Patent Publication Number: US-2006005494-A1

Title: Shingled siding unit

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
      This application claims priority to U.S. Provisional Patent Application No. 60/561,941, filed Apr. 13, 2004, entitled SHINGLED SIDING UNIT, which application is incorporated herein in its entirety by this reference. 
    
    
     BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      This invention relates, in general, to shingled siding units, and more particularly to panel assemblies and corner assemblies that are useful to form the exterior surface of a building structure, and to methods for their use.  
      2. Description of Related Art  
      Shingles are frequently used for walls or roofs of structures. Wood shingles are attractive and they require little maintenance. Producing a shingled wall or roof by nailing individual shingles to sheathing is expensive because it consumes a great deal of time and because many shingles are often broken during shipping and installation.  
      To reduce the cost of shingled structures and still preserve the advantages of shingles, prefabricated panels having shingles mounted on a backing or base sheet have been made. Various problems are associated with known prefabricated shingled panels. Generally, the panels must be mounted in a tight-fitting configuration side-to-side and top-to-bottom, not only to simulate the random shingled appearance of a hand shingled wall, but also to prevent leakage between adjacent panels.  
      Furthermore, one side of prior shingled panels is generally trimmed along a straight line in order to cooperate with known shingled corners. Disadvantageously, the resulting joint between the panels and the corners is substantially linear and fails to interweave the shingles of the panel with the shingles of the corner. Not only does the linear joint prevent a random shingled appearance, the linear joint is limited in terms of water-resistance and relies instead on the caulking or other sealing means, between the panel and the corner.  
      What is needed is improved shingled siding units which overcome the above and other disadvantages of known shingled panels.  
     BRIEF SUMMARY OF THE INVENTION  
      In summary, one aspect of the present invention is directed to a shingled siding unit adapted for mounting to a wall or roof of a building structure including a substrate having outer and inner surfaces, at least one course of side-by-side shingles extending across and mounted to the outer surface of the substrate. The shingles in a lowermost course on the substrate may have lower ends that extend below a lower edge of the substrate configured to overlap an upper edge of a similarly formed siding unit mounted in a vertically abutting relation to the siding unit. The unit further includes spacing strips extending across and secured to the inner surface of the substrate defining at least one ventilation channel between the spacing strips.  
      Preferably, the spacing strips extend substantially vertically along the inner surface of the substrate. The spacing strips may be formed of plywood strips. The siding unit may be substantially planar and may be a plywood panel. Alternatively, the shingled siding unit may be a corner assembly and may include two interconnected panels. The spacing strips may be substantially parallel to a joint formed by the intersection of the interconnected panels. One of the spacing strips may extend along the joint. One of the spacing strips may extend along, or along and beyond, a free edge of one of the interconnected panels.  
      In one embodiment, the lowermost course may include a lowermost protruding end shingle on a first side of the substrate and a lowermost recessed end shingle on a second side of the substrate, the lowermost protruding and recessed end shingles being respectively mounted to protrude laterally beyond and to be laterally recessed with respect to the first and second side edges of the substrate by a substantially equal first distance. The shingled siding unit may include at least two courses mounted to the outer surface of the substrate, with an upper course vertically overlapped over a portion of the lowermost course. The upper course may include an upper recessed end shingle on the first side of the substrate and an upper protruding end shingle on the second side of the substrate, the upper recessed and protruding end shingles being respectively mounted to be laterally recessed and to protrude laterally beyond with respect to the first and second side edges of the substrate by a substantially equal second distance. The shingled siding unit may include at least three courses mounted to the outer surface of the substrate, with an uppermost course vertically overlapped over a portion of the upper course. The uppermost course may include a uppermost protruding end shingle on the first side of the substrate and a uppermost recessed end shingle on the second side of the substrate, the uppermost protruding and recessed end shingles being respectively mounted to protrude laterally beyond and to be laterally recessed with respect to the first and second side edges of the substrate by a substantially equal third distance.  
