Patent Publication Number: US-7712273-B2

Title: Thermal breaker structures for use with roof decking assemblies

Description:
FIELD OF THE INVENTION 
   The present invention relates generally to thermal breaker or thermal barrier structures, and more particularly to new and improved thermal breaker or thermal barrier structures for use in connection with roof decking assemblies for effectively preventing the respective transmission of heating gradients from the interior or exterior building environment to the exterior or interior building environment by thermal conductivity so as to render the building more energy efficient. While the thermal breaker or thermal barrier structure of the present invention will be described in connection with roof decking assemblies, it is to be appreciated that the attributes of the thermal breaker or thermal barrier of the present invention can likewise be applicable to other controlled environment structures and the component parts thereof, such as, for example, automobiles, airplanes, refrigerators, freezers, windows, walls, computers and other electronic components, and the like. 
   BACKGROUND OF THE INVENTION 
   Steel fasteners, clips, and other means, used for securing external structural component parts to internal component parts wherein the external structural component parts are exposed to hot or cold weather conditions, allow heat to escape from the thermally heated interior region of, for example, a building or dwelling, or alternatively, allow heat to effectively invade the thermally cooled or air-conditioned interior region of the building or dwelling, by thermal conductivity. For example, a conventional PRIOR ART clip and tab assembly, for fixedly securing roofing panels to an underlying roofing substructure, is disclosed within  FIG. 1  and is generally indicated by the reference character  10 . More particularly, it is seen that the conventional PRIOR ART clip and tab assembly  10  comprises a substantially L-shaped clip  12  comprising a vertically oriented long leg component  14  and a horizontally oriented short leg component  16 . The horizontally oriented short leg component  16  is adapted to be seated upon and fixedly connected to a joist member of the underlying roofing substructure by means of, for example, screw fasteners, while the upper end portion of the vertically oriented long leg component  14  is provided with a pair of laterally spaced lugs  18 , 18  bent at an angle of substantially 90° with respect to the vertically oriented long leg component  14  so as to be disposed substantially parallel to the horizontally oriented short leg component  16 , and a centrally located lug  20  which is also bent at an angle of substantially 90° with respect to the vertically oriented long leg component  14 , so as to likewise be disposed substantially parallel to the horizontally oriented short leg component  16 , the lugs  18 ,  20  extending in opposite directions. Taken together, the lugs  18 , 20  effectively define shelf, ledge, or support surfaces upon which mating crest portions of adjacent roofing panels, forming the roof decking, are adapted to be respectively seated. 
   A tab member  22  is fixedly mounted upon the vertically oriented long leg component  14  of the clip  12  by means of a dimpled detent  24  or the like for permitting the tab member  22  to be retained at the central position upon the clip  12  but nevertheless movable toward the left or right as viewed in the drawing figure, while the horizontally oriented leg component  16  of the clip  12  is adapted to be fixedly connected to a joist member, not shown, of an underlying roofing substructure. The upper end portion of the tab member  22  is provided with a substantially arcuate portion  26  which is adapted to internally accommodate an upstanding portion of one of the mating adjacent roofing panels while the upstanding portion of the other one of the mating adjacent roofing panels is adapted to be disposed upon the external surface region of the arcuate portion  26  of the tab member  22  such that the two upstanding portions of the mating adjacent roofing panels form with the arcuate portion  26  of the tab member  22  a three-piece sandwich or laminated structure. In this manner, when such sandwich or laminated structure, comprising the pair of upstanding portions of the mating adjacent roofing panels and the arcuate portion  26  of the tab member  22 , is subsequently rolled and crimped, the mating adjacent roofing panels are fixedly secured to the joist member of the underlying roofing substructure through means of the clip and tab assembly  10 . An outwardly projecting portion  28  of the tab member  22 , disposed within the slot  30  of the vertical leg  14  of the clip  12  permits the tab member  22 , and the adjacent roofing panels connected thereto, to undergo lateral movement in accordance with expansion and contraction conditions attendant the roofing panels. With the aforenoted clip and tab assembly  10 , it can readily be appreciated, however, that a thermal flow path is directly established or defined between the joist member, which is disposed internally within the building structure, and the roofing panels which are disposed externally of the building structure through means of the clip  12  and the tab member  22 , as well as the screws securing the clip  12  to the underlying joist member. Accordingly, heat from the heated environment disposed or contained internally within the building structure can effectively escape to the outside cold weather environment, or alternatively, heat from the outside hot weather environment can effectively invade the cooled or air-conditioned environment disposed or contained internally within the building structure. A need therefore existed in the art for effectively breaking or interrupting the aforenoted thermal flow path so as to terminate or prevent the egress or ingress of the heat or thermal energy out from or into the building structure. 
   Accordingly, the thermal breaker or thermal barrier assembly, as disclosed within  FIG. 2  and generally indicated by the reference character  110 , was developed in an attempt to address and resolve the aforenoted problems or deficiencies characteristic of the clip and tab assembly  10  disclosed within  FIG. 1 . More particularly, the thermal breaker or thermal barrier assembly  110  is seen to comprise a thermal breaker or thermal barrier member  112  which is fabricated from a suitable plastic material by means of an injection molding process, and it is seen that the thermal breaker or thermal barrier member  112  comprises a horizontally disposed lower base portion  114  and an upper domed portion  116 . The lower base portion  114  is adapted to be seated upon and secured to a joist member  118  of the underlying roofing substructure, and the upper domed portion  116  is seen to have a substantially diamond-shaped cross-sectional configuration. More particularly, it is seen that the upper domed portion  116  has oppositely disposed inclined surface regions  120 , 122 , as well as an upper substantially planar surface region  124  which is disposed substantially parallel to the horizontally oriented lower base portion  114 . 
   In this manner, side edge portions of a pair of adjacent roofing panels  126 , 128  can be supported upon the oppositely disposed inclined surface regions  120 , 122 , as well as upon the upper substantially planar surface region  124 , of the thermal breaker or thermal barrier member  112  so as to be mated and connected together. The central region of the upper domed portion  116  of the thermal breaker or thermal barrier member  112  is provided with a slot  130  having a substantially inverted T-shaped cross-sectional configuration, and a clip  132 , having a substantially T-shaped cross-sectional configuration, is disposed in an inverted mode such that the head portion  134  of the clip  132  is disposed internally within the transverse portion of the slot  130  while the opposite free end portion  136  of the clip  132  projects outwardly from the thermal breaker or thermal barrier member  112  so as to be operatively crimped together with the side edge portions of the pair of adjacent roofing panels  126 , 128 , thereby fixedly securing the pair of adjacent roofing panels  126 , 128  to the joist member  118  of the underlying substructure. 
   While the aforenoted thermal breaker or thermal barrier  110  ostensibly appears to resolve the problems noted hereinbefore with respect to the conventional PRIOR ART clip and tab assembly  10  as disclosed within  FIG. 1 , in that a thermal breaker or thermal barrier is in fact effectively interposed between the joist member  118  and the pair of mated roofing panels  126 , 128 , the thermal breaker or thermal barrier assembly  110  nevertheless still poses or exhibits some undesirable operational and fabrication characteristics. For example, since the thermal breaker or thermal barrier member  112  is fabricated by injection molding techniques, and since the volume encompassed by means of the thermal breaker or thermal barrier member  112  is substantial, in that the thermal breaker or thermal barrier member  112  has a length dimension of eight inches (8.00″) and a height dimension of two inches (2.00″), the thermal breaker or thermal barrier member  112  is costly to manufacture due to material costs and injection molding cycle time. In addition, even though the thermal breaker or thermal barrier member  112  is in fact fabricated from a suitable plastic material, it is noted that a predetermined axially located region of the thermal breaker or thermal barrier member  112  has its complete undersurface portion of the base portion  114  disposed in contact with the underlying joist member  118 , while the upper domed region  116  of the thermal breaker or thermal barrier member  112  has its inclined surface portions  120 , 122 , and its upper planar portion  124 , disposed in complete surface contact with the pair of mated adjacent roofing panels  126 , 128 . 
