Patent Publication Number: US-2006005492-A1

Title: Building panel

Description:
This application is a continuation in part application of applications Ser. No. NOT YET KNOWN filed 17 Aug. 2004. 
    
    
     FIELD OF THE INVENTION  
      The present invention relates to building panels, and more particularly to building panels including a conduit system for transmission of water vapor.  
     BACKGROUND OF THE INVENTION  
      In the context of exterior building panels, the presence of moisture can lead to undesirable results. Moisture that becomes trapped within and between panels can generate rot in the substrate to which the panel is affixed, it can bleed through the panel finishing coat and discolour it, and it can even cause the panel to detach from the substrate.  
      Prior attempts to address this problem include Canadian Patent 1,220,041 to Larsson, which teaches a panel having drainage channels for use with subterranean wall surfaces. The channels communicate directly with the subterranean wall surface, as the channels are intended to direct water accumulation on the concrete surface away from that concrete surface. U.S. Pat. No. 6,318,041 to Stanley discloses a panel system that also employs drainage channels or conduits.  
      While various attempts have been made to address the problem of moisture in a variety of building panel contexts, a need has been felt for an improved means of addressing the problem in the specific context of Exterior Insulated Finish System (EIFS) technology. The EIFS system, developed in Europe in the 1950s, uses multi-layered exterior wall systems for both commercial and residential buildings, and it typically consists of an interior insulation board secured to the exterior wall surface, a reinforced base coat applied to the insulation board, and a finish coat that is both visually attractive and resistant to environmental impact. The superior energy efficiency and design flexibility of the EIFS system have resulted in growing popularity, but the presence of moisture remains a vexing problem.  
     SUMMARY OF THE INVENTION  
      According to one aspect of the present invention there is provided an insulated building panel for affixing to exterior building surfaces in rows of the panels side by side and top to bottom to form an array of the panels, the building panel comprising:  
      a panel body formed of an insulating foam material, the panel body having:  
      opposed inside and outside surfaces generally parallel to each other;  
      opposed top and bottom horizontal sides arranged for butting engagement with other similar panel bodies;  
      opposed left and right vertical sides arranged for butting engagement with other similar panel bodies;  
      the panel body having therein a plurality of conduits for transmission of water vapour through the array of panel bodies including at least one generally horizontal conduit spaced from the front and back surfaces and a series of transversely spaced generally vertical conduits spaced from the front and back surfaces;  
      the number of vertical conduits and the spacing between the vertical conduits being arranged such that water vapor migrating from the inside surface toward the outside surface is collected in the conduits prior to reaching the outside surface;  
      wherein the at least one horizontal conduit is defined by a groove located at one of the horizontal sides such that the conduit is defined by an open area defined between an adjacent surface of an adjacent panel on one side and a wall of the groove in the panel on the other side with the dimensions of the area so formed being sufficient to allow the passage of water vapor therethrough.  
      Preferably the at least one horizontal conduit is defined by a groove located at one of the horizontal sides and which has an open mouth at the side and converges inwardly toward an apex as it extends into the panel body. This is preferably the top side but may be the bottom side.  
      Preferably the groove has a width at its mouth in the horizontal side of the panel in a direction at right angles to the inner and outer surfaces at least equal to a width in the same direction of the vertical conduits.  
      Preferably the groove has a width at its mouth in the horizontal side of the panel in a direction at right angles to the inner and outer surfaces greater a width in the same direction of the vertical conduits.  
      Preferably that side of the groove which is adjacent the inner surface is substantially coincident with an adjacent side of the vertical conduits and that side which is adjacent the outer surface extends closer toward the outer surface than does the vertical conduit.  
      Preferably one half of the distance between one of the vertical conduits and the next is less than the distance between said one of the vertical conduits and the outer surface such that water vapor tends to migrate to the conduits in preference to the outer surface.  
      Preferably the groove and the vertical conduits are closer to the inner surface than the outer surface.  
      Preferably the groove is V-shaped in cross section.  
      Preferably the vertical conduits are rectangular in cross section.  
      Preferably the vertical conduits are formed by molding such that they are free from a wire cut connection to an external surface of the panel body.  
      Preferably each of the vertical sides includes a groove.  
      Preferably at least one of the vertical and horizontal sides includes a stepped joint.  
      Preferably the stepped joint also includes a groove.  