      The shingled siding unit may include a water impervious membrane extending across the substrate and mounted between the shingles and at least one of the substrate and a lower course of the shingles. The membrane may be provided by a plurality of strips of roofing felt with a first of the strips mounted on the substrate under the lowermost course. A second of the strips may overlap the upper ends of the lowermost course and overlapping the first of the strips. The lower edge of the substrate may include a beveled surface facing in an outward direction with respect to the panel, and the base may be formed with a lower edge having a transverse shoulder and a beveled surface facing in an inward direction with respect to the panel.  
      In one embodiment, the upper and lower edges of the substrate may be formed and dimensioned such that when respective upper and lower edges of similarly formed siding units are in the vertically abutting relation, a gravity-driven film of liquid flows freely across the edges. One of the edges of the substrate in the vertically abutting relation may include a beveled surface. Both of the edges of the substrate in the vertically abutting relation may include a beveled surface. The beveled surfaces may have unequal bevel angles. Each of the edges of the substrate in the vertically abutting relation may include a beveled surface, and the abutting relation may be such that portions of the beveled surfaces are separated by a vertical gap. The upper and lower edges of the substrate may be formed and dimensioned such that when the siding unit and the similarly formed siding unit are mounted in the vertically abutting relation with the similarly formed siding unit elevationally below the siding unit, an uppermost portion of the upper edge of the similarly formed siding unit is elevationally below the lower edge of the siding unit.  
      Another aspect of the present invention is directed to a shingled corner assembly adapted for mounting to a wall or roof of a building structure, the shingled siding unit includes a substrate having inner and outer surfaces formed by two interconnected panels and at least one course of side-by-side shingles extending across and mounted to the outer surface of the substrate. The shingles in a lowermost course on the substrate may have lower ends that extend below a lower edge of the substrate being configured to overlap an upper edge of a similarly formed lower corner assembly mounted in a vertically abutting relation to the corner assembly. The corner assembly further includes spacing strips extending across and secured to the inner surface of the substrate defining at least one ventilation channel between the spacing strips.  
      Preferably, the spacing strips extend substantially vertically along the inner surface of the substrate. Preferably, the spacing strips may be substantially parallel to a joint formed by the intersection of the interconnected panels. Preferably, the spacing strips may be formed of plywood strips. One of the spacing strips may extend along the joint. Another of the spacing strips may along, or along and beyond, a free edge of one of the interconnected panels. The lowermost course may include a lowermost protruding end shingle on a first side of the substrate and a lowermost recessed end shingle on a second side of the substrate, the lowermost protruding and recessed end shingles being respectively mounted to protrude laterally beyond and to be laterally recessed with respect to the first and second side edges of the substrate by a substantially equal first distance.  
      An object of the present invention is to provide a prefabricated shingled siding unit configured to reduce the accumulation of moisture and water vapor between the shingled siding unit and the building structure to which it is installed.  
      A further object of the present invention is to provide cooperating panel and corner assemblies that facilitate the construction of wall and roofs having a random shingled appearance and enhanced weather resistance.  
      The shingled siding units of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated in and form a part of this specification, and the following Detailed Description of the Invention, which together serve to explain the principles of the present invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  and  1 A are a front perspective views of shingled siding units in the form of panel assemblies constructed in accordance with the present invention.  
       FIGS. 2 and 2 A are rear perspective views of the panel assemblies of  FIG. 1  and  FIG. 1A , respectively.  
       FIGS. 3 and 3 A are front perspective views of shingled siding units in the form of corner assemblies constructed in accordance with the present invention.  
       FIGS. 4 and 4 A are rear perspective views of the corner assembly of  FIG. 3   FIG. 3 , respectively.  
       FIG. 5  is a side perspective view of the corner assembly of  FIG. 3 .  