   Accordingly, since the roofing panels  126 , 128  are exposed, for example, to cold external atmospheric air, while the joist member  118  is exposed to an internally heated environment, or alternatively, since the roofing panels  126 , 128  are exposed, for example, to hot external atmospheric air, while the joist member  118  is exposed to an internally cooled or air-conditioned environment, the thermal path extending between the interior of the building structure and the external atmospheric environment remains intact whereby heat loss or egress of thermal energy out from the interior of the building structure, or the ingress of thermal energy into the building structure, can effectively continue at an undesirable rate. Still yet further, it is noted that the clip  132  is fabricated as a single sheet member which is effectively folded in a predetermined manner, and along predetermined fold lines, so as to effectively form the final clip structure. It is noted, however, that the folded and mated regions of the clip are not in fact fixedly secured with respect to each other. Accordingly, wind uplift forces can cause the clip  132  to fail in view of the fact that the wind uplift forces will not be evenly impressed upon or evenly distributed throughout the various sections or regions of the clip  132 . 
   A need therefore exists in the art for a new and improved thermal breaker or thermal barrier assembly which is capable of being manufactured in a cost-effective manner, which effectively rectifies the deficiencies characteristic of the conventional PRIOR ART thermal breaker or thermal barrier structures so as to in fact significantly reduce the amount of heat loss or egress of thermal energy out from the interior of the building structure, or the ingress of thermal energy into the building structure, and which comprises a clip member, for effectively connecting together the edge portions of the adjacent roofing panels, which is rigidified in a predetermined manner so as to effectively reinforce itself and thereby be capable of resisting wind uplift forces such that the clip member does not exhibit failure under wind uplift force conditions. 
   SUMMARY OF THE INVENTION 
   The foregoing and other objectives are achieved in accordance with the teachings and principles of the present invention through the provision of a new and improved thermal breaker or thermal barrier assembly which comprises a new and improved thermal breaker or thermal barrier member which is fabricated from a suitable plastic material by means of a suitable pulltrusion, injection molding, machining, or extrusion process. In addition, the thermal breaker or thermal barrier member is provided with a plurality of axially extending voids or passageways, which are distributed throughout the thermal breaker or thermal barrier member in a predetermined symmetrical arrangement or array, wherein not only do such voids or passageways effectively provide thermal insulation characteristics, but in addition, such voids or passageways eliminate a substantial volume of the plastic material required to fabricate the thermal breaker or thermal barrier member so as to render the same more economical or cost-effective to produce. Still further, the presence of such axially extending voids or passageways, within such predetermined symmetrical array or arrangement, provides the thermal breaker or thermal barrier member with a plurality of vertically and horizontally oriented, reinforcing structural rib members. Still yet further, all of the external surface portions of the thermal breaker or thermal barrier member, that are disposed in contact with the pair of adjacent roofing panels, as well as with the underlying joist member, are discontinuous such that the locations at which the pair of adjacent roofing panels, or at which the underlying joist member, are disposed in contact with the thermal breaker or thermal barrier, comprise point loci or linear loci. 
   In this manner, the overall surface-to-surface contact defined between the edge portions of the pair of adjacent roofing panels and the external surface portions of thermal breaker or thermal barrier member upon which the edge portions of the pair of adjacent roofing panels are seated, as well as between the external undersurface region of the base portion of the thermal breaker or thermal barrier and the underlying joist member upon which the base portion of the thermal barrier or thermal breaker member is seated, is effectively minimized. Accordingly, the thermal path extending between the interior of the building structure and the external atmospheric environment is effectively broken and is no longer intact, whereby heat loss or egress of thermal energy out from the interior of the building structure, or the ingress of thermal energy into the building structure, is significantly reduced. Still further, the fabrication of the clip member is such that portions of a first folded and mating ply of the clip member are fixedly secured to corresponding portions of the second folded and mating ply of the clip member whereby the mated portions of the clip member cannot in fact separate with respect to each other under, for example, wind uplift forces, whereby the clip member will exhibit significant wind uplift force resistance and will not exhibit failure under wind uplift conditions. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Various other features and attendant advantages of the present invention will be more fully appreciated from the following detailed description when considered in connection with the accompanying drawings in which like reference characters designate like or corresponding parts throughout the several views, and wherein: 
       FIG. 1  is a perspective view of a conventional PRIOR ART clip and tab assembly used for fixedly connecting mating edge portions of adjacent roofing panels to underlying joist members of a roof decking substructure; 
       FIG. 2  is a perspective view of a conventional PRIOR ART thermal breaker or thermal barrier assembly which includes therein a clip and tab assembly for fixedly connecting mating edge portions of adjacent roofing panels to underlying joist members of a roof decking substructure; 
       FIG. 3  is a perspective view of a first embodiment of a new and improved thermal breaker or thermal barrier assembly which has been constructed in accordance with the principles and teachings of the present invention, and which shows the cooperative parts thereof, for fixedly connecting mating edge portions of adjacent roofing panels to underlying joist members of a roof decking substructure; 
       FIG. 4  is a perspective view of the clip, mounted within the thermal breaker or thermal barrier member disclosed within  FIG. 3 , which is effectively used to crimpingly secure together the side edge portions of the adjacent roofing panels, thereby effectively securing the roofing panels to the underlying joist member through means of the thermal breaker or thermal barrier member; 
       FIG. 5  is a perspective view of a second embodiment of a new and improved thermal breaker or thermal barrier assembly which has been constructed in accordance with the principles and teachings of the present invention, and which shows the cooperative parts thereof, for fixedly connecting mating edge portions of adjacent roofing panels to underlying joist members of a roof decking substructure; 
       FIG. 6  is a perspective view of a third embodiment of a new and improved thermal breaker or thermal barrier assembly which has been constructed in accordance with the principles and teachings of the present invention, and which shows the cooperative parts thereof, for fixedly connecting mating edge portions of adjacent roofing panels to underlying joist members of a roof decking substructure; 
       FIG. 7  is a perspective view of a fourth embodiment of a new and improved thermal breaker or thermal barrier assembly which has been constructed in accordance with the principles and teachings of the present invention, and which shows the cooperative parts thereof, for fixedly connecting mating edge portions of adjacent roofing panels to underlying joist members of a roof decking substructure; 
       FIG. 8  is a perspective view of a fifth embodiment of a new and improved thermal breaker or thermal barrier assembly which has been constructed in accordance with the principles and teachings of the present invention, and which shows the cooperative parts thereof, for fixedly connecting mating edge portions of adjacent roofing panels to underlying joist members of a roof decking substructure; 
       FIG. 8   a  is an enlarged detail view of the sleeve member incorporated within the thermal breaker or thermal barrier assembly of  FIG. 8 ; 
