less than the distance between first walls  88   a ,  88   b  of each L-shaped retaining wall  86   a ,  86   b  so as to permit side to side sliding of sliding support member  78  within base support  76 . 
     An adhesive member  98 , which can be a double sided tape, an adhesive or any other securing means, secured on top of inverted U-shaped plate  94  of sliding support member  78 , for securement of wall panel  12  thereon. 
     It will be appreciated that, base section  26 , base section  46  and/or base support  76  may be made of a metal material, and therefore, would be thermally conductive, that is, would undesirably transfer heat and cold from the outside to existing wall  14 . Therefore, a thermal break insulation  99  can be positioned between existing wall  14  and base section  26 , base section  46  and/or base support  76  so that base section  26 , base section  46  and/or base support  76  are not in direct contact with existing wall  14  of the building, with screws  30 ,  50 ,  84  also inserted through the thermal insulation break  99 . Any suitable thermally insulating material can be used, for example, ethylene propylene diene monomer (EPDM), neoprene, polyisoprene, natural rubber, synthetic rubber sold under the trademark VITON, nitrile rubber, silicone, plastics or the like. 
     Referring now to  FIGS. 12-14 , there is shown a system  10 ′ which is a modification of the system  10  of  FIGS. 1-11 , and in which like elements are referred to by the same numerals, but in which modified elements are referred to by the same numerals with a prime (′) added, and a detailed description of the like elements is not provided. 
     System  10 ′ differs from system  10  only as to main fastening extrusions  20 ′ and corner fastening extrusions  22 ′. All other elements are identical to those in system  10 . 
     As shown in  FIGS. 12 and 14 , each main fastening extrusion  20 ′ is preferably formed as a single, one-piece, unitary member that includes a base section  26  that seats flush against and is secured to existing wall  14 . Base section  26  has a plurality of linearly aligned openings  28  extending therealong and through which screws  30  are inserted to secure base section  26  to existing wall  14 . 
     Two, parallel, spaced apart, bent end retaining walls  32  extend outwardly at right angles from base section  26  at a center thereof and are spaced from respective side edges  34  of base section  26 . Preferably, each bent end retaining wall  32  extends slightly more than about one-third of the distance from one side edge to the opposite side edge, although the present invention is not limited thereby. Thus, bent end retaining walls  32  separate base section  26  into a first base plate section  26   a  to the outside of one retaining wall  32 , a second base plate section  26   b  to the outside of the other retaining wall  32  and a third base plate section  26   c  between the two retaining walls  32 . 
     The enlarged holding sections  36  of main fastening extrusions  20  are eliminated, and in place thereof, a hold down wall  36 ′ is connected at the upper end of each retaining wall  32 ′. Hold down wall  36 ′ extends toward the respective outer side edge  34  and is provided in parallel, spaced relation with base section  26 . 
     Also, side walls  38  of main fastening extrusions  20  are eliminated, and instead, first and second base plate sections  26   a  and  26   b  are each bent in an arcuate shape immediately adjacent the respective retaining wall  32  to form arcuate bends  37 ′ that are bent in an arc towards the respective hold down wall  36 ′, thereby creating a space  39 ′ between the apex of each arcuate bend  37 ′ and its respective hold down wall  36 ′. 
     Although retaining walls  32 , hold down walls  36 ′ and arcuate bends  37 ′ have been shown as continuous walls, a plurality of spaced apart and linearly aligned retaining walls  32 , hold down walls  36 ′ and arcuate bends  37 ′ can be provided instead. 
     A closure member  60   a ′ is provided to clamp onto retaining walls  32  and hold down walls  36 ′. Closure member  60   a ′ can be made of any suitable thin material such as aluminum. Specifically, closure member  60   a ′ includes a U-shaped center section  65   a ′ that fits snugly between retaining walls  32 , and L-shaped cover walls  62   a ′ and  64   a ′ connected to the free edges of U-shaped center section  65   a ′ and which seat on top of and wrap around the free edges of hold down walls  36 ′. As a result, the gap between retaining walls  32  is covered. 
     As shown in  FIGS. 12 and 13 , each corner fastening extrusion  22 ′ is preferably formed as a single, one-piece, unitary member that includes a base section  46  that seats flush against and is secured to existing wall  14 . Base section  46  has a plurality of linearly aligned openings  48  extending therealong and through which screws  50  are inserted to secure base section  46  to existing wall  14 . 
     A single bent end retaining wall  52  extends outwardly at right angles from one side edge  54  of base section  46 . The enlarged holding sections  56  of corner fastening extrusions  22  are eliminated, and in place thereof, a hold down wall  56 ′ is connected at the upper end of each retaining wall  52 . Hold down wall  56 ′ extends toward the opposite side edge  54  and is provided in parallel, spaced relation with base section  46 . 
     Also, side walls  58  of corner fastening extrusions  22  are eliminated, and instead, base section  46  is bent in an arcuate shape immediately adjacent retaining wall  52  to form an arcuate bend  57 ′ that is bent in an arc towards hold down wall  56 ′, thereby creating a space  59 ′ between the apex of each arcuate bend  57 ′ and hold down wall  56 ′. 
     Although retaining walls  52 , hold down walls  56 ′ and arcuate bends  57 ′ have been shown as continuous walls, a plurality of spaced apart and linearly aligned retaining walls  52  hold down walls  56 ′ and arcuate bends  57 ′ can be provided instead. 
     A closure member  60   b ′ is provided to clamp onto retaining wall  52  and hold down wall  56 ′. Closure member  60   b ′ can be made of any suitable thin material such as aluminum. Specifically, closure member  60   b ′ includes a first plate  65   b ′ that seats against the outside of retaining wall  32  and an L-shaped cover wall  62   a ′ connected to the outer free edge of first plate  65   b ′ and which seats on top of and wraps around the free edge of hold down wall  36 ′. 
     Each structural support assembly  24  is of identical construction to that described in system  10 , and therefore, a further explanation is omitted. 
     Assembly of wall panels  12  occurs in the same manner as described above in the embodiment of  FIGS. 1-11 . 
     As a result, wall panels  12  are securely and tightly held in place without any play between main fastening extrusions  20 ′ and corner fastening extrusions  22 ′. 
     Referring now to  FIG. 16 , there is shown a system for easily mounting wall panels over an existing wall, showing the use of two corner fastening extrusions  22 ′ at an inside corner of existing wall  14 . In this case, the corners of the two corner fastening extrusions  22 ′ where each bent end retaining wall  52  meets its respective hold down wall  56 ′ are in contact with each other. As a result, there is a rectangular parallelepiped space  61 ′ between bent end retaining walls  52 , which is shown to have a square transverse cross-sectional configuration. Screws  50  are omitted for the sake of clarity. 
     Referring now to  FIG. 17 , there is shown a system for easily mounting wall panels over an existing wall, showing the use of two corner fastening extrusions  22 ′ at an outside corner of existing wall  14 . In this case, arcuate bend  57 ′ of one corner fastening extrusion  22 ′ is in overlapping relation to bent end retaining wall  52  of the other corner fastening extrusion  22 ′. 
     Referring now to  FIGS. 19-25 , there is shown a system  10 ″ which is a modification of the system  10 ′ of  FIGS. 12-18 , and in which like elements are referred to by the same numerals, but in which modified elements are referred to by the same numerals with a double prime (″) added, and a detailed description of the like elements is not provided. System  10 ″ differs from system  10 ′ in two respects, and all other elements are identical to those in system  10 ′ and therefore referred to by the same reference numerals. 
     Specifically, as shown in  FIGS. 19-21 , each retaining wall  32 ″ of main fastening extrusions  20 ″ is provided with a lower arcuate bend  33 ″ that produces an outward bulge  33   a ″ on the outwardly facing surface thereof and a recess  33   b ″ on the inwardly facing surface thereof. Outward bulge  33   a ″ is at the same height as the apex of the adjacent arcuate bend  37 ″ formed in base section  26 ″ in spaced relation from the respective side edge  34 ″ of base section  26 ″. This serves a twofold purpose. Specifically, outward bulge  33   a ″ with the apex of arcuate bend  37 ″ functions to support the lower surface of wall panel  12 , and also, inward recess  33   b ″ serves to receive and hold a lip  67 ″ at the lower end of U-shaped center section  65   a ″ of closure member  60   a ″ to releasably lock closure member  60   a ″ therein. L-shaped cover wall  62   a ″ of closure member  60   a ″ is the same as L-shaped cover wall  62   a ′ of closure member  60   a′.    