       FIG. 6  is an end elevational view of the corner assembly of  FIG. 3  showing the relationship between two vertically adjacent corner assemblies.  
       FIG. 7  is an enlarged end elevational view of the corner assembly of  FIG. 3  corresponding to area  7 - 7  of  FIG. 6 .  
       FIG. 8  is a cross-sectional view of the lower corner assembly of  FIG. 6  taken along line  8 - 8  of  FIG. 6 .  
       FIG. 9  is a front perspective view of a modified shingled corner unit similar to that shown in  FIG. 3 .  
       FIG. 10A - FIG. 10E  are side views illustrating the relationship between two vertically adjacent siding units according to an aspect of the invention.  
       FIG. 11  is a side view of a ringed shank nail. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      Reference will now be made in detail to preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. While the invention will be described in conjunction with the preferred embodiments, it will be understood that they are not intended to limit the invention to those embodiments. On the contrary, the invention is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims.  
      Turning now to the drawings, wherein like components are designated by like reference numerals throughout the various figures, attention is directed to  FIG. 1  and  FIG. 2 , which figures illustrate a shingled siding unit in the form of a panel assembly, generally designated  30 , constructed in accordance with the present invention. In some aspects, the shingled panel assembly is similar to that disclosed by U.S. Pat. No. 4,731,970 to Marshall et al., the entire content of which is incorporated herein by this reference. Further attention is directed to  FIG. 3  through  FIG. 5 , which figures illustrate a shingled siding unit in the form of a corner assembly, generally designated  31 , also constructed in accordance with the present invention. While for illustration purposes these figures show preferred embodiments having three courses of shingles, other preferred embodiments have a single course of shingles, as are shown in  FIGS. 1A, 2A ,  3 A,  4 A and  5 A. Further embodiments have two, or four, or more than four courses of shingles.  
      The shingled siding units of the present invention may be configured to reduce accumulation of moisture and water vapor behind the inner surface thereof when the unit is installed on a building structure. First, the shingled siding units are provided with spacing means that define ventilation channels between the unit and the building structure, which ventilation channels facilitate the drainage or evaporation of moisture between an installed unit and the exterior surface of the building structure. In particular, the ventilation channels define drainage paths that allow any liquid condensation, which may form between the unit and the building structure, to run down the ventilation channel under the force of gravity. Ventilation channels also provide a circulation path through which circulating air may further remove moisture by evaporation.  
      Also, as described in detail below, the portion of the ventilation channel formed by the shingled siding units optionally has reduced or eliminated ledge-like protuberances formed by jutting edges of the vertically adjacent siding units. With such obstructions within the ventilation channel reduced or eliminated, liquid condensate formed on the siding unit&#39;s substrate can freely run down to earth along the substrate surface. Specifically, as an option, embodiments may have upper and lower edges of the substrate which are formed and dimensioned such that when respective upper and lower edges of similarly formed siding units are in a vertically abutting relation, a gravity-driven film of liquid flows freely and unobstructed across the edges. Otherwise, obstructed by ledge-like protuberances due to less advantageous abutment, liquid can stagnate or pool on the protuberances and subsequently and/or accumulate within the crevices formed by the abutting edges of vertically oriented panels.  
      Due to these configurations, the shingled siding units of the present invention are particularly suited for covering the exterior sheathing of building structures that have been covered with a housewrap product because the ventilation channels preserve a drainage plane function of housewrap in the context of use with close fitting siding. In turn, this may reduce moisture damage to the siding because moisture from the interior of the building can condense and drain along the housewrap to earth, and not soak through the siding to ambient air.  