       FIG. 9  is a perspective view of a sixth embodiment of a new and improved thermal breaker or thermal barrier assembly which has been constructed in accordance with the principles and teachings of the present invention, and which shows the cooperative parts thereof, for fixedly connecting mating edge portions of adjacent roofing panels to underlying joist members of a roof decking substructure; 
       FIG. 10  is a perspective view of a seventh embodiment of a new and improved thermal breaker or thermal barrier assembly which has been constructed in accordance with the principles and teachings of the present invention, and which shows the cooperative parts thereof, for fixedly connecting mating edge portions of adjacent roofing panels to underlying joist members of a roof decking substructure; 
       FIG. 11  is a perspective view of an eighth embodiment of a new and improved thermal breaker or thermal barrier assembly which has been constructed in accordance with the principles and teachings of the present invention, and which shows the cooperative parts thereof, for fixedly connecting mating edge portions of adjacent roofing panels to underlying joist members of a roof decking substructure; 
       FIG. 12  is a schematic plan view of a second embodiment of wavy or sinusoidal structure which may effectively be incorporated onto any of the external surface regions of the thermal barrier or thermal breaker member, in lieu of the axially oriented rib members as disclosed within  FIG. 3 , so as to minimize the surface contact area and thereby render the thermal breaker or thermal barrier assembly more thermally efficient; 
       FIG. 13  is a side elevational view of a third embodiment of projection structure which may effectively be incorporated onto the external inclined surface regions and the upper planar region, as well as upon the undersurface region of the lower base portion, of the domed portion of the thermal barrier or thermal breaker in, lieu of the axially oriented rib members as disclosed within  FIG. 3 , so as to minimize the surface contact area; 
       FIG. 14  is a schematic plan view of a fourth embodiment of orange rind structure which may effectively be incorporated onto any of the external surface regions of the thermal barrier or thermal breaker member, in lieu of the axially oriented rib members as disclosed within  FIG. 3 , so as to minimize the surface contact area and thereby render the thermal breaker or thermal barrier assembly more thermally efficient; 
       FIG. 15  is a schematic plan view of a fifth embodiment of coarse finish structure which may effectively be incorporated onto any of the external surface regions of the thermal barrier or thermal breaker member, in lieu of the axially oriented rib members as disclosed within  FIG. 3 , so as to minimize the surface contact area and thereby render the thermal breaker or thermal barrier assembly more thermally efficient; 
       FIG. 16  is a schematic side elevational view of a sixth embodiment of bump structure which may effectively be incorporated onto any of the external surface regions of the thermal barrier or thermal breaker member, in lieu of the axially oriented rib members as disclosed within  FIG. 3 , so as to minimize the surface contact area and thereby render the thermal breaker or thermal barrier assembly more thermally efficient; 
       FIG. 17  is a schematic side elevational view of a seventh embodiment of stand-off structure which may effectively be incorporated onto any of the external surface regions of the thermal barrier or thermal breaker member, in lieu of the axially oriented rib members as disclosed within FIG.  3 , so as to minimize the surface contact area and thereby render the thermal breaker or thermal barrier assembly more thermally efficient; 
       FIG. 18  is a schematic side elevational view of an eighth embodiment of dimpled structure which may effectively be incorporated onto any of the external surface regions of the thermal barrier or thermal breaker member, in lieu of the axially oriented rib members as disclosed within  FIG. 3 , so as to minimize the surface contact area and thereby render the thermal breaker or thermal barrier assembly more thermally efficient; and 
       FIG. 19  is a schematic side elevational view of a ninth embodiment of air bubble structure which may effectively be incorporated internally within the thermal barrier or thermal breaker, in lieu of, or in addition to, the axially oriented rib members as disclosed within  FIG. 3 , so as to minimize thermal gradient transmissions and thereby render the thermal breaker or thermal barrier assembly more thermally efficient. 
   

   DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS 
   Referring now to the drawings, and more particularly to  FIG. 3  thereof, a first embodiment of a new and improved thermal breaker or thermal barrier assembly, which has been constructed in accordance with the principles and teachings of the present invention, and which shows the cooperative parts thereof, for fixedly connecting mating edge portions of adjacent roofing panels to underlying joist members of a roof decking substructure, is disclosed and is generally indicated by the reference character  210 . More particularly, the thermal breaker or thermal barrier assembly  210  is seen to comprise a thermal breaker or thermal barrier member  212  which is fabricated from a suitable plastic material by means of a pulltrusion process, wherein, for example, the plastic material comprises a thermoset polyvinylester crosslinked material. It is seen that the thermal breaker or thermal barrier member  212  comprises a horizontally disposed lower base portion  214  and an upper domed portion  216 . The lower base portion  214  is adapted to be seated upon and secured to a joist member, not illustrated but similar to the joist member  118  illustrated within  FIG. 2 , of an underlying roofing substructure by means of, for example, a pair of headed bolt fasteners  218 , and the upper domed portion  216  is seen to have a substantially diamond-shaped cross-sectional configuration. More particularly, it is seen that the upper domed portion  216  has oppositely disposed inclined surface regions  220 , 222 , as well as an upper substantially planar surface region  224  which is disposed substantially parallel to the horizontally oriented lower base portion  214 . 
   In this manner, side edge portions of a pair of adjacent roofing panels, also not illustrated but similar to the roofing panels  126 , 128  illustrated within  FIG. 2 , can be supported upon the oppositely disposed inclined external surface regions  220 , 222 , as well as upon the upper substantially planar surface region  224 , of the thermal breaker or thermal barrier member  212  so as to be mated and connected together by means of a clip  226  in a manner similar to that achieved by means of the clip  132  illustrated within  FIG. 2 . The central region of the upper domed portion  216  of the thermal breaker or thermal barrier member  212  is provided with a slot  228  having a substantially inverted T-shaped cross-sectional configuration, and it is seen that the clip  226 , also having a substantially T-shaped cross-sectional configuration, is disposed in an inverted mode such that the head portion  230  of the clip  226  is disposed internally within the transverse portion  232  of the slot  228  while the opposite free end portion  234  of the clip  226  projects outwardly from the thermal breaker or thermal barrier member  212  so as to form a tab which can be operatively crimped together with the side edge portions of the pair of adjacent roofing panels, in a manner illustrated within  FIG. 2 , thereby fixedly securing the pair of adjacent roofing panels to the joist member of the underlying substructure. 
   In connection with the mounting or disposition of the pair of headed bolt fasteners  218 , 218  within the lower base portion  214  of the thermal barrier or thermal breaker member  212 , a pair of vertically oriented bores  236 , 236  pass through the thermal breaker or thermal barrier member  212  so as to permit the pair of headed bolt fasteners  218 , 218  to be inserted into the thermal breaker or thermal barrier member  212 . It is noted that the upper regions of the bores  236 , 236 , as well as sections, not shown, of the head portion  230  of the clip  226 , are effectively cut out and counterbored so as to permit the head portions  238 , 238  of the headed bolt fasteners  218 ,  218  to pass therethrough, however, the lower regions of the bores  236 , 236  are not counterbored so as to permit or cause the head portions  238 , 238  of the headed bolt fasteners  218 ,  218  to be seated, in effect, atop the lower base portion  214  of the thermal breaker or thermal barrier member  212 . 