     In addition, each retaining wall  32 ″ is provided with an upper bulge  35 ″ on the outwardly facing surface thereof immediately above outward bulge  33   a ″, and against which the edge of wall panels  12  abut. The reason for such outward bulge  35 ″ is as follows. When the temperature increases, the thin aluminum walls  18  of wall panel  12  expand at a greater rate than polyethylene core  16  thereof. As a result, thin aluminum walls  18  tend to expand in a direction toward retaining wall  32 ″. However, if the outer surface of retaining wall  32 ″ is planar, there is no room for expansion. By providing outward bulge  35 ″, polyethylene core  16  abuts against outward bulge  35 ″, but because of the sloping walls of outward bulge  35 ″, aluminum walls  18  can expand in a direction past the outer edge of polyethylene core  16  in a direction toward the outer surface of retaining wall  32 ″. 
     Of course, an enlarged holding section  36 ″ extends along the upper end of each retaining wall  32 ″, as described above. 
     In the same manner, the retaining wall  52 ″ of each corner fastening extrusion  22 ″ shown in  FIGS. 19, 22 and 23 , is provided with a lower arcuate bend  53 ″ that produces an inward bulge  53   a ″ on the inwardly facing surface thereof and a recess  53   b ″ on the outwardly facing surface thereof, in a similar manner as arcuate bend  33 ″, and an upper bulge  55 ″ on the inwardly facing surface thereof immediately above outward bulge  53   a ″, in the same manner as upper bulge  35 ″. Thus, outward bulge  53   a ″ is at the same height as the apex of the adjacent arcuate bend  57 ″ formed in base section  46 ″ in spaced relation from the respective side edge  54 ″ of base section  46 ″. Of course, an enlarged holding section  56 ″ extends along the upper end of each retaining wall  52 ″, as described above. A closure member  60   b ″ which is identical to closure member  60   a ″ is provided, except that the lower end of closure member  60   b ″ includes a lower lip  67 ″ which is received and held in recess  53   b ″, as shown in  FIG. 19 . 
     In addition, as shown in  FIGS. 19, 24 and 25 , a modified corner fastening extrusion  22   a ″ is shown at the closing end of existing wall  14 . Corner fastening extrusion  22   a ″ is identical to corner fastening extrusion  22 ″ with the except that corner fastening extrusion  22   a ″ further includes an L-shaped wall  51 ″ extending to the outside of retaining wall  52 ″, with one wall  51   a ″ of L-shaped wall  51 ″ continuing as an extension of base section  46 ″ but on the opposite side of retaining wall  52 ″ and secured to existing wall  14  by screws  50 , and the other wall  51   b ″ of L-shaped wall  51 ″ extending from the free edge of wall  51   a ″ and positioned against the adjacent side wall  14   a  of existing wall  14 . Wall  51   b ″ also includes a lower arcuate bend  53 ″ that produces an outward bulge  53   a ″ on the outwardly facing surface thereof and a recess  53   b ″ on the inwardly facing surface thereof, in the same manner as arcuate bend  33 ″, and an upper bulge  55 ″ on the outwardly facing surface thereof immediately above outward bulge  53   a ″, in the same manner as upper bulge  35 ″. In this manner, a closure member is captured between retaining wall  52 ″ and wall  51   b ″ in the same manner as discussed above in relation to closure member  60   a ″ and main fastening extrusion  20 ″. 
       FIG. 25A  shows a slight modification to corner fastening extrusion  22   a ″ in which L-shaped wall  51 ″ and retaining wall  52 ″ are formed as a single, one-piece unit, and base section  46 ″ with arcuate bend  57 ″ is formed as a separate single, one-piece unit, with each being secured separately. In this case, in order to assemble the same, base section  46 ″ with arcuate bend  57 ″ is first secured to wall  14  by any suitable means, such as screws, adhesive or the like, and wall panel  12  is positioned thereover, as shown. Then, the single, one-piece unit of L-shaped wall  51 ″ and retaining wall  52 ″ are assembled with enlarged holding section  56 ″ being positioned over wall panel  12 , and with the end of wall panel  12  abutting against upper bulge  55 ″. A screw  50  is then used to secure the single, one-piece unit of L-shaped wall  51 ″ and retaining wall  52 ″ to existing wall  14 , as shown. Thereafter, closure member  60   a ″ is assembled therewith, with inward recesses  53   b ″ serving to receive and hold a lip  67 ″ at the lower end of U-shaped center section  65   a ″ of closure member  60   a ″ to releasably lock closure member  60   a ″ therein. 
       FIG. 25B  shows a modified closure member  60   a   1 ″ in which two parallel, spaced apart walls  69   a ″ extend from the undersurface of U-shaped center section  65   a ″, each having an outwardly turned tab  67   a ″ which engages within a respective recess  53   b ″ in order to lock closure member  60   a   1 ″ to corner fastening extrusion  22   a ″. In this arrangement, the leftmost L-shaped cover wall  62   a ″ shown in  FIG. 19  is replaced by a U-shaped cover wall  62   a   1 ″ that acts as a finishing wall to cover an outer surface of a respective retaining wall  53 ″ and that includes a recess  62   b   1 ″ for receiving lower arcuate bend  53 ″. 
     It will be appreciated that the aspects of system  10 ″ of lower arcuate bend  53 ″ with outward bulge  53   a ″ and recess  53   a ″, along with upper bulge  55 ″, can be used with the first embodiment of  FIGS. 1-11  as well. 
     Referring now to  FIGS. 18, 18A and 18B , there is shown a system for easily mounting wall panels over an existing wall, showing a modified construction for securement of the wall panels at an outside corner of an existing corner wall  14 , using the basic construction shown in  FIGS. 19-25 . Specifically, two corner fastening extrusions  22   c ″ and  22   d ″ are connected together by an elongated L-shaped wall  63 ″ that wraps around the corner of existing wall  14  to form a singe, one-piece, corner fastening extrusion assembly  69 ″. L-shaped wall  63 ″ includes connected right angle wall panels  63   a ″ and  63   b ″ connected together at one end and connected at their opposite ends to the lower ends of retaining walls  52 ″ so that base sections  46 ″ of the two corner fastening extrusions  22   c ″ and  22   d ″ are at right angles to each other and seat on the right angle existing walls  14 . The securing screws are omitted in  FIGS. 18 and 18A  for the sake of clarity, but are shown in  FIG. 18B . 
     Each base section  46 ″ has a plurality of linearly aligned openings  48 ″ extending therealong and through which screws  50  can be inserted to secure base section  46 ″ to existing wall  14 . An arcuate bend  57 ″ is formed in each base section  46 ″ in the same manner as discussed previously in  FIGS. 19-25 . 
     A single bent end retaining wall  52 ″ extends outwardly at right angles from each base section  46 ″, and a hold down wall  56 ″ is connected at the upper end of each retaining wall  52 ″ and faces outwardly away from the corner. Hold down wall  56 ″ is provided in parallel, spaced relation with base section  46 ″. Retaining wall  52 ″ is provided with the aforementioned lower arcuate bend  53 ″ and upper bulge  55 ″ on the outwardly facing surface thereof immediately above outward bulge  53   a ″, in the same manner as previously discussed. Thus, outward bulge  53   a ″ is at the same height as the apex of the adjacent arcuate bend  57 ″ formed in base section  46 ″. 
     Alternatively, corner fastening extrusions  22   c ″ and  22   d ″ can be formed separately from L-shaped wall  63 ″ in the manner shown in  FIG. 25A . 
     To assemble corner fastening extrusion assembly  69 ″ with corner wall  14 , it is first assumed that wall panel  12   a  in  FIG. 18B  extends from a main fastening extrusion  20 ″ (not shown) below it. Then, corner fastening extrusion assembly  69 ″ is positioned over corner wall  14 , as shown, with the space between hold down wall  56 ″ and arcuate bend  57 ″ of corner fastening extrusion  22   c ″ receiving the free end of wall panel  12   a . Thereafter, screws  50  are inserted through openings in wall panels  63   a ″ and  63   b ″ of elongated L-shaped wall  63 ″ and in base section  46 ″ of corner fastening extrusion  22   d ″ to the outside of arcuate bend  57 ″ thereof. Then, one end of the other wall panel  12   b  is inserted within the space between hold down wall  56 ″ and arcuate bend  57 ″ of corner fastening extrusion  22   d″.    