      Housewrap products, such as those sold under the trademark TYVEC by E.I. DuPont de Nemours and Company of Wilmington, Del., is permeable to water vapor and impermeable to liquid water. Accordingly, housewrap serves as a triple function weather barrier in that it reduces the flow of air in to and out from a building, stops liquid water from entering a building, and acts as a vertical drainage plane for liquid films or droplets. The ventilation channels of the present invention preserve the functionality of housewrap from being reduced because the channels allow any moisture and/or condensation, which may form between the housewrapped sheathing of the building structure and the inner surface of the shingled siding unit, to readily escape despite the tight-fitting configuration of the shingled siding units when installed on a building structure. In particular, liquid condensate may freely flow along the housewrap vertical drainage plane despite siding. Without such ventilation channels, in contrast, a tight-fitting configuration of shingles or shingled siding units may inhibit the drainage plane function of housewrap by obstructing the plane. Accordingly, the shingled siding units of the present invention are particularly suited to reduce the occurrence of water damage on the building structure or the unit.  
      As noted above, the shingled siding unit of the present invention is particularly suited for installing on housewrapped exterior sheathing of building structures including, but not limited to garages, houses, hotels and the like. One will also appreciate that the shingled siding unit of the present invention is equally suited for use in covering interior walls in such a manner to simulate the random shingled appearance of a hand shingled wall.  
      Turning first to the shingled siding unit shown in  FIG. 1  and  FIG. 2 , panel assembly  30  includes a sheet-like base or substrate  32  that is preferably made of plywood, particleboard or other material that is weather resistant. For the purpose of convenience the positions of the various members will be described herein with the panel assembly assumed to be in a vertical or at least inclined orientation. Panel assembly  30  may be used for wall or roofing, although it is particularly well suited for use as exterior siding, however, one will appreciate that the panel assembly may also be used as exterior sheathing provided that the base is sufficiently sized and dimensioned for such purpose.  
      In the illustrated embodiment, panel assembly  30  has three courses of shingles attached to base  32 . Again, however, one will appreciate that the same teaching provides for one, two, three, four, or more than four courses. It is preferred that the panel assembly be constructed with wooden, and most preferably with cedar shingles, but it will be understood that many of the advantages of the panel assembly of the present invention will accrue if the shingles are formed with synthetic or non-wooden materials.  
      In the illustrated three-course embodiment, the bottom or lowermost course  33  of shingles consists of shingles  34  that may have random or uniform widths. Lowermost course  33  of shingles is mounted on base  32  so that the butt or thicker, lower ends  35  protrude beyond a bottom edge  36  of base  32  so as to permit overlapping with the top course of shingles in a next lower, similarly-formed panel assembly (not shown). For this purpose lowermost shingles  34  may extend beyond base  32  by about one and one-half inches. The upper portions or upper thin ends of shingles  34  are secured to the base  32  with suitable fasteners, such as galvanized eighteen gauge staples  37 . Preferably, upper staples  37  are driven through the upper narrow portion of the shingles from the front or shingled side of panel assembly  30 .  
      To insure waterproof construction, a first, lower water-resistant membrane strip  38  is placed on base  32  beneath the bottom course of shingles  33 . Strip  38  advantageously may be provided by conventional fiberglass-based roofing felt. Membrane strip  38  is positioned so that its upper edge lies below the upper ends of shingles  34 , and the lower edge of membrane strip  38  extends beyond bottom edge  36  of the base. Membrane strip  38 , however, extends beyond bottom edge  36  of the base a lesser distance than which the lower ends of shingles  34  extend beyond the base.  
      Membrane  38  is positioned on base  32  before the lowermost course of shingles  34  are attached to it, and the positions of upper staples  37  preferably are such that they hold both shingles  34  and membrane  38  in place, that is, the upper staples pass through the shingles and roofing felt and into base  32 . Membrane strip  38  is provided with one or more transversely extending openings  39  which expose base  32  through them. The openings  39  are filled with an adhesive, for example, a first adhesive bead  40 , so that shingles  34  are glued directly to the base  32  by a bead of adhesive material that extends over substantially the entire width dimension of each shingle.  