      According to a second aspect of the invention there is provided an insulated cladding system affixed to an exterior building surface comprising:  
      a plurality of insulated building panels affixed in rows of the panels side by side and top to bottom to form an array of the panels defining an exterior surface;  
      one or more exterior coating layers applied over the exterior surfaces of the panels to form an exterior finish of the building;  
      each building panel comprising a panel body formed of an insulating foam material, the panel body having:  
      opposed inside and outside surfaces generally parallel to each other;  
      opposed top and bottom horizontal sides arranged for butting engagement with other similar panel bodies;  
      opposed left and right vertical sides arranged for butting engagement with other similar panel bodies;  
      the panel body having therein a plurality of conduits for transmission of water vapour through the array of panel bodies including at least one generally horizontal conduit spaced from the front and back surfaces and a series of transversely spaced generally vertical conduits spaced from the front and back surfaces;  
      the number of vertical conduits and the spacing between the vertical conduits being arranged such that water vapor migrating from the inside surface toward the outside surface is collected in the conduits prior to reaching the outside surface;  
      wherein the at least one horizontal conduit is defined by a groove located at one of the horizontal sides such that the conduit is defined by an open area defined between an adjacent surface of an adjacent panel on one side and a wall of the groove in the panel on the other side with the dimensions of the area so formed being sufficient to allow the passage of water vapor therethrough.  
      In exemplary embodiments of the present invention, the building panel is for thermal insulation and for collection and drainage of moisture from water vapour, and the building panel is made of expanded polystyrene or polyisocyanurate. The generally horizontal groove is preferably V-shaped in cross section and configured to facilitate lateral movement of moisture from water vapour to the at least one generally vertical channel for downward flow of the moisture through the at least one generally vertical channel, and the at least one generally vertical channel is preferably rectangular in cross section. The building panel is preferably of unitary, shape-moulded construction.  
      By providing a building panel that can both insulate and efficiently direct moisture from water vapour away from the panels and underlying substrate, while serving the need for an even surface for application of the base and finish coats, the present invention is intended to address a pressing need in the industry.  
      A detailed description of an exemplary embodiment of the present invention is given in the following. It is to be understood, however, that the invention is not to be construed as limited to this embodiment. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      In the accompanying drawings, which illustrate an exemplary embodiment of the present invention:  
       FIG. 1  is a side cross-section along line I-I in  FIG. 2  of an in situ assembly of building panels according to the present invention.  
       FIG. 2  is a front elevation of the assembly of  FIG. 1 .  
       FIG. 3  is a plan view of a building panel according to the present invention.  
       FIG. 4  is a top plan view on an enlarged scale of one part of one of the panels of the previous figures.  
       FIG. 5  is a cross sectional view transversely through two of the panels stacked one on top of the next.  
       FIG. 6  is a cross sectional view similar to that of  FIG. 4  showing a modified arrangement with a ship-lap connection between the panels. 
    
    
     DETAILED DESCRIPTION OF AN EXEMPLARY EMBODIMENT  
      Referring now in detail to the accompanying drawings, and particularly to  FIGS. 1 and 2 , there is illustrated an assembly of building panels according to the present invention, each panel being referred to generally by the numeral  10 . The building panel  10  comprises opposed front and back sides  14 ,  16  generally parallel to each other and opposed top and bottom edges  18 ,  20  generally parallel to each other. Conduits for transportation of water vapor are provided in the panel including a generally horizontal V-shaped groove  22  in the top edge  18  spaced from the front and back sides  14 ,  16 , and generally vertical channels  24  extending downwardly from the groove  22  though the building panel  10  to the bottom edge  20  at a point on the bottom edge  20  spaced from the front and back sides  14 ,  16 . Thus the V-shaped groove is located at the surface and has an open mouth at the surface and converges inwardly and downwardly into the panel body to an apex. While  FIG. 2  shows the channels  24  only in the centrally positioned building panel  10 , the channels  24  are also in each of the adjacent building panels  10 . The building panel  10  is of a unitary, shape-moulded construction, an advantage over traditional wire-cut construction since the vertical channels are free from the necessary wire cut entry slot from an adjacent surface of the panel.  
      As can be seen in  FIG. 1 , interior surface of the building panel  10  is includes an air barrier membrane  26  which is applied to an exterior surface  12  of a building  13  as an air/vapour barrier by an adhesive  28 . In the illustrated embodiment the adhesive  28  is applied as a layer prior to positioning of the building panel  10 .  