     Alternatively, in the event that the starting point for assembly of the wall panels begins at the corner, screws  50  are first inserted through openings in wall panels  63   a ″ and  63   b ″ of elongated L-shaped wall  63 ″ and in base section  46 ″ of corner fastening extrusion  22   d ″ to the outside of arcuate bend  57 ″ thereof. Then, one end of each wall panel  12   a  and  12   b  is inserted within the respective space between hold down wall  56 ″ and arcuate bend  57 ″ of corner fastening extrusions  22   c ″ and  22   d″.    
     Thereafter, an L-shaped closure member made of any suitable thin material such as aluminum, is secured over corner fastening extrusion assembly  69 ″ for decorative purposes. In the embodiment of  FIG. 18 , an L-shaped closure member  60   c ′ is provided, with free ends thereof received and held in recesses  53   b″.    
     In  FIGS. 18A and 18B , an L-shaped closure member  60   d ′ is provided for decorative purposes, in which the free ends thereof have downturned walls  60   d   1 ′ which engage over the ends of hold down walls  56 ″. Preferably, the inner ends of downturned walls  60   d   1 ′, as best shown in  FIG. 18C , have inwardly directed tabs or beads  60   d   2 ′ that engage within cut-away recesses  56   a ″ at the free ends of enlarged holding section  56 ″. 
     Of course, it will be appreciated that, in all of the embodiments of the present application, a thermal break insulation  99  can be positioned between existing wall  14  and base section  26 , base section  46  and/or base support  76  so that base section  26 , base section  46  and/or base support  76  are not in direct contact with existing wall  14  of the building. 
       FIG. 26  is a cross-sectional view of a further modification of the system for easily mounting wall panels over an existing wall, showing the use of two connected together first corner fastening extrusions  20   a ″ of the type shown in  FIG. 22 , for use at an inside corner of an existing wall in the same manner as shown in  FIG. 16 ; 
       FIG. 27  is a cross-sectional view of a still further modification of the system for easily mounting wall panels over an existing wall, showing the use of two first corner fastening extrusions  20   a ″ of the type shown in  FIG. 22 , for use at an outside corner of an existing wall in the same manner as shown in  FIG. 17 ; 
       FIG. 28  is a cross-sectional view of a yet further modification of the system for easily mounting wall panels over an existing wall, showing the use of two first corner fastening extrusions  20   a ″ of the type shown in  FIG. 22 , for use at an outside corner of an existing wall in the same manner as shown in  FIG. 18 . 
     It will be appreciated that although only shown in the first embodiment of  FIGS. 1-4 , in all of the above embodiments, prior to securing a main fastening extrusion  20 ,  20 ′ or  20 ″, a corner fastening extrusion  22 ,  22 ′,  22 ″ or  22   a ″ or base support  78  of structural support assembly  24  to existing wall  14 , a thermal break insulation  99  is inserted over existing wall  14 , and then main fastening extrusion  20 ,  20 ′ or  20 ″, a corner fastening extrusion  22 ,  22 ′,  22 ″ or  22   a ″ or base support  78  of structural support assembly  24  is positioned over the thermal insulation break  99 , with screws  30 ,  50 ,  84  also inserted through the thermal insulation break  99 . 
     When installing wall panels over an existing wall, it is often necessary to provide a spacing between the wall panels and the existing wall. This spacing can be provided for ventilation, to provide for water run-off, to provide insulation therein, and to provide a thermal barrier. Typically, Z-furring or U-channel furring is used to provide this spacing between the existing wall and the wall panels. However, it has been found that this arrangement is not entirely satisfactory. For example, although it is known to combine insulation with the Z-furring or U-channel furring, such insulation is not securely held therein, and must be secured by screws, adhesive or the like. Further, the outwardly extending foot walls of the Z-furring or U-channel furring are secured directly to the existing wall, thereby providing thermal transfer directly with the existing wall. In addition, such Z-furring or U-channel furring may not be entirely satisfactory in providing thermal insulation, and in many cases, it is desirable to increase the thermal insulation. It is also not possible to change the spacing between the walls panels and existing wall since the Z-furring or U-channel furring are of fixed dimensions. 
     U.S. patent application Ser. No. 15/047,024, filed Feb. 18, 2016 and entitled THERMAL BREAK SYSTEM FOR WALL PANELS SECURED TO AN EXISTING WALL, the entire disclosure of which is incorporated herein by reference, to the same applicant herein, attempts to solve this problem by providing additional thermal insulation between the existing wall and the outside in a system utilizing Z-furring, U-channel furring, and T-furring. 
     The aforementioned sliding arrangement can be used in such a system utilizing Z-furring, U-channel furring, and T-furring. 
     Specifically, as shown in  FIG. 29 , in order to provide a spacing  151  between the wall panels (not shown) and the existing wall  114 , for example, for ventilation, to provide for water run-off, to provide insulation therein, and to provide a thermal barrier, a U-channel furring  152  is connected between existing wall  114  and the wall panels. 
     Specifically, U-channel furring  152  includes two parallel, spaced apart spacing walls  154  and  156  connected together by a common transverse connection wall  158  at one end of walls  154  and  156 , as is known. Also, outwardly extending foot walls  160  are connected to the opposite free ends of spaced apart walls  154  and  156 , as is also known. However, in accordance with one aspect of said U.S. patent application Ser. No. 15/047,024, opposing inwardly extending foot walls  161  extend inwardly of walls  154  and  156  in a coplanar arrangement with outwardly extending foot walls  160 , and opposite extension walls  162  are formed as a continuation of common transverse wall  158  and extend outwardly of spaced apart walls  154  and  156 . In this manner, insulation  273  (see  FIG. 53 ) can be positioned in spacing  151  so as to be tightly held between foot walls  160  and extension walls  162  so as to prevent escape thereof, and to keep the insulation properly positioned at all times. Further, the insulation is tightly held between common transverse wall  158  and inwardly extending foot walls  161 . This eliminates the need for any additional members to hold the insulation in place, such as screws, adhesives, etc., while also eliminating any extra labor that would result therefrom. 
     U-channel furring  152  is made of a metal material, and therefore, is thermally conductive, that is, will transfer heat and cold from the outside to existing wall  114 , which is undesirable. Therefore, a generally J-shaped thermal insulation cover  166  is positioned around each foot wall  160 , and is made of a thermally insulating material so that foot walls  160  are not in direct contact with existing wall  114  of the building. Any suitable thermally insulating material can be used, for example, ethylene propylene diene monomer (EPDM), neoprene, polyisoprene, natural rubber, synthetic rubber sold under the trademark VITON, nitrile rubber, silicone, plastics or the like. 
     As a result of the above arrangement, a space is further provided between the insulation and existing wall  114 , which allows for water and air circulation. In this regard, a thin waterproof membrane  171  can be provided against existing wall  114 . 
     With the above arrangement, elongated base plate  180  of base support  176  of each intermediary structural support assembly  124  is formed by common transverse connection wall  158  and opposite extension walls  162  of U-channel furring  152 , with L-shaped retaining walls  186   a ,  186   b  extending outwardly from side edges of opposite extension walls  162 . Further, in order to enhance easy insertion of sliding support member  178  therein, the free end of L-shaped retaining wall  186   b  is angled outwardly.  FIG. 29  also shows an adhesive member  198 , which can be a double sided tape, an adhesive or any other securing means, secured on top of inverted U-shaped plate  194  of sliding support member  178 , for securement of a wall panel thereon. 
     Of course, it will be appreciated that, with the arrangement of  FIG. 29 , a similar U-channel furring  152  will be provided below each corner fastening extrusion and main fastening extrusion with the base section thereof formed by common transverse connection wall  158  and L-shaped retaining walls  186   a ,  186   b  of U-channel furring  152 . 
     Referring now to  FIG. 30 , a further thermal break attachment  274  is connected between common transverse wall  258  of U-channel furring  252  and elongated base plate  280  of base support  276  of each intermediary structural support assembly  224 . 