   In accordance with several additional unique and novel features characteristic of the new and improved thermal breaker or thermal barrier assembly  210  of the present invention, in order to render the same more thermally efficient, or, in other words, to effectively prevent thermal heat loss, it is seen that, as can be further appreciated from  FIG. 3 , each one of the oppositely disposed inclined external surface regions  220 , 222  of the thermal breaker or thermal barrier member  212  is integrally provided with a plurality of axially extending rib members  240 . In a similar manner, it is seen that the upper planar surface region  224  of the thermal barrier or thermal breaker member  212  is likewise provided with a plurality of axially extending rib members  242 , and still further, the undersurface region of the lower base portion  214  of the thermal breaker or thermal barrier member  212  is also provided with a plurality of axially extending rib members  244 . In this manner, in lieu of the side edge portions of the pair of adjacent roofing panels, not illustrated but similar to the roofing panels  126 , 128  illustrated within  FIG. 2 , being respectively supported upon the oppositely disposed inclined external surface regions  220 , 222  of the thermal breaker or thermal barrier member  212 , as well as upon the upper planar surface region  224  of the thermal barrier or thermal breaker  212 , in a substantially surface-to-surface contact mode, the side edge portions of the pair of adjacent roofing panels will be respectively supported upon the oppositely disposed inclined external surface regions  220 , 222  of the thermal breaker or thermal barrier member  212 , as well as upon the upper planar surface region  224  of the thermal barrier or thermal breaker member  212 , along linear loci defined by means of each one of the axially rib members  240 , 242 . This arrangement for supporting the pair of adjacent roofing panels upon the oppositely disposed inclined external surface regions  220 , 222  of the thermal breaker or thermal barrier member  212 , as well as upon the upper planar surface region  224  of the thermal breaker or thermal barrier member  212 , therefore significantly reduces the contact area defined between the pair of adjacent roofing panels and the oppositely disposed inclined external surface regions  220 , 222  of the thermal barrier or thermal breaker member  212 , as well as between the pair of adjacent roofing panels and the upper planar surface region  224  of the thermal breaker or thermal barrier member  212 , so as to militate against the transmission of thermal gradients across such structural interfaces. A similar reduction in the transmission of thermal gradients across the interface defined between the lower base portion of the thermal breaker or thermal barrier member  212  and the underlying joist member, similar to the joist member  118  as illustrated within  FIG. 2 , is likewise achieved by means of the plurality of axially extending rib members  244  provided upon the underlying exterior surface of the lower base portion  214  of the thermal breaker or thermal barrier member  212 . 
   With reference still being made to  FIG. 3 , another unique and novel structural feature, characteristic of the new and improved thermal breaker or thermal barrier assembly  210  of the present invention, resides in the provision or formation of a plurality of axially extending voids or passageways within the thermal breaker or thermal barrier member  212 . More particularly, it is seen that, for example, four axially extending voids or passageways  246 , 248 , 250 , 252  are formed within the thermal breaker or thermal barrier member  212 , and that the four axially extending voids or passageways  246 , 248 , 250 , 252  are disposed within a substantially symmetrical array around the longitudinal axis of the thermal breaker or thermal barrier member  212  which would be located within the vicinity of the transverse portion  232  of the inverted T-shaped slot  228 . Each one of the four axially extending voids or passageways  246 , 248 , 250 , 252  has a substantially right-triangular cross-sectional configuration, and as a result of being disposed within the aforenoted predetermined substantially symmetrical array, the hypotenuse portions of each substantially right-triangularly configured void or passageway  246 , 248 , 250 , 252  are respectively disposed within the vicinities of, and substantially parallel to, both the upper inlined external surface regions  220 , 222  of the thermal breaker or thermal barrier member  212 , as well as the lower inclined external surface regions  254 , 256  which effectively interconnect the upper domed region  216  of the thermal breaker or thermal barrier member  212  to the lower base portion  214  of the thermal barrier or thermal breaker member  212 . 
   In this manner, it is seen that four inclined rib members  258 , 260 , 262 , 264  are effectively defined between void or passageway  246  and upper inclined surface region  220 , between void or passageway  248  and upper inclined surface region  222 , between void or passageway  250  and lower inclined surface region  254 , and between void or passageway  252  and lower inclined surface region  256 . It is further seen that a vertically oriented structural rib member  266  is effectively defined between the vertically oriented wall members of the voids or passageways  246 , 250  and the vertically oriented wall members of the voids or passageways  248 , 252 , and in a similar manner, a horizontally oriented structural rib member  268  is effectively defined between the horizontally oriented wall members of the voids or passageways  246 , 248  and the horizontally oriented wall members of the voids or passageways  250 ,  252 . 
   In this manner, not only does the strategic disposition of the voids or passageways  246 , 248 , 250 , 252  within the thermal breaker or thermal barrier member  212  serve to define or create the aforenoted structural rib members  258 , 260 , 262 ,  264 , 266 , 268  for rigidifying or reinforcing the thermal breaker or thermal barrier member  212 , but in addition, the provision of the voids or passageways  246 , 248 , 250 , 252  reduces the amount of plastic material required to fabricate the thermal breaker or thermal barrier member  212  such that significantly less plastic material is required to fabricate each thermal breaker or thermal barrier member  212  thereby rendering the manufacturing process more economical or cost-effective. Yet further, the provision of the voids or passageways  246 , 248 ,  250 , 252  within the domed region  216  of the thermal breaker or thermal barrier member  212  provides additional, enhanced thermal insulation properties. It is also noted that a similar void or passageway  270 , having a substantially circular or oval-shaped cross-sectional configuration and providing similar manufacturing and structural attributes, is provided within the lower base portion  214  of the thermal breaker or thermal barrier member  212 . 
   With reference now being additionally made to  FIG. 4 , the detailed structure of the clip  226  will now be described. More particularly, it is seen that the clip  226  is fabricated from a suitable sheet metal blank and is subsequently folded in a predetermined manner so as to have the aforenoted substantially inverted T-shaped cross-sectional configuration comprising a vertically upstanding body portion  272  and the aforenoted horizontally oriented head portion  230 . The vertically upstanding body portion  272  is seen to comprise a single ply member fabricated from the sheet metal blank, however, the horizontally oriented head portion  230  is seen to comprise a two-ply member wherein a first upper side portion  274  of the sheet metal, leading from the vertically upstanding body portion  272 , is effectively folded over beneath itself so as to form an undersurface portion  276 , and subsequently, the undersurface portion  276  is effectively folded over atop itself so as to form an opposite second upper side portion  278 . First and second upper side portions  274 , 278  and undersurface portion  276  therefore, collectively, define the head portion  230  of the clip  226 . It is further seen that the vertically upstanding body portion  272  is provided with a plurality of through-apertures  280 , and that the second upper side portion  278  has a plurality of upper tab members  282  extending integrally therefrom. The tab members  282  are adapted to respectively extend through the through-apertures  280  formed within the vertically upstanding body portion  272  and subsequently be folded downwardly, and still further, the second upper side portion  278  is also provided with a pair of additional end tab members  284  which are adapted to be folded or wrapped around the opposite end edge portions of the vertically upstanding body portion  272 . In this manner, the various folded portions comprising the clip  226  are fixedly and integrally connected together in a locked arrangement such that under wind uplift conditions, such various folded portions of the clip  226  will not become separated from each other so as not to compromise the structural integrity of the clip  226 . It is of course to be noted that in lieu of, for example, the holes  280  and the various folded over tab members  282 , 284 , other means, such as, for example, welding, adhesives, or the like, may be utilized to secure the various portions of the clip  226  together. Still further, the clip  226  could be made from multiple components which would then be fixedly secured together. 