      Thus the exterior building surface  12  is arranged to be suitable for application of the building panels  10 . Suitable substrates include but are not limited to exterior grade drywall, cement board, plywood sheathing, Dens-Glass sheathing, precast concrete, concrete block, or poured-in-place concrete. The air/vapour barrier membrane  26  is applied to the exterior building surface  12 . An adhesive  28  is then applied on top of the membrane  26 .  
      The building panels  10  are then applied over this adhesive layer  28  and secured in place thereby. For a building of four stories or greater it is advisable to use mechanical fasteners as well to secure the panels to the exterior building surface  12 .  
      The building panels  10  are preferably arranged in the offset pattern shown in  FIG. 2 , a pattern well known in the art. The joints between the building panels  10  should be sealed with a suitable material (not shown) known to those skilled in the art to further enhance the insulating properties of the building panels  10 .  
      Various methods of providing base and finishing coats (not shown) are then possible, according to the general knowledge of those skilled in the art of EIFS use.  
      With the building panels  10  now in place on the exterior building surface  12  and finished in a suitable manner, the groove  22  is now configured to facilitate lateral movement of water vapour to the channels  24  for downward flow of the water vapor through the channels  24 . Water vapor can flow horizontally through a groove  22  and into adjacent grooves  22  as necessary, while the channels  24  then provide vertical conduits for the water vapor flowing through the grooves  22 .  
      As is well known in the EIFS system, the exterior cladding formed by the rows and columns of panels of insulating foam are covered on the exterior surface by a first layer  30  which is a flexible mortar layer commonly having embedded therein a reinforcing fiber layer together with an exterior coating  31  of a flexible coloured material. These coatings are well known to one skilled in the art and commonly used. Different types of coating can be used.  
      Each of the blocks or panels forming the system therefore comprises the block as defined above which has an interior surface of the foamed insulation material indicated at  32  and an exterior surface  33 . These surfaces are parallel and defined on the exterior of the insulation material which forms the block and is located therebetween. The block further includes horizontal sides  34  and  35  at the top and bottom respectively and vertical sides  35  and  36 . These sides are at right angles to the front and rear surfaces so as to form a rectangular block or panel of the required thickness with each of the panels being of the same height and the same width. The panels are then arranged in rows with the top and bottom surfaces abutting and the sides surfaces also abutting.  
      The exterior coating surfaces  30  and  31  are applied directly onto the outside surface and there are no external sheeting elements.  
      The conduit system defined in the present invention is arranged to communicate moisture in the form of water vapour through the system to an exterior location. The system is not intended to nor required to communicate any form of flowing water since the amount of moisture which can penetrate is very low. The required escape of moisture is therefore also very low but, if prevented from escape, can collect over time which may be many weeks or many months leading to that moisture penetrating through the permeable foam to the exterior surfaces  30  and  31  causing damage thereto.  
      Differential pressures across the foam panels can cause water vapour to transfer or permeate through the structure. The water vapour tends to migrate to paths of least resistance so that, provided the conduit system provides sufficient cross sectional area of the conduits, the water vapour will tend to migrate to these conduits and pass therethrough in gaseous form in the air contained within the conduits to any exterior vent.  
      As best shown in  FIGS. 4 and 5 , the vertical conduits  16  are arranged in a series spaced along the length of the panel. Thus as shown in  FIG. 5 , each of the conduits  16  is rectangular in cross section and has a width W with a spacing between each conduit and the next of S. The conduits are arranged so that the distance D 1  from the inner surface  32  is less than the distance D 2  from the outer surface  33 . Also the spacing S between each conduit and the next is arranged so that moisture tending to migrate from the inside surface  32  toward the outside surface has a shorter distance to travel to the conduit  16  than to the exterior surface  33  along the distance D 2 . Thus moisture at a point P in the panel tends to migrate along the distance S/2 to the conduit  16  than over the distance D 2  to the exterior surface. Thus any moisture contained between the vapour barrier  26  and the panel will tend to migrate to the conduits and travel along the conduits as water vapour to an exterior vent.  
      In order to provide horizontal transfer of the water vapour, there are provided the grooves  22 . These are preferably provided in the top surface  34  of the panel  10  but could additionally be provided in the bottom surface  35  of the panel  10 A or could be provided only in the bottom surface  35  of the panel  10 A. However these grooves are provided at the surface so that the groove has an open mouth  22 A at which is located a portion  35 A of the bottom surface  35  closing the open mouth  22 A. Further the conduit is defined by portions  22 B and  22 C of the groove converging to an apex  22 D. Thus the groove converges inwardly towards the apex as the groove extends into the body of the panel.  