     U-channel furring  252  includes two parallel, spaced apart spacing walls  254  and  256  connected together by a common transverse connection wall  258  at one end of walls  254  and  256 , as is known. Also, outwardly extending foot walls  260  are connected to the opposite free ends of spaced apart walls  254  and  256 , as is also known. Opposing inwardly extending foot walls (not shown) can also be provided so as to extend inwardly of walls  254  and  256  in a coplanar arrangement with outwardly extending foot walls  260 , and opposite extension walls  262  are formed as a continuation of common transverse wall  258  and extend outwardly of spaced apart walls  254  and  256 . In this manner, insulation (not shown) can be positioned in spacing  251  so as to be tightly held between foot walls  260  and extension walls  262  so as to prevent escape thereof, and to keep the insulation properly positioned at all times. Further, the insulation is tightly held between common transverse wall  258  and the inwardly extending foot walls. This eliminates the need for any additional members to hold the insulation in place, such as screws, adhesives, etc., while also eliminating any extra labor that would result therefrom. 
     U-channel furring  252  is made of a metal material, and therefore, is thermally conductive, that is, will transfer heat and cold from the outside to existing wall  214 , which is undesirable. Therefore, a generally J-shaped thermal insulation cover  266  is positioned around each foot wall  260 , and is made of a thermally insulating material so that foot walls  260  are not in direct contact with existing wall  214  of the building. Any suitable thermally insulating material can be used, for example, ethylene propylene diene monomer (EPDM), neoprene, polyisoprene, natural rubber, synthetic rubber sold under the trademark VITON, nitrile rubber, silicone, plastics or the like. 
     Thermal break attachment  274  is formed by at least an outer wall  275  and a parallel, spaced apart inner wall  277  connected together by outer transverse walls  281  and preferably, also by inner transverse walls  283 . As shown in  FIG. 30 , thermal break attachment  274  also includes an intermediate wall  285  in parallel spaced apart relation to and between outer wall  275  and inner wall  277 , and also connected with transverse walls  281  and  283 . 
     The upper surface of common transverse wall  258  of U-channel furring  252  includes parallel, spaced apart openings  288  having a dovetail cross-sectional configuration, and the lower surface of inner wall  277  of thermal break attachment  274  is provided with projections  290  having a dovetail cross-sectional configuration complementary in shape and dimensions to openings  288  to slidably lock therein. 
     Elongated base plate  280  of base support  276  of elongated intermediary structural support assembly  224  sits on top of outer wall  275  of thermal break attachment  274  and includes openings  282  therein through which screws  284  extend to secure base plate  280  to outer wall  275 , inner wall  277  and intermediate wall  285 . 
     Of course, it will be appreciated that, with the arrangement of  FIG. 30 , a similar U-channel furring  252  will be provided below each corner fastening extrusion and main fastening extrusion. 
     Referring now to  FIG. 31 , there is a shown a system  310  according to the present invention for mounting wall panels over an existing planar wall  314  through Z-furring  352  with thermal breaks. All of the elements shown in  FIG. 31  are identical to those in  FIG. 29  and use the same numerals augmented by a value of 200, except that U-channel furring  152  is replaced with Z-furring  352 , and therefore, a detailed description of the common elements will be omitted for the sake of brevity. 
     Z-furring  352  includes a single spacing wall  354  that replaces the two parallel, spaced apart walls  154  and  156  of U-channel furring  152 , with a transverse connection wall  358  at one end thereof and extending to the right side of wall  354  in  FIG. 31 , and an extension wall  362  formed as a continuation of transverse wall  358  and extending to the opposite left side of wall  354  in  FIG. 31 . An outwardly extending transverse foot wall  360  extends from the opposite end of wall  354  to the left side of wall  354  in  FIG. 31 , and a coplanar, inwardly extending transverse foot wall  361  is also connected to the opposite free end of wall  354 , and extends to the right side of wall  354  in  FIG. 31 . In this manner, insulation is tightly held between foot wall  360  and extension wall  362  so as to prevent escape thereof, and to keep insulation properly positioned at all times. Further, insulation is tightly held between transverse wall  358  and inwardly extending foot wall  361 . This eliminates the need for any additional members to hold the insulation in place, such as screws, adhesives, etc., while also eliminating any extra labor that would result therefrom. 
     As with U-channel furring  152 , elongated base plate  380  of base support  376  of each intermediary structural support assembly  324  is formed by common transverse connection wall  358  and extension wall  362  of Z-channel furring  352 , with L-shaped retaining walls  386   a ,  386   b  extending outwardly from side edges of opposite extension walls  362 . Further, in order to enhance easy insertion of sliding support member  378  therein, the free end of L-shaped retaining wall  386   b  is angled outwardly.  FIG. 31  also shows an adhesive member  398 , which can be a double sided tape, an adhesive or any other securing means, secured on top of inverted U-shaped plate  394  of sliding support member  378 , for securement of a wall panel thereon. 
     Of course, it will be appreciated that, with the arrangement of  FIG. 31 , a similar Z-channel furring  352  will be provided below each corner fastening extrusion and main fastening extrusion. 
     Further, a thermal break attachment similar to thermal break attachment  274  can be provided with this embodiment as well. 
     Referring now to  FIG. 32 , there is shown a further embodiment of a system  410  for easily mounting wall panels over an existing wall, showing a final condition for securement of first and second wall panels  12   a ,  12   b  thereto. 
     As shown therein, main fastening extrusions are eliminated, and there are only two panels  12   a ,  12   b  assembled without any main fastening extrusion therebetween. System  410  includes corner fastening extrusions  422  which are identical to corner fastening extrusions  22   a ″ of  FIGS. 24 and 25 , and intermediary structural support assemblies  424  which are identical to intermediary structural support assemblies  224  of  FIG. 30 . With this arrangement, the leftmost corner fastening extrusion  422   a  is installed on existing wall  14 , and base supports  476  of intermediary structural support assemblies  424   a  and  424   b  are then installed in spaced relation to leftmost corner fastening extrusion  422   a . Then, sliding support members  478  are inserted into these base supports  476  to the extreme right thereof. Wall panel  12   a  is then connected to base supports  476  and slid to the left with base supports  476  to the position shown in  FIG. 32 . 
     Thereafter, base supports  476  of intermediary structural support assemblies  424   c  and  424   d  are then installed in spaced relation to wall panel  12   a . Then, sliding support members  478  are inserted into base supports  476  of structural support assemblies  424   c  and  424   d  to the extreme right thereof. Wall panel  12   b  is then connected to base supports  476  and slid to the left with base supports  476  to the position shown in  FIG. 32 , with the left edge of wall panel  12   a  immediately adjacent the right edge of wall panel  12   a . Thereafter, rightmost corner fastening extrusion  422   b  is installed on existing wall  14  with the right edge of wall panel  12   b.    
     Further, system  410  can be used with many linearly aligned wall panels. For example, a further corner fastening extrusion (not shown) which is oriented the same as corner fastening extrusion  422   a  can be positioned adjacent the right side of corner fastening extrusion  422   b , and two more wall panels can be assembled in the same manner, and so on. In such case, corner fastening extrusions  422  effectively become main fastening extrusions, and a cover can be provided to cover adjacent corner fastening extrusions  422 . 
     Further, adjacent edges of adjacent walls panels  12   a  and  12   b  can be further connected together, as shown in  FIG. 33 , by a connecting plate  413  which fits within slots  415  of adjacent edges of wall panels  12   a  and  12   b.    
     Alternatively, as shown in  FIG. 34 , a connector  417  can be used to connect together adjacent edges of wall panels  12   a  and  12   b . In such case, connector  417  includes a first U-shaped connector  417   a  that engages the side edge and top and bottom of wall panel  12   a , a second U-shaped connector  417   b  that engages the side edge and top and bottom of wall panel  12   a , and a connecting plate  417   c  that connects together first and second U-shaped connectors  417   a  and  417   b.    
     As shown in  FIG. 32A , inwardly turned bent end sections  412  can be provided at side and end edges of wall panels  12   a  and  12   b  so as to be in abutting relation to each other. This also eliminates the corner fastening extrusions. 
     Referring now to  FIG. 35 , there is shown a further embodiment of the system  510  for easily mounting wall panels over an existing wall, showing a final condition for securement of first and second wall panels  12   a ,  12   b  thereto. 