   With reference again being directed back toward  FIG. 3 , it is to be appreciated that the horizontal or transverse portion  232  of slot  228  defined within the thermal breaker or thermal barrier member  212  has a predetermined thickness dimension which is not only sufficient to accommodate the dual-ply thickness dimension characteristic of the head portion  230  of the clip  226 , but in addition, the horizontal or transverse portion  232  of slot  228  has a predetermined thickness dimension which permits the head portion  230  of the clip  226  to be freely movable in the axial direction within the horizontal or transverse portion  232  of the slot  228  so as to accommodate thermal expansions and contractions of the roofing panels. In addition, it is likewise to be appreciated that in view of the fact that the vertically upstanding body portion  272  is characterized by means of a single ply sheet metal thickness, whereas the cross-sectional thickness dimension of the clip  226  at the locations corresponding to the tab members  282 , 284  comprises a three-ply structure, the vertically oriented portions  286 , 288  of the slot  228  formed within the thermal breaker or thermal barrier member  212  have different thickness dimensions which correspond to the aforenoted thickness dimensions defined by the single ply and three-ply regions of the clip  226  so as to not only accommodate such regions of the clip  226  but to also permit the clip  226  to be freely movable in the axial direction with respect to the thermal breaker or thermal barrier member  212  so as to accommodate thermal expansions and contractions of the roofing panels. It is additionally noted that the relatively narrow portion  286  of the slot  228  also serves to minimize or retard the transmission of thermal gradients between the interior of the building and the external environment. 
   With reference now being made to  FIG. 5 , a second embodiment of a new and improved thermal breaker or thermal barrier assembly, constructed in accordance with the principles and teachings of the present invention and showing the cooperative parts thereof, for fixedly connecting mating edge portions of adjacent roofing panels to underlying joist members of a roof decking substructure is disclosed and is generally indicated by the reference character  310 . More particularly, the new and improved thermal breaker or thermal barrier assembly  310  is seen to comprise a thermal breaker or thermal barrier member  312 , a clip  314 , and a tab member  316  mounted upon the clip  314 . It is seen that the clip  314  and tab member  316  are substantially similar to the conventional PRIOR ART clip  12  and tab member  22 , as disclosed within  FIG. 1 , wherein, for example, the tab member  316  is mounted upon the clip  314  so as to be movable with respect thereto in order to permit expansion and contraction conditions for the roofing panels. The clip  314  has a substantially L-shaped cross-sectional configuration comprising a vertically oriented leg member  318  and a horizontally oriented leg member  320 , and it is further seen that the thermal breaker or thermal barrier member  312  is substantially similar to the thermal breaker or thermal barrier member  212 , as disclosed within  FIG. 3 , except for the fact that the thermal breaker or thermal barrier member  312  has a substantially hollow shell structure whereby a substantial reduction in the overall amount of plastic material, required for fabricating the thermal breaker or thermal barrier member  312 , can of course be significantly reduced. 
   More particularly, it is further seen that the thermal breaker or thermal barrier member  312  comprises a horizontally disposed lower base portion  322  and an upper domed portion  324 . The lower base portion  322  is adapted to be seated upon a joist member, not illustrated but similar to the joist member  118  illustrated within  FIG. 2 , of an underlying roofing substructure, and is adapted to be secured to such joist member by means of, for example, a pair of headed bolt fasteners  326 , 326 . The lower base portion  322  is seen to be fabricated so as to comprise upper and lower sections  328  and  330  whereby a transversely oriented slot  332  is formed therebetween so as to accommodate the horizontally oriented leg member  320  of the clip  314 , and it is to be appreciated that the pair of headed bolt fasteners  326 , 326  will pass through the sandwich structure comprising the upper base section  328  of the lower base portion  322 , the horizontally oriented leg member  320  of the clip  314 , and the lower base section  330  of the lower base portion  322 . 
   The upper domed portion  324  is seen to have a substantially diamond-shaped cross-sectional configuration comprising oppositely disposed upper divergent inclined wall members  334 , 336 , an upper substantially planar wall member  338  which is disposed substantially parallel to the horizontally oriented lower base portion  322 , and a pair of oppositely disposed lower convergent inclined wall members  340 , 342  which effectively interconnect the oppositely disposed upper divergent inclined wall members  334 , 336  to the lower base portion  322 . Vertically oriented bores  344 , 344  are formed within the lower base portion  322  and the upper domed portion  324  in a manner similar to that characteristic of the bores  236 , 236  formed within the thermal breaker or thermal barrier member  212  as disclosed within  FIG. 3 , however, it is additionally noted, for example, that suitable plastic bushings, not shown, are disposed around the threaded shank portions of the fasteners  326 , 326  so as to prevent the same from being disposed in contact with the horizontally oriented leg member  320  of the clip  314 . The upper wall member  338  of the thermal breaker or thermal barrier member  312  is also provided with a slot  346  so as to permit the vertically oriented leg member  318  of the clip  314  and the tab member  316  to be disposed therein and to pass therethrough. It is lastly noted that, while not actually illustrated, the external surface portions of the upper divergent inclined wall members  334 , 336 , the upper wall member  338 , and the lower base section  330  of the lower base portion  322  are preferably provided with axially extending rib members similar to the rib members  240 , 242 , 244  as disclosed in connection with the thermal breaker or thermal barrier member  212  of  FIG. 3 . 
   With reference now being made to  FIG. 6 , a third embodiment of a new and improved thermal breaker or thermal barrier assembly, constructed in accordance with the principles and teachings of the present invention and showing the cooperative parts thereof, for fixedly connecting mating edge portions of adjacent roofing panels to underlying joist members of a roof decking substructure is disclosed and is generally indicated by the reference character  410 . More particularly, the new and improved thermal breaker or thermal barrier assembly  410  is seen to comprise a thermal breaker or thermal barrier member  412 , and a clip  414 . It is to be appreciated that the thermal breaker or thermal barrier member  412  is substantially similar to the conventional PRIOR ART thermal breaker or thermal barrier member  112  as disclosed within  FIG. 2 , and similarly for the clip  414  with respect to the clip  226  as disclosed within  FIGS. 3 and 4 , except for the fact that the upper domed portion of the thermal barrier or thermal breaker member  412  is fabricated as a two-part construction comprising first and second mating sections  416 - 1 , 416 - 2  with the first section  416 - 1  being integrally connected to the lower base portion  418  which is adapted to be seated upon, and secured to, a joist member of the underlying roofing substructure. The two-part construction may be fabricated by injection molding, pulltrusion, extrusion, or machining techniques, and accordingly, each one of the thermal breaker or thermal barrier domed sections  416 - 1 , 416 - 2  is respectively provided with a mating slot  420 - 1 , 420 - 2  for accommodating the head portion  422  of the clip  414 . 
   A pair of vertically oriented bores  424 , 424  are likewise respectively molded within the first and second mating domed sections  416 - 1 , 416 - 2  in a counterbored manner for permitting a pair of headed bolt fasteners  426 , 426  to pass therethrough, as well as through cut-out sections  425 , 425  formed within the head portion  422  of the clip  414 , similar to those cut-out sections discussed but not shown in connection with the clip  226  of  FIG. 3 , such that the head portions of the fasteners  426 , 426  will be disposed and seated beneath the head portion  422  of the clip  414  and yet be disposed within the second domed section  416 - 2  so as to not only secure the second domed section to the first domed section  416 - 1 , but in addition, to fixedly secure the thermal breaker or thermal barrier assembly  410  onto the joist member of the underlying roofing substructure. The disposition of the head portions of the fasteners  426 , 426  beneath the head portion  422  of the clip  414  also prevents any interference with any axial movement that the clip  414  may undergo in accordance with roofing panel expansion and contraction conditions. It is also noted that the fabrication of the thermal breaker or thermal barrier member  412  as a two-part injection molding not only reduces the injection molding cycle time for each separate component  416 - 1 , 416 - 2 , but in addition, facilitates the formation of slots  420 - 1 , 420 - 2 , as well as the bores  424 ,  424 . As was the case with the thermal breaker or thermal barrier assembly  310  as disclosed within  FIG. 5 , it is lastly noted that, while not actually illustrated, the external surface portions of the upper divergent inclined wall members  428 , 430 , the upper wall member  432 , and the lower base portion  418  are preferably provided with axially extending rib members similar to the rib members  240 , 242 , 244  as disclosed in connection with the thermal barrier or thermal breaker member  212  of  FIG. 3 . 