      This arrangement allows the grooves to be formed as common action in molding the vertical conduits  16 . Thus a mold which is generally rectangular in the form of the shape of the panel also includes insert elements which define the groove  22  and the channels or conduits  16 . Thus a bar which is triangular in shape defines the groove  22  and the bar houses a plurality of projecting rods of rectangular cross section which define the channel  16 . After the injection of the foam and the molding of the foam material into the required shape, the rods forming the channel  16  and the bar forming the groove  22  are pulled outwardly from the top face of the block to complete the molding of the hollows within the block defining the groove  22  and the channel  16 . Preferably similar insert rods are provided at the opposite end forming the bottom  35  of the block  10  so that the rods forming the channel  16  extend only over one half of the length of the channels allowing them to be pulled in opposite directions from a junction point half way along the channels.  
      This shape-forming process in which the panels are molded including the molding of the channels and grooves provides a high efficiency forming system in which the whole structure is formed in one molding action without the necessity for cutting elements from the foam. Wire cutting systems require the necessity for an inlet and exit slot which are not necessary in the structure of the present invention.  
      The channels  16  are arranged in a common plane and directly aligned. The channels  16  have an inner surface  16 A and an outer surface  16 B. The groove  22  is arranged so that one end of the side portion  22 C terminates at a position coincident with the side  16 A of the channel  16 . The groove  22  has a width greater than the width of the channel between the surfaces  16 A and  16 B. Thus the apex  22 D is located at a position generally aligned with the surface  16 B. Thus the portion  22 B extends from the apex further outwardly of the surface  16 B toward the outer surface  33 . In this way, the cross sectional area of the groove  22  approximates to the cross sectional area of the rectangular channel  16  to provide approximately a similar cross sectional area for transmission of water vapour therethrough. It is clear that the amount of water vapour transmitted is generally proportional to the cross sectional area so that sufficient cross sectional area is provided both in the channel  16  and in the groove  22 . Thus the groove  22  has a width at least equal to the width of the channel  16  and preferably greater in view of the triangular shape. The location for the groove at the surface allows water vapor to migrate from one vertical channel in one panel to one in the next without the necessity to align the channels in the panel assembling process.  
      The groove and the channels are arranged closer to the inner surface  32  than the outer surface  33  in order to ensure that moisture preferentially enters the channels rather than reaches the exterior surface  33  where damage can be caused.  
      As shown in  FIG. 6 , the top and bottom surfaces indicated at  34 A and  35 A include a ship-lap section generally indicated at  40  wherein there is a surface  41  which extends parallel to the inside and outside surfaces  32  and  33 . Thus the surface  34 A is divided into a first portion  34 B and a second portion  34 C and similarly the surface  35 A is divided into a first portion  35 B and a second portion  35 C. Between these two portions is the surfaces indicated at  41 . The groove indicated at  22 X is formed from the portion  34 C of the block  10 . A further groove  22 Y is formed in the surface  41  between the portions  34 C and  34 B. The groove  22 Y thus further acts as trap for moisture tending to migrate along the surfaces  34 A and  35 A. This trap thus acts to collect water vapour and to transmit that water vapour to discharge. It will be noted that the groove  22 X is the same width as the channel  16 .  
      An additional groove can be provided in the vertical sides of the block again to act as a trap for any moisture migrating between the blocks.  
      While a particular embodiment of the present invention has been described in the foregoing, it is to be understood that other embodiments are possible within the scope of the invention and are intended to be included herein. Thus, while the embodiment illustrated in  FIGS. 2 and 3  includes fifteen equally-spaced channels  24  per building panel  10 , but it may be preferable to have nineteen or some other number of channels  24  depending on the application.  
      While particular substrates have been identified in the foregoing, it is to be understood that the application of the panel to any substrate is to be considered within the scope of the invention. Currently it is considered that the invention may not be especially useful with certain types of substrate, including oriented strand board and chipboards. It will therefore be clear to those skilled in the art that modifications of and adjustments to this invention, not shown, are possible without departing from the spirit of the invention as demonstrated through the exemplary embodiment. The invention is therefore to be considered limited solely by the scope of the appended claims.