     In this embodiment, base supports  576  of intermediary structural support assemblies  524  for adjacent wall panels  12   a  and  12   b  are oriented 180 degrees out of phase with each other. Further, inwardly extending second wall  590   a  of each base support  576  includes an L-shaped extension wall  579  having a first wall  579   a  that is coplanar with and forms an outward extension of second wall  590   a  and a second wall  579   b  that extends at right angles outwardly from the free end of first wall  579   a  and which functions as a stop limit for the edge of the respective wall panel  12   a ,  12   b.    
     Alternatively, as shown in  FIG. 36 , in an alternative system  610 , L-shaped extension walls  579  can be replaced with a common plate  679  that sits on top of adjacent second walls  690   a  of adjacent base supports  676  of intermediary structural support assemblies  624 , and two parallel, spaced apart walls  679   a  and  679   b  extend outwardly from common plate  679  to function as stop limits for the edges of the respective wall panels  12   a ,  12   b.    
     A further alternative system  710  is shown in  FIG. 37 , in which each structural support assembly  724  includes a base support  776  that is secured to existing wall  14  and a sliding support member  778  that is slidably retained within base support  776 . Base support  776  is identical with base support  76  except that inwardly extending second wall  790   a  of each base support  776  includes a J-shaped extension wall  779  having a first wall  779   a  that is coplanar with and forms an outward extension of second wall  790   a , a second wall  779   b  that extends at right angles outwardly from the free end of first wall  779   a  and which functions as a stop limit for the edge of the respective wall panel  12 , and a third wall  779   c  which turns inwardly at a right angle from second wall  779   b  and which engages within a slot  12   d  of a wall panel  12 . 
     An end extrusion  723  includes a base section  746  that seats flush against and is secured to existing wall  14 . A first wall  725  extends upwardly from base section  746 , and a second J-shaped extension wall  727  has a first wall  727   a  that is in parallel, spaced relation to base section  746 , a second wall  727   b  that extends at right angles outwardly from the free end of first wall  727   a  and which functions as a stop limit for the edge of the respective wall panel  12 , and a third wall  727   c  which turns inwardly at a right angle and which engages within a slot  12   d  of a wall panel  12 . 
     In assembling wall panels  12  with this arrangement, base supports  776  are first secured to wall panel  12  in spaced apart relation, as shown, by screws  84  through openings  782  in base supports  776 . It will be appreciated that adjacent base supports  776  are assembled such that L-shaped retaining walls  786   a  are closest to each other. Support members  778 , which are identical to support members  78 , are then assembled in sliding relation with base supports  776  as discussed above, with wing plates  796   b  positioned entirely in spaces  792  between second walls  790   b  and base plate  780 . An adhesive member  798 , which can be a double sided tape, an adhesive or any other securing means, is secured on top of each inverted U-shaped plate  794  of sliding support members  778 , for securement of wall panels  12  thereon. Then, each wall panel  12 , with its sliding support member  778  secured thereto, is slid in its base support  776  to the positions shown in  FIG. 37  toward each other until third walls  779   c  of J-shaped extension walls  779  engage within slots  12   d  of adjacent wall panels  12 . 
     Then, end extrusions  723  are assembled with the opposite sides of wall panels  12  such that third walls  727   c  of second J-shaped extension walls  727  engage within slots  12   d  at the opposite side edges of wall panels  12 . Thereafter, screws  750  are inserted through openings  748  in base sections  746  to secure end extrusions  723  in position. The construction then continues to the left and/or right in  FIG. 37  in the same manner. 
     In order to assemble wall panels  12  in covering relation to existing wall  14 , reference is made to  FIGS. 38-44  which utilizes the construction of the embodiment of  FIGS. 19-25 , with the understanding that this method is applicable to all of the above embodiments. 
     A first corner fastening extrusion  22   a - 1 ″ is first secured to existing wall  14 , as shown in  FIGS. 38 and 39 , by screws  50  through openings  48  thereof (or other fastening members such as double sided tape or the like) adjacent a corner where existing wall  14  meets another existing wall  14   a . In such case, wall  51   b ″ of first corner fastening extrusion  22   a - 1 ″ is positioned in abutting relation to adjacent existing wall  14   a . Then, a second corner fastening extrusion  22   a - 2 ″ is secured to existing wall  14 , as shown in  FIGS. 38 and 40 , by screws  50  through openings  48  thereof adjacent a corner where existing wall  14  meets a floor (or ceiling)  15 , and with an end edge of second corner fastening extrusion  22   a - 2 ″ abutting against the free edge  54 ″ of base section  46 ″ of first corner fastening extrusion  22   a - 1 ″ and with wall  51   b ″ of second corner fastening extrusion  22   a - 2 ″ positioned in abutting relation to floor  15 . 
     The base support  76  of one or more structural support assemblies  24  is secured to existing wall  14  in parallel, spaced relation to first corner fastening extrusion  22   a ″- 1 , with L-shaped retaining wall  86   a  being closer to corner fastening extrusion  22   a - 1 ″, and with one end edge of the base support  76  abutting against the free edge  54 ″ of base section  46 ″ of second corner fastening extrusion  22   a - 2 ″. 
     Thereafter, a sliding support member  78  is assembled with its base support  76  by angling sliding support member  78  slightly to slide wing  96   b  into the space  92  between the base plate  80  and second wall  90   b . At such time, the free end of wing  96   a  is positioned in spaced relation from the free edge of second wall  90   a , as shown in  FIGS. 38 and 41 , and in the manner shown in  FIG. 11 . In this position, sliding support member  78  is also offset in the lengthwise direction from its base support  76 , as shown in  FIG. 38 . Then, an adhesive member  98 , which can be a double sided tape, an adhesive or any other securing means, is secured on top of inverted U-shaped plate  94 . 
     The thin aluminum wall  18  of one wall panel  12  is then secured to the top of the inverted U-shaped plate  94  of at least one sliding support member  78  by the adhesive member  98 . In such position, the leftmost free edge of wall panel  12 , as viewed in  FIG. 42 , is in spaced relation to first corner fastening extrusion  22   a - 1 ″ and the lower edge of wall panel  12 , as viewed in  FIG. 42 , is in spaced relation to second corner fastening extrusion  22   a - 2 ″. 
     Thereafter, wall panel  12  is pushed to the left in the direction of arrow A and down in the direction of arrow B in  FIG. 43 , so that the left side edge of the wall panel  12  is in abutting relation with the respective bent end retaining wall  52 ″ of first corner fastening extrusion  22   a - 1 ″ and the lower edge of wall panel  12  is in abutting relation with the respective bent end retaining wall  52 ″ of second corner fastening extrusion  22   a - 2 ″. At the same time, sliding support member  78  is moved with wall panel  12  in the direction of arrow A to the left to the position shown in  FIG. 44  so that both wings  96   a  and  96   b  are positioned in spaces  92  and also downwardly in the direction of arrow B. 
     Then, in the manner shown in  FIGS. 2 and 4 , a main fastening extrusion  20 ″ ( FIGS. 20 and 21 ) has its leftmost retaining wall  32 ″ abutted up against the opposite end of the wall panel  12  such that this opposite free end of wall panel  12  seats on top of arcuate bend  37 ″ and beneath holding section  36 ″. Further, an end edge of this main fastening extrusion  20 ″ is abutted against the free edge  54 ″ of base section  46 ″ of second corner fastening extrusion  22   a - 2 ″. Screws  30  are then used to secure main fastening extrusion  20 ″ to existing wall  14 . This locks wall panel  12  tightly in position between first and second corner fastening extrusions  22   a - 1 ″ and  22   a - 2 ″ and main fastening extrusion  20 ″. 
     Thereafter, the base support  76  of one or more structural support assemblies  24  is secured to existing wall  14  in spaced relation from this main fastening extrusion  20 ″ with an end edge thereof abutted against the free edge  54 ″ of base section  46 ″ of second corner fastening extrusion  22   a - 2 ″. 
     At the opposite side of the already assembled main fastening extrusion  20 ″, a new wall panel  12  is assembled in the same manner as discussed above with respect to corner fastening extrusion  22   a - 1 ″, with a respective sliding support member  78  secured to this new wall panel  12  being slid over to the left in the direction of arrow A and downward in the direction of arrow B until the left side edge of the new wall panel  12  is in abutting relation with the other bent end retaining wall  32 ″ of the assembled main fastening extrusion  20 ″ and the lower edge of the new wall panel  12  is in abutting relation with the respective bent end retaining wall  52 ″ of second corner fastening extrusion  22   a - 2 ″. 