   Turning now to  FIG. 7 , a fourth embodiment of a new and improved thermal breaker or thermal barrier assembly, constructed in accordance with the principles and teachings of the present invention and showing the cooperative parts thereof, for fixedly connecting mating edge portions of adjacent roofing panels to underlying joist members of a roof decking substructure is disclosed and is generally indicated by the reference character  510 . More particularly, the new and improved thermal breaker or thermal barrier assembly  510  is seen to comprise a clip  512  and a tab member  514 , movably mounted upon the clip  512 , which are characterized by structures which are substantially similar to those structures that are characteristic of the conventional PRIOR ART clip  12  and tab member  22  as disclosed within  FIG. 1 . The clip  512  is seen to have a substantially L-shaped cross-sectional configuration comprising a vertically oriented leg member  516  and a horizontally oriented leg member  518 , and the tab member  514  is mounted upon the clip  512  by means of a dimpled detent member  520  engageable within a suitable concavity, not shown, such that the tab member  514  is easily displaceable from its normally central disposition upon the clip  512 . The upper region of the vertically oriented leg member  516  of the clip  512  is provided with an axially extending slot  522 , and the tab member  514  is provided with an outwardly projecting, elongated lug portion  524  for guided disposition with the axially extending slot  522 . In addition, the upper end portion of the vertically oriented leg member  516  of the clip  512  is provided with oppositely projecting lugs or ears  526 , 528 , and the tab member  514  is provided with a free end portion  530  which is adapted to be crimped together with the side edge portions of the roofing panels to be secured together. In this manner, the tab member  514 , to which the roofing panels are connected, is capable of being moved with respect to the clip  512  so as to accommodate or permit expansion and contraction conditions for the roofing panels. 
   In accordance with further structural features developed in accordance with the principles and teachings of the present invention, it is additionally seen that, in order to provide the thermal breaker or thermal barrier assembly  510  with thermal isolation properties a plastic sheet  532  is folded over upon itself so as to effectively form a sleeve member which not only covers the free edge portion of the horizontally oriented leg member  518  of the clip  512  but additionally comprises upper and lower sections or plies  534 ,  536  which are adapted to be respectively seated upon the upper and lower surface portions of the horizontally oriented leg member  518  of the clip  512 . A pair of threaded headed bolt fasteners  538 , 538  are adapted to be inserted through particular ones of a plurality of apertures  540  formed within the upper and lower plies  534 , 536  of the sleeve member  532 , as well as within the horizontally oriented leg member  518  of the clip  512 , so as to fixedly secure the thermal breaker or thermal barrier assembly  510  upon the joist of the underlying roofing substructure, and it is noted that plastic bushings, not shown, may be disposed around the shank portions of the fasteners  538 , 538  so as to effectively prevent any metal-to-metal contact between the fasteners  538 , 538  and the horizontally oriented leg member  518  of the clip  512 . As was the case with the thermal breaker or thermal barrier assemblies  310 , 410  as disclosed within  FIGS. 5 and 6 , it is lastly noted that, while not actually illustrated, the external undersurface portion of the lower ply  536  of the sleeve member  532  may be provided with axially extending rib members similar to the rib members  240 , 242 , 244  as disclosed in connection with the thermal barrier or thermal breaker member  212  of  FIG. 3 . 
   Turning now to  FIG. 8 , a fifth embodiment of a new and improved thermal breaker or thermal barrier assembly, constructed in accordance with the principles and teachings of the present invention and showing the cooperative parts thereof, for fixedly connecting mating edge portions of adjacent roofing panels to underlying joist members of a roof decking substructure is disclosed and is generally indicated by the reference character  610 . It is initially noted that the thermal breaker or thermal barrier assembly  610  as disclosed within  FIG. 8  is substantially the same as the thermal breaker or thermal barrier assembly  510  as disclosed in  FIG. 7 , except as will be noted immediately hereinafter, and accordingly, a detailed description of the thermal breaker or thermal barrier assembly  610  will be omitted in the interest of brevity, the description of the same being focused upon the aforenoted differences between the thermal breaker or thermal barrier assembly  610  as disclosed within  FIG. 8  and the thermal breaker or thermal barrier assembly  510  as disclosed within  FIG. 7 . It is also noted that components parts of the thermal breaker or thermal barrier assembly  610 , which correspond to the component parts of the thermal breaker or thermal barrier assembly  510 , will be designated by corresponding reference characters except that they will be within the  600  series. 
   More particularly then, it is initially seen that the clip  612  has a uniquely sculpted configuration wherein the clip  612  still has the substantially L-shaped cross-sectional configuration comprising the vertically oriented leg member  616  and the horizontally oriented leg member  618 , the vertically oriented and horizontally oriented leg members  616 , 618  being connected together by means of oppositely disposed transitional regions  619 , 619 , however, it is additionally seen that the axial extent of the horizontally oriented leg member  618  has effectively been substantially reduced with respect to the axial extent of the vertically oriented leg member  616 . In this manner, the horizontally oriented leg member  618  can nevertheless be fixedly connected to the joist member of the underlying roofing substructure by means of the head bolt fasteners  638 , while reducing the amount of material required to fabricate the horizontally oriented leg member  618 , however the axial extent of the vertically oriented leg member  616  is effectively preserved such that the axial movements of the tab member  614 , connected to the mated side edge portions of the roofing panels, can be preserved to the maximum extent so as to ensure, and not confine, the expansion and contraction movements of the roofing panels. Still further, another unique feature characteristic of this particular embodiment of the thermal breaker or thermal barrier assembly  610  is disclosed in connection with the plastic sheet  632  which is folded over upon itself so as to effectively form a sleeve member which not only covers the free edge portion of the horizontally oriented leg member  618  of the clip  612 , but also comprises the upper and lower sections or plies  634 , 636  which are adapted to be respectively seated upon and cover the upper and lower surface portions of the horizontally oriented leg member  618 , as was the case with the sleeve member  532  of the thermal breaker or thermal barrier assembly  510  as disclosed within  FIG. 7 . 
   More particularly, as can best be seen from  FIG. 8   a , the upper section or ply  634  of the sleeve member  632  is provided with a pair of through-apertures  640 , 640  for accommodating the shank portions of the headed threaded bolt fasteners  638 , while the lower section or ply  636  is integrally provided with a pair of upstanding bushings  642 , 642 . Therefore, when the sleeve member  632  is in fact fully folded upon itself so as to encase the horizontally oriented leg member  618  of the clip  612 , the bushings  642 , 642  will project upwardly and pass through the apertures formed within the horizontally oriented leg member  618  of the clip  612  and also project through the apertures  640 , 640  formed within the upper section or ply  634  of the sleeve member  632 . In this manner, there is no metal-to-metal contact established between the threaded bolt fasteners  638 , 638  and the horizontally oriented leg member  618  of the clip  612 . It is also again noted that, as was the case with the thermal breaker or thermal barrier assemblies  310 ,  410 , 510  as disclosed within  FIGS. 5-7 , the external undersurface portion of the lower ply  636  of the sleeve member  632  may be provided with axially extending rib members similar to the rib members  240 , 242 , 244  as disclosed in connection with the thermal barrier or thermal breaker member  212  of  FIG. 3 . 