     This operation continues until the opposite corner wall  14   a  is reached, as shown in  FIG. 19 , at which time, a new corner fastening extrusion  22 ″ is assembled therewith. 
     Then, an elongated main fastening extrusion  20 ″ is assembled on wall  14  with the upper edges of the already assembled wall panels  12 , such that the upper edges of the already assembled wall panels  12  are in abutting relation to one retaining wall  32 ″ thereof and captured between the respective arcuate bend  37 ″ and holding section  36 ″. Then, the operation continues, on the opposite upper side of this new main fastening extrusion  20 ″ starting at the left side with corner fastening extrusion  22   a - 1 ″, in the manner discussed above, until the entire existing wall  14  is covered by wall panels  12 . 
     Closure members  60   a ″ are then assembled with all main fastening extrusions  20 ″ and corner fastening extrusions  22   a - 1 ″ and  22   a - 2 ″. 
     As a result, wall panels  12  are securely and tightly held in place without any play between main fastening extrusions  20  and corner fastening extrusions  22 , and locked in position. 
     Of course, it will be appreciated that the wall panels  12  can be removed by a reverse operation to that described above. 
     Referring now to  FIG. 45 , there is shown a system  810  which is a modification of the system  10 ″ of  FIGS. 19-25 , in which like parts are numbered with the same numerals but augmented by  800 . 
     Specifically, system  810  includes main fastening extrusions  820 , in which first and second base plate sections  826   a  and  826   b  thereof are each bent in an arcuate shape immediately adjacent the respective retaining wall  832   a  or  832   b  to form arcuate bends  837  that are bent in an arc towards the respective hold down wall  836 , in the same manner as described in  FIGS. 19-25 . 
     One retaining wall  832   b  of main fastening extrusions  820  is identical to that of retaining wall  32 ″ and is provided with a lower arcuate bend  833  that produces an outward bulge on the outwardly facing surface thereof and a recess on the inwardly facing surface thereof. In addition, retaining wall  832   b  is provided with an upper bulge  835  on the outwardly facing surface thereof immediately above lower arcuate bend  833 , and against which the edge of wall panels  12  abut. 
     Main fastening extrusion  820  differs from main fastening extrusion  20 ″ in that the other retaining wall  832   a , while including the lower arcuate bend  833 , has a height much greater height than retaining wall  832   b . Further, the upper end of retaining wall  832   a  is provided with an outwardly extending U-shaped holding wall  817  that engages the side edge and top and bottom surfaces of a wall panel  12 . In addition, an upper bulge  835  is provided within U-shaped holding wall  817  on the outwardly facing surface thereof and against which the end edge of a wall panel  12  abuts, for the same purpose as upper bulge  35 ″ in  FIG. 21 . 
     With the arrangement of  FIG. 45 , wall panels  12  can be provided at different heights to present an aesthetic three-dimensional effect. In other words, while wall panels  12   a  are raised from existing wall  14 , adjacent wall panels  12   b  can be mounted at a lower position, in the same manner as previously shown in  FIG. 14 . 
     In order to further support raised wall panels  12   a  and provide a spacing  851  between the wall panels  12  and the existing wall  14 , for example, for ventilation, to provide for water run-off, to provide insulation therein, and to provide a thermal barrier, a U-channel furring  852  is connected between existing wall  14  and the wall panels. 
     Specifically, U-channel furring  852  includes two parallel, spaced apart spacing walls  854  and  856  connected together by a common transverse connection wall  858  at one end of walls  854  and  856 , as is known. Also, outwardly extending foot walls  860  are connected to the opposite free ends of spaced apart walls  854  and  856 , as is also known. However, in accordance with one aspect of said U.S. patent application Ser. No. 15/047,024, opposing inwardly extending foot walls  861  extend inwardly of walls  854  and  856  in a coplanar arrangement with outwardly extending foot walls  860 , and opposite extension walls  862  are formed as a continuation of common transverse wall  858  and extend outwardly of spaced apart walls  854  and  856 . In this manner, insulation (not shown) can be positioned in spacing  851  so as to be tightly held between foot walls  860  and extension walls  862  so as to prevent escape thereof, and to keep the insulation properly positioned at all times. Further, the insulation is tightly held between common transverse wall  858  and inwardly extending foot walls  861 . This eliminates the need for any additional members to hold the insulation in place, such as screws, adhesives, etc., while also eliminating any extra labor that would result therefrom. 
     Outwardly extending foot walls  860  sit on top of first base plate section  826   a , and screws  850 , which secure base plate sections  826   a  and  826   b  to existing wall  14 , also secure foot walls  860  to base plate sections  826   a  and existing wall  14 . However, foot walls  860  can be positioned inside of first base plate sections  826   a.    
     Elongated base plate  880  of base support  876  of elongated intermediary structural support assembly  824 , which is identical to intermediary structural support assembly  24 , sits on top of common transverse wall  858  and includes openings  882  therein through which screws  884  extend to secure base plate  880  to common transverse wall  858 . Spaces  892  are provided at opposite sides of base support  876  in the same manner as previously discussed. Further, a sliding support member  878 , which is identical to sliding support member  78 , slidably fits within elongated base plate  880  in the same manner as previously discussed in relation to intermediary structural support assembly  24 , and includes an adhesive member  898 , which can be a double sided tape, an adhesive or any other securing means, secured on top of inverted U-shaped plate  894  of sliding support member  878 , for securement of wall panel  12  thereon. Wing plates  896   a  and  896   b  are provided at opposite sides of inverted U-shaped plate  894  in the same manner as described above. 
     With the above arrangement, in order to assemble wall panels  12  in covering relation to existing wall  14 , main fastening extrusions  820  and U-channel furrings  852  are secured to existing wall  14  as shown in  FIG. 45 , with the higher retaining walls  832   a  of adjacent fastening extrusions  820  positioned in parallel, spaced relation to the outside of spacing walls  854  and  856  of each U-channel furring  852 . The height of retaining walls  832   a  is slightly greater than the height of spacing walls  854  and  856 . Then, first wall panels  12   a  are secured on top of inverted U-shaped plate  894  of sliding support member  878  by an adhesive member  898 . The side edges of panel  12   a  are then slid into U-shaped holding walls  817  of adjacent main fastening extrusions  820 , while wing plates  896   a  and  896   b  are slid into spaces  892  of base support  876 , whereby a center section of panel  12   a  is stably supported on top of common transverse connection wall  858  of U-channel furring  852 . 
     Further, it will be appreciated that spacing walls  854  and  856  of a U-channel furrings  852  can have different heights, as shown at the right side of  FIG. 45 , for example, where spacing wall  854  is higher than spacing wall  856 . In this regard, the height of retaining wall  832   a  of the main fastening extrusion  820  adjacent spacing wall  854  would be greater than the height of retaining wall  832   a  of the main fastening extrusion  820  adjacent spacing wall  856 . Of course, outwardly extending U-shaped holding walls  817  would have to be angled slightly. This imparts a further three-dimensional inclined or slanted appearance to the wall panels  12 . 
     Thereafter, a closure member  860  which is identical to closure member  60   b ″ is provided, except that one side of closure member  860  is higher than the other side to accommodate the greater height retaining wall  832   a , and the upper ends of closure member  860  wrap around and snap over and onto U-shaped holding walls  817 . Closure member  860  is made of any suitable thin material such as aluminum. As a result, the gap between retaining walls  832   a  and  832   b  is covered. 
     Referring now to  FIG. 46 , there is shown a system  910  which is a modification of the system  10  of  FIGS. 1-4 , in which like parts are numbered with the same numerals but augmented by  900 . The differences in system  910  are as follows. 
     First, rather than using an adhesive member on top of inverted U-shaped plate  994  of sliding support member  978 , for securement of wall panel  12  thereon, the lower surface of wall panel  12  includes two spaced apart, parallel extending elongated dovetail shaped grooves  993  that receive two complementary spaced apart, parallel extending elongated dovetail shaped projections  995  extending from the upper surface of inverted U-shaped plate  994  of sliding support member  978 . 
     Second, in order to increase the thermal barrier between the existing wall  14  and the wall panels  12 , a non-thermal conducting or insulating, elongated spacer block  987  is provided between inverted U-shaped plate  994  of sliding support member  978  and elongated base plate  980  of base support  976 , preferably at the center thereof, and on which inverted U-shaped plate  994  of sliding support member  978  is slidably supported. Any suitable thermally insulating material can be used, for example, ethylene propylene diene monomer (EPDM), neoprene, polyisoprene, natural rubber, synthetic rubber sold under the trademark VITON, nitrile rubber, silicone, plastics or the like. It will be appreciated that the placement of elongated spacer block  987  and the positioning of inverted U-shaped plate  994  thereon, permits full sliding movement of inverted U-shaped plate  994  relative to base support  976 . In this regard, the upper surface of elongated spacer block  987  is provided with an elongated recess  979  for receiving the heads of screws  984  so that the heads of screws  984  do not extend higher than elongated spacer block  987 . 
     Third, openings  982  in elongated base plate  980  of base support  976  through which screws  984  extend to secure base plate  980  to existing wall  14 , have a diameter which is much greater than the diameter of screws  984  so that screws  984  are not in contact with base support  976 , and therefore, do not provide any thermal conduction to existing wall  14 . 
     It will be appreciated that system  910  can be used without elongated spacer block  987 , as shown in  FIG. 50 . 
     Further,  FIGS. 47-49  show modifications of the projections extending from the upper surface of inverted U-shaped plate  994  of sliding support member  978  of  FIG. 50 . Specifically, in place of the dovetail shaped projections  995  of  FIG. 50 , such projections can have any other suitable shape such as elongated diverging planar wall projections  995   a  shown in  FIG. 47 , elongated bulbous projections  995   b  shown in  FIG. 48 , elongated projections  995   c  having T-shaped cross-sections shown in  FIG. 49 , or any other suitable shaped projection. In addition, a double sided tape  981  can be provided at the underside of elongated base plate  980  of base support  976 , as shown in  FIG. 51 . 
     In the embodiments of  FIGS. 46-51 , it will be appreciated that the projections and recesses can be reversed such that the projections extend from wall panel  12  and the recesses are provided in inverted U-shaped plate  994 . 
     Referring now to  FIG. 52 , there is shown a modification of the arrangement of  FIG. 49  in which there is a stiffener element  991  which fixes the distance between adjacent base supports  976  and which provides further support for wall panels  12 . Specifically, stiffener element  991  includes a stiffener plate  991   a  having parallel, spaced apart separation walls  991   b  and  991   c  extending downwardly from the underside of stiffener plate  991   a  and against which first walls  988   a  and  988   b  of L-shaped retaining walls  986   a  and  986   b  abut, with ends of stiffener plate  991   a  resting on top of inwardly extending second walls  990   a  and  990   b  of L-shaped retaining walls  986   a  and  986   b . Stiffener element  991  also includes parallel, spaced apart limit walls  991   d  and  991   e  at a center portion thereof, with limit walls  991   d  and  991   e  being parallel to separation walls  991   b  and  991   c . In this manner, the ends of wall panels  12  seat upon stiffener plate  991   a  and abut against limit walls  991   d  and  991   e . The space between limit walls  991   d  and  991   e  can be left vacant, or can be closed by a plug or the like. 
     It will be appreciated that thermal break insulation members can be provided in association with the various elements discussed above in order to provide thermal insulation between wall panels  12  and existing wall  14  so as not to undesirably transfer heat and cold from the outside to existing wall  14 . Any suitable thermally insulating material can be used, for example, ethylene propylene diene monomer (EPDM), neoprene, polyisoprene, natural rubber, synthetic rubber sold under the trademark VITON, nitrile rubber, silicone, plastics or the like. 
     Thus, referring first to  FIG. 53 , J-shaped thermal insulation covers  266   a  can be provided, which are similar to J-shaped thermal insulation covers  266  of  FIG. 30 , the difference being that the lowest surfaces thereof are provided with elongated dovetail openings  293 , can be provided over outwardly extending put walls  260 , so as to sit on top of existing wall  14  to provide air and liquid channels therein or engage with corresponding elongated dovetail projections (not shown) in existing wall  14  or with further spacer elements. In like manner, the same J-shaped thermal insulation covers  266   a  can be inserted over opposite extension walls  262  of 
     U-channel furring  252  such that the elongated dovetail openings  293  face outwardly for receiving dovetail projections  290  of thermal break attachment  274  ( FIG. 30 ), for receiving dovetail projections (not shown) in elongated base plate  80  of a base support  76 , or for directly receiving elongated dovetail projections in wall panels  12 , that is a reversal apart from that shown by dovetail projections  995  in  FIG. 46 . 
     As shown in  FIG. 54 , a similar arrangement can be provided with Z-furring  1052 , which is similar to Z-furring  352  of  FIG. 31 . Z-furring  1052  includes a single spacing wall  1054 , with a transverse connection wall  1058  at an outer end thereof and extending to the right side of spacing wall  1054 , and an extension wall  1062  formed as a continuation of transverse wall  1058  and extending to the opposite left side of spacing wall  1054 . An outwardly extending transverse foot wall  1060  extends from the opposite end of spacing wall  1054  to the left side of spacing wall  1054 , and an inwardly extending transverse stub foot wall  1061  is also connected to the opposite free end of spacing wall  1054 , and extends to the right side of spacing wall  1054  in  FIG. 54 . In this manner, insulation  1073  is tightly held between foot wall  1060  and extension wall  1062  so as to prevent escape thereof, and to keep insulation properly positioned at all times. Further, insulation is tightly held between transverse wall  1058  and inwardly extending stub foot wall  1061 . This eliminates the need for any additional members to hold the insulation in place, such as screws, adhesives, etc., while also eliminating any extra labor that would result therefrom. 
     A J-shaped thermal insulation cover  1066   a  can be provided around foot wall  1060 , and which is the same as J-shaped thermal insulation cover  266   a  of  FIG. 53 . Screws  1050  extend through J-shaped thermal insulation cover  266   a  and foot wall  1060 , into an existing wall  1014 . 
     A rod  1059  extends upwardly from the outer end of Z-furring  1052 . A panel, bricks or the like  1012  is positioned over transverse connection wall  1058  and extension wall  1062 , as well as over insulation  1073 , with rod  1059  extending through an opening  1013  in panel, bricks or the like  1012 , and a cement or adhesive  1015  provided in opening  1013  in order to secure panel, bricks or the like  1012  thereat. 
       FIG. 55  shows an arrangement similar to that of  FIGS. 19-21 , but in which J-shaped thermal insulation covers  66   a ″ are provided in covering relation to base section  26 ″ extending to the outside of arcuate bends  37 ″. Screws  30  extend through J-shaped thermal insulation covers  66   a ″ as well as through base section  26 ″. Preferably, the inner ends of downturned walls  60   b   1 ″ of closure member  60   b ″, as best shown in  FIG. 55A , have inwardly directed tabs or beads  60   b   2 ″ that engage within cut-away recesses  36   a ″ at the free ends of enlarged holding section  36 ″. 
     In addition, an elongated spacer block  87 ″ is provided on top of base section  26 ″ between retaining walls  32 ″. Any suitable thermally insulating material can be used, for example, ethylene propylene diene monomer (EPDM), neoprene, polyisoprene, natural rubber, synthetic rubber sold under the trademark VITON, nitrile rubber, silicone, plastics or the like. The upper surface of elongated spacer block  87 ″ is provided with spaced apart openings  79 ″ for receiving the heads of screws  30  so that the heads of screws  30  do not extend higher than elongated spacer block  87 ″. The outwardly extending side walls  87   a ″ of elongated spacer block  87 ″ on opposite sides of openings  79 ″ are provided with inwardly turned catches  87   b ″ at the upper ends thereof. 
     A closure member  60   b ″ is provided in the gap between retaining walls  32 ″, and like closure member  60   a ″, includes a U-shaped center section  65   b ″ and L-shaped cover walls  62   b ″. However, in addition, closure member  60   b ″ also includes two parallel, spaced apart walls  69   b ″ extending from the underside of U-shaped center section  65   b ″, with the lower ends of walls  69   b ″ including outwardly extending tabs  67   b ″ for engaging with catches  87   b ″. With this arrangement, when closure member  60   b ″ is snapped into position, tabs  67   b ″ force catches  87   b ″ outwardly. Because catches  87   b ″ are positioned adjacent recesses  33   b ″, this enables catches  87   b ″ to be biased outwardly into recesses  33   b ″, whereupon they snap back to their original position once tabs  67   b ″ pass catches  87   b″.    