   With reference now being made to  FIG. 9 , a sixth embodiment of a new and improved thermal breaker or thermal barrier assembly, constructed in accordance with the principles and teachings of the present invention and showing the cooperative parts thereof, for fixedly connecting mating edge portions of adjacent roofing panels to underlying joist members of a roof decking substructure is disclosed and is generally indicated by the reference character  710 . It is initially noted that the thermal breaker or thermal barrier assembly  710  as disclosed within  FIG. 9  has substantially similar overall geometrical shapes or contours as those of the thermal breaker or thermal barrier assembly  610  as disclosed within  FIG. 8  except that in lieu of the clip  712  being fabricated from steel or a similar metal, as is the case of the clip  612  of the thermal breaker or thermal barrier assembly  610 , the clip  712  is fabricated from a plastic material similar to that used to fabricate the thermal breaker or thermal barrier members  212 , 312 ,and  412  of the thermal breaker or thermal barrier assemblies  210 , 310 , and  410 . In addition, in lieu of clip  712  having a substantially L-shaped cross-sectional configuration as is characteristic of the clip  612 , clip  712  has a substantially T-shaped cross-sectional configuration comprising a vertically oriented plate member  714  and a horizontally oriented platform  716  to which the lower end portion of the vertically oriented plate member  714  is integrally attached. The clip  712  may be fabricated by means of any well-known techniques, such as, for example, injection molding, extrusion, pulltrusion, or the like, and it is further seen that a pair of gussets or angle brackets  718 ,  718  integrally interconnect each side of the lower end portion of the vertically oriented plate member  714  to the horizontally oriented platform  716 . A pair of headed threaded bolt fasteners  720  are inserted through the horizontally oriented platform  716  so as to fixedly connect the clip  712  to the joist member of the underlying roofing substructure. 
   Continuing further, it is also seen that the clip  712  has a uniquely sculpted configuration similar to that of the clip  612 , as disclosed within  FIG. 8 , wherein the upper end portion of the vertically oriented plate member  714  of the clip  712  is integrally connected to the lower end portion of the vertically oriented plate member  714  by means of oppositely disposed transitional regions  722 , 722  whereby, as was the case with the clip  612  of the embodiment disclosed within  FIG. 8 , the axial extent of the horizontally oriented platform  716  is effectively reduced with respect to the axial extent of the vertically oriented plate member  714 . In this manner, the horizontally oriented platform  716  can nevertheless be fixedly connected to the joist member of the underlying roofing substructure by means of the headed bolt fasteners  720 , 720  while reducing the amount of material required to fabricate the horizontally oriented platform member  716 , however the axial extent of the vertically oriented plate member  712  is effectively preserved such that the axial movements of the tab member  724 , connected to the mated side edge portions of the roofing panels, can be preserved so as to effectively permit maximum expansion and contraction movements of the roofing panels. It is lastly seen that the vertically oriented plate member  714  is provided with an axially oriented slot  726 , and that the tab member  724  is provided with a lug member  728  which maintains the tab member  724  movably mounted upon the vertically oriented plate member  714  of the clip  712 . It is also again noted that, as was the case with the thermal breaker or thermal barrier assemblies  310 , 410 , 510  as disclosed within  FIGS. 5-7 , the external undersurface portion of the platform  716 , as well as the upper surface portion  730  of the vertically oriented plate member  714  may be provided with axially extending rib members similar to the rib members  240 , 242 , 244  as disclosed in connection with the thermal barrier or thermal breaker member  212  of  FIG. 3 . 
   Turning now to  FIG. 10 , a seventh embodiment of a new and improved thermal breaker or thermal barrier assembly, constructed in accordance with the principles and teachings of the present invention and showing the cooperative parts thereof, for fixedly connecting mating edge portions of adjacent roofing panels to underlying joist members of a roof decking substructure is disclosed and is generally indicated by the reference character  810 . It is initially noted that the thermal breaker or thermal barrier assembly  810  as disclosed within  FIG. 10  is substantially the same as the thermal breaker or thermal barrier assembly  710  as disclosed within  FIG. 9 , except as will be noted hereinafter, and therefore, in the interest of brevity, a detailed description of the thermal breaker or thermal barrier assembly  810  will be omitted herefrom. It is additionally noted that component parts of the thermal breaker or thermal barrier assembly  810  as disclosed within  FIG. 10 , which correspond to component parts of thermal breaker or thermal barrier assembly  710  as disclosed within  FIG. 9 , will be designated by corresponding reference characters except that they will be within the  800  series. More particularly, it is noted that the only significant difference between the thermal breaker or thermal barrier assembly  810 , as disclosed within  FIG. 10 , and the thermal breaker or thermal barrier assembly  710 , as disclosed within  FIG. 9 , resides in the fact that each one of the oppositely disposed end portions of the upper surface portion  830  of the vertically oriented plate member  814  is provided with a pair of shoulder members  832 , 832  projecting outwardly from the plane of the vertically oriented plate member  814  so as to effectively provide or serve as sculpted or contoured seating means for supporting the side edge portions of the roofing panels to be mated together. It is also again noted that the external undersurface portion of the platform  816 , as well as the upper surface portion  830  of the vertically oriented plate member  814  may be provided with axially extending rib members similar to the rib members  240 , 242 , 244  as disclosed in connection with the thermal barrier or thermal breaker member  212  of  FIG. 3 . 
   With reference now being lastly made to  FIG. 11  in connection with the various embodiments of the thermal breaker or thermal barrier assemblies of the present invention, an eighth embodiment of a new and improved thermal breaker or thermal barrier assembly, constructed in accordance with the principles and teachings of the present invention and showing the cooperative parts thereof, for fixedly connecting mating edge portions of adjacent roofing panels to underlying joist members of a roof decking substructure is disclosed and is generally indicated by the reference character  910 . It is initially noted that the thermal breaker or thermal barrier assembly  910  as disclosed within  FIG. 11  is effectively a hybrid or composite of the structural features and teachings of the thermal breaker or thermal barrier assemblies  610  and  710  as disclosed within  FIGS. 8 and 9 , and therefore, in the interest of brevity, a detailed description of the thermal breaker or thermal barrier assembly  910  will be omitted herefrom. It is additionally noted that component parts of the thermal breaker or thermal barrier assembly  910  as disclosed within  FIG. 11 , which correspond to component parts of the thermal breaker or thermal barrier assemblies  610  and  710  as disclosed within  FIGS. 8 and 9 , will be designated by corresponding reference characters except that they will be within the  900  series. More particularly, it is noted that the thermal breaker or thermal barrier assembly  910  comprises a metal clip  912 , within which there is movably mounted a tab member  914 , and that the metal clip  912  is substantially similar to the clip  612 , as disclosed within the thermal breaker or thermal barrier assembly  610  of  FIG. 8 , except for the fact that the metal clip  912  does not have a substantially L-shaped cross-sectional configuration but, to the contrary, comprises a vertically oriented planar member comprising a vertically upper section  916  and a vertically lower section  918 , the vertically upper and vertically lower sections being connected together by means of oppositely disposed transitional regions  919 , 919 . 
   In addition, in accordance with the unique structural characteristics of the thermal breaker or thermal barrier assembly  910 , it is seen that the vertically lower section  918  of the clip  912  is adapted to be fixedly mounted within a thermal breaker or thermal barrier member  932 . The thermal breaker or thermal barrier member  932  is seen to comprise a horizontally oriented base section or platform  934  and a pair of vertically upstanding plate members  936 , 936  which effectively form a clevis structure so as to accommodate the vertically lower section  918  of the clip  912  therebetween. The base section or platform  934  of the thermal barrier or thermal breaker member  932  is adapted to be fixedly secured to the joist member of the underlying roofing substructure by means of a first pair of headed, threaded bolt fasteners  938 , 938 , and the vertically lower section  918  of the clip  912  is adapted to be fixedly secured between the vertically upstanding plate members  936 ,  936  of the thermal breaker or thermal barrier member  932  by means of a second pair of headed, threaded bolt fasteners  940 , 940 . It is lastly noted that the external undersurface portion of the base section or platform  934  may be provided with axially extending rib members similar to the rib members  244  as disclosed in connection with the thermal barrier or thermal breaker member  212  of  FIG. 3 . 
   With reference now being lastly made to  FIGS. 12-19 , several embodiments of different structures that may effectively be incorporated internally within, or upon the external surface regions of, the various thermal breaker or thermal barrier members or assembly components in order to render the same more thermally efficient, or, in other words, to effectively prevent the occurrence of thermal heat loss, will now be disclosed. For example, in lieu of the axially oriented rib structures  240 , 242 , 244  illustrated within  FIG. 3  in connection with the various external surface regions of the thermal breaker or thermal barrier member  212 , the rib structures  240 , 242 , 244  may effectively be replaced by means of a plurality of wavy or sinusoidal structures or surface projections  1012 , as disclosed within  FIG. 12 , which are integrally incorporated upon the particular external surface component  1010 . In a similar manner, as disclosed within  FIG. 13 , a thermal breaker or thermal barrier assembly  1110  comprises a thermal breaker or thermal barrier member  1112  having a cross-sectional configuration similar to, for example, that of the thermal breaker or thermal barrier member  212 , as disclosed within  FIG. 3 , wherein the thermal breaker or thermal barrier member  1112  comprises a lower base section  1114  and an upper domed section  1116 . The upper domed section  116  comprises oppositely disposed inclined surface portions  1120  and  1122 , and in accordance with this particular embodiment of the present invention, the inclined surface portions  1120 , 1122 , as well as the upper surface portion  1124  of the domed section  1116  and the undersurface portion of the lower base section  1114 , may be provided with a plurality of axially oriented projections  1140 , 1142 , 1144  wherein each one of the axially oriented projections  1140 , 1142 , 1144  has a substantially triangular cross-sectional configuration. Alternatively still further, in lieu of the axially oriented projections  1140 , 1142 , 1144  having the aforenoted cross-sectional configurations, the projections  1140 , 1142 , 1144  could comprise conically configured bumps or projections having the substantially triangular cross-sectional configurations as illustrated. 
   Continuing still further, and with reference being made to  FIG. 14 , it is seen that in accordance with a fourth embodiment of a heat-loss reducing structure, that may be incorporated upon the external surface portions of a thermal breaker or thermal barrier member  1212  of a thermal breaker or thermal barrier assembly  1210  constructed in accordance with the principles and teachings of the present invention, the thermal breaker or thermal barrier member  1212  is illustrated as having an irregular coarse surface structure  1214  which simulates, for example, the external surface of an orange rind. In a similar manner, as illustrated within  FIG. 15 , a thermal breaker or thermal barrier member  1312  of a thermal breaker or thermal barrier assembly  1310 , constructed in accordance with the principles and teachings of the present invention, may have other irregular coarse surface features or structure  1314  which may comprise or simulate, for example, a matte finish, a knurled type finish, or the like. 
   As can be appreciated still further from  FIG. 16 , a sixth embodiment of a heat-loss reducing structure, that may be integrally incorporated upon the external surface portions of a thermal breaker or thermal barrier member  1412  of a thermal breaker or thermal barrier assembly  1410 , as constructed in accordance with the principles and teachings of the present invention, may comprise a plurality of bumps or projections  1414  wherein each one of the plurality of bumps or projections  1414  has a substantially hemispherical cross-sectional configuration and the bumps or projections  1414  are contiguous to, or abut, each other. They may be arranged within a plurality of rows so as to simultaneously form a plurality of columns, and, still further, for example, the rows may also be contiguous to, or abut, each other, such that all of the bumps or projections  1414 , as considered in either one of the mutually orthogonal directions comprising the array of rows and columns, are contiguous to, or abut, each other. 
   With reference now being made to  FIG. 17 , a seventh embodiment of heat-loss reducing structure, that may be integrally incorporated upon the external surface portions of a thermal breaker or thermal barrier member  1512  of a thermal breaker or thermal barrier assembly  1510 , as constructed in accordance with the principles and teachings of the present invention, may comprise a plurality of laterally spaced boss or stud-type standoffs  1514  wherein each one of the plurality of standoffs  1514  has a substantially cylindrical cross-sectional configuration. The number of standoffs  1514  disposed upon any one of the particular external surface portions of the thermal breaker or thermal barrier member  1512  may vary and they may be arranged within, for example, a suitable grid pattern comprising a plurality of rows and columns.  FIG. 18  discloses a still additional eighth embodiment of heat-loss reducing structure, that may be integrally incorporated upon the external surface portions of a thermal breaker or thermal barrier member  1612  of a thermal breaker or thermal barrier assembly  1610 , as constructed in accordance with the principles and teachings of the present invention, wherein the same comprises a plurality dimple members  1614  disposed either within a uniformly arranged, or a non-uniform, randomly arranged array upon the external surface portions of the thermal breaker or thermal barrier member  1612  of the thermal barrier or thermal breaker assembly  1610 . While the dimples  1614  are disclosed as comprising convex structures, the same may alternatively comprise concave structures wherein the plurality of dimples  1614  nevertheless provide the overall external surface portion of the thermal breaker or thermal barrier member  1612  with an irregular surface structure such that surface-to-surface contact is not in fact established between the thermal breaker or thermal barrier member  1612  and the roofing panels or joist member of the underlying roofing substructure. 
   With reference lastly being made to  FIG. 19 , a ninth embodiment of heat-loss reducing structure, that may be internally incorporated within the thermal breaker or thermal barrier member  1712  of a thermal breaker or thermal barrier assembly  1710 , as constructed in accordance with the principles and teachings of the present invention, is disclosed, and it is seen that the same comprises a plurality of air bubbles  1714  disposed either within a uniformly arranged, or a non-uniform, randomly arranged array internally within the thermal breaker or thermal barrier member  1712  of the thermal barrier or thermal breaker assembly  1710 . It is to be noted that the air bubble structures  1714  may be utilized alone or in conjunction with any of the other thermal loss-reducing structures disclosed within FIGS.  3  and  12 - 18 , and when being used alone, even though the external surface portions of the thermal breaker or thermal barrier assemblies would be disposed in surface-to-surface contact with the roofing panels and joist member of the underlying roofing substructure, the thermal flow path would effectively be interrupted by means of the air bubbles  1714  so as to adequately reduce the thermal transmissions. 
   Thus, it may be seen that in accordance with the teachings and principles of the present invention, there has been disclosed thermal breaker or thermal barrier structures, for use in connection with roof decking assemblies, for effectively preventing the respective transmission of heating gradients from the interior or exterior building environments to the exterior or interior building environments by thermal conductivity so as to render the building more energy efficient. 
   Obviously, many variations and modifications of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the present invention may be practiced otherwise than as specifically described herein.