     In addition, thin walled J-shaped thermal insulation covers  66   b ″ are provided in surrounding relation to the ends of wall panels  12 , and fit with the ends of wall panels  12  into the space between holding sections  36 ″ and arcuate bends  37 ″. The inner surfaces of thin walled J-shaped thermal insulation covers  66   b ″ against which the end edges of wall panels  12  abut, each include an elongated bead  35   b ″ that serves the same function as upper bulge  35 ″ in  FIGS. 19-21 . 
       FIG. 56  shows a closure member  60   c ″ which is similar to closure member  60   b ″ of  FIG. 55 , but with the difference being that spaced apart walls  69   b ″ extend to the outside of side walls  87   a ″ of elongated spacer block  87 ″, with catches  87   b ″ outwardly extending and tabs  67   b ″ inwardly extending. In this manner, tabs  67   b ″ are biased outwardly into recesses  33   b ″ by catches  87   b ″. In other words, it is a reversal of parts from the arrangement of  FIG. 55 . 
       FIG. 57  shows a closure member  60   d ″ which is a modification of closure member  60   a ″. Specifically, tabs  67   b ″ are replaced by outwardly extending, flexible catch walls  67   d ″ connected at their lower ends to lower ends of spaced apart walls  69   d ″. When U-shaped center section  65   c ″ and apart walls  69   d ″ are inserted into the space between retaining walls  32 ″, flexible catch walls  67   d ″ are bent back against spaced apart walls  69   d ″ until the upper free ends of flexible catch walls  67   d ″ pass recesses  33   b ″, whereupon flexible catch walls  67   d ″ spring outwardly back to their original positions such that the upper free ends of flexible catch walls  67   d ″ are captured within recesses  33   b ″ to lock closure member  60   d ″ in position, with L-shaped cover walls  62   d ″ in covering relation to hold down walls  36 ″. 
       FIG. 58  shows a closure member  60   e ″ which is a modification of closure member  60   d ″. Specifically, spaced apart walls  69   e ″ are of a much smaller length than spaced apart walls  69   d ″, and therefore do not extend down below recesses  33   b ″. Flexible catch walls  67   e ″ are also of a much smaller length than flexible catch walls  67   d″.    
       FIG. 59  shows a closure member  60   f ″ which is a modification of closure member  60   e ″. Specifically, spaced apart side walls of U-shaped center section  65   f ″ are spaced closer together than the corresponding spaced apart side walls of U-shaped center section  65   e ″ of closure member  60   e ″, and spaced apart walls  69   f ″ are connected to the lower ends of the side walls of U-shaped center section  65   f ″ by transverse walls  71   f″.    
     Referring now to  FIG. 60 , there is shown a modification of closure member  60   a ″ of  FIG. 19  in which the ends of L-shaped cover walls  62   a ″ are provided with inwardly directed beads  62   e ″ which snap into and engage within elongated recesses  41 ″ in end edges of enlarged holding sections  36 ″. In such case, tabs  67   a ″ can be eliminated. 
     Referring now to  FIGS. 61 and 62 , there is shown a further embodiment for attaching wall panels  12  to existing wall  14 . Specifically, wall panels  12  are provided with elongated dovetail shaped grooves  1193 , similar to dovetail shaped grooves  993 . 
     Elongated, generally U-shaped sliding support members  1178  are provided, each including two spaced apart, parallel walls  1178   a  and  1178   b  which are connected at common edges thereof to a connecting plate  1178   c  so as to define an open area  1178   d  therebetween, which is accessible from the opposite ends of walls  1178   a  and  1178   b . An elongated dovetail shaped projection  1195  is formed at the outer surface of wall  1178   b , and is received within a corresponding dovetail shaped groove  1193  in order to secure wall panels  12  to sliding support members  1178 . 
     A base support  1176  is secured to existing wall  14  by screws  1184 . Specifically, base support  1176  includes an elongated trapezoidal shaped base section  1176   a  formed by a first elongated wall  1176   b  positioned in parallel, spaced relation to existing wall  14  with a space  1177  therebetween, a first elongated supporting wall  1176   c  extending from one side of elongated wall  1176   b  into contact with existing wall  14 , and a second elongated supporting wall  1176   d  extending at an outward angle from the opposite side of first elongated wall  1176   b  into contact with existing wall  14 . An elongated tail wall  1176   e  is connected with the free edge of second elongated supporting wall  1176   d  and extends away from trapezoidal shaped base section  1176   a , so as to be in flush contact with existing wall  14 . Tail wall  1176   e  has a plurality of spaced apart openings  1176   f  therein through which screws  1184  can extend into existing wall  14  in order to secure base support  1176  thereto. 
     Base support  1176  further includes a generally L-shaped retaining wall  1186 . Specifically, L-shaped retaining wall  1186  includes a first elongated wall  1188  that extends at an angle of about 45° from the upper and of first elongated supporting wall  1176   b  and an inwardly extending elongated second wall  1190  connected to the free end of first elongated wall  1188  such that elongated second wall  1190  is positioned above first elongated wall  1176   b  in parallel, spaced apart relation so as to define an open area  1192  therebetween. 
     In this manner, with a sliding support member  1178  connected by the dovetail connection to a wall panel  12 , wall  1178   a  is inserted within open area  1192  so as to be captured therein. In such condition, inwardly extending elongated second wall  1190  extends into open area  1178   d . Thereafter, the next wall panel  12  is assembled in the same manner adjacent to the previous wall panel  12 , with abutting edges thereof so that the second wall panel  12  locks the first wall panel  12  into the position shown. Alternatively, the arrangement of  FIGS. 1 and 19  can be used to lock the opposite and of the wall panel. 
     It will be appreciated that base support  1176  can be made of a thermally insulating material of the type previously discussed in order to thermally insulate existing wall  14  with respect to wall panels  12 . Alternatively, base support  1176  can be made of any other suitable material, such as aluminum or the like. 
     As a further modification, as shown in  FIG. 63 , base support  176  can be secured instead on a U-channel furring  1152  of the type shown in  FIG. 53  in order to provide further separation of wall panels  12  from existing wall  14 .  FIGS. 64 and 65  show further modifications of  FIGS. 62 and 63 , respectively, in which dovetail shaped grooves  1193  are eliminated, and in place thereof, there are elongated T-shaped openings  1193   a  in polyethylene core  16  and the thin aluminum wall  18  covering the inner surface thereof. In place of dovetail shaped projections  1195 , T-shaped projections  1195   a  extend from the outer surface of wall  1178   b  for sliding reception within T-shaped openings  1193   a.    
     Alternatively, as shown in  FIGS. 66 and 67 , which show further modifications of  FIGS. 62 and 63 , respectively, dovetail shaped grooves  1193  are eliminated, and in place thereof, there are elongated bulbous shaped openings  1193   b  in polyethylene core  16  and the thin aluminum wall  18  covering the inner surface thereof. In place of dovetail shaped projections  1195 , elongated bulbous projections  1195   b  extend from the outer surface of wall  1178   b  for sliding reception within bulbous openings  1193   b.    
       FIGS. 68 and 69  show further modifications of  FIGS. 62 and 63 , respectively, in which dovetail shaped grooves  1193  and dovetail shaped projections  1195  are eliminated, and in place thereof, a double sided adhesive strip  1195   c  is positioned between the outer surface of wall  1178   b  and the inner surface of wall panel  12  to secure the same together. 
       FIG. 70  shows a further modification in which wall  1178   b  is extended to the opposite side of connecting plate  1178   c  to form a tail wall  1178   e  which is connected to wall panel by screws  1184   a.    
     It will be appreciated that some or all elements of all of the above discussed structural connections can be made of a thermally insulating material. 
     Having described specific preferred embodiments of the invention with reference to the accompanying drawings, it will be appreciated that the present invention is not limited to those precise embodiments and that various changes and modifications can be effected therein by one of ordinary skill in the art without departing from the scope or spirit of the invention as defined by the appended claims.