      In order to further secure shingles  34  to the base, the shingles preferably are secured by second, lower fasteners such as lower staples  41  driven through the backside of panel assembly  30  and into the butt or lower thick ends of the shingles. Back-stapling of the panel assemblies is preferably accomplished after all the courses have been secured by upper staples  37  and adhesive beads, and such back-stapling greatly augments upper staples  37 , which only pass through a relatively narrow section of the shingles. In this manner shingles  34  are held to base  32  both by their upper portion, through upper staples  37 , and their lower portion, through the wood-to-wood adhesive as well as by lower staples  41 , thereby being fastened to base  32  with great stability.  
      The shingled siding units of the present invention can be formed with a single course of shingles; or the units may be formed with two, three, four or more courses. In some preferred embodiments, the panel assembly has at least three courses of shingles. Other preferred embodiments constructed under the same teachings, however, have a single course. Practical circumstances that may favor single course embodiments are described below.  
      In embodiments having at least three courses, a middle course  42  of shingles is composed of middle shingles  43  which overlap shingles  34  of the lowermost course of shingles. Beneath the middle course of shingles  43  and overlapping upper ends of lower shingles  34  is a second, middle water-resistant membrane strip  44  which extends from a distance just short of the upper end of middle shingles  43  to a distance short of the bottom end of shingles  43 . Middle membrane  44  overlaps the upper portion of each lower shingle in first course  33  as well as the respective lower staples  37 , as well as the upper edge of lower membrane strip  44 . Thusly, water running off of the middle course onto the lower course of shingles will drain from the panel assembly without coming into contact directly with base  32  or the lower staples securing shingles  34  to the base.  
      Middle shingles  43  and middle membrane strip  44  are also fastened to base  32  with upper and lower staples in the same manner as discussed above. It is noted that the staples which secure the butt ends of middle shingles  43  also pass through the upper ends of lower shingles  34  to assist further in securing these shingles. A second bead of adhesive may also be used to further secure the middle course of shingles  43  to the upper surface of lower course shingles  34 .  
      In the illustrated embodiment, panel assembly  30  also includes a third, uppermost or top course  45  of shingles  46 . The upper ends of each shingle  46  are positioned closely adjacent to an upper edge  47  of the base. Shingles  46 , as well as a third or top water-impervious membrane  48 , are also secured to the base with upper and lower staples in the same manner discussed above. The upper edge of top membrane strip  48  underlies the upper portion of each shingle  46 . The lower edge of membrane strip  48  extends to a position covering the upper staples holding middle shingles  43  to the base but short of the lower ends of the upper course of shingles  46 . A third bead of adhesive may also be used to provide a wood-to-wood bond between upper shingles  46  and middle shingles  43 .  
      While one embodiment described above has three courses of shingles, other embodiments have a single course, as is shown in  FIG. 1A . Under particular circumstances of use, a single course embodiment may be preferable to multiple course embodiments.  
      For example, while a three-course unit offers users a potential time saving over a single course when applied by multiple workers, a single course unit is easier to handle and maneuver on a construction jobsite and is substantially easier to apply by a single worker. In windy conditions, a multiple course unit may be difficult to control and may even be dangerous. As well, single course embodiments may be preferable in view of construction economics and jobsite timing in that there is no need to schedule finish work on exposed nails or other fasteners that attach single course units to a building. There is no finish work to be done because attachment nails or other fasteners of one single course unit are simply covered upon subsequent attachment of another unit above. In contrast, using three course units will lead to fastening nails being exposed because secure attachment requires nails in the upper, lower, and middle portions of the unit. Such nail or fastener exposure is an unattractive esthetic needing finish work, which may require sub-contracting and scheduling another tradesman. Thus, depending on many factors such as weather, number of workers and their skill and experience, single course units may be most preferable.  
      Turning now to the corner assembly shown in  FIG. 3  through  FIG. 5 , corner assembly  31  is constructed in a manner similar to panel assembly  30  discussed above, and the same reference numerals are used to designate corresponding parts. As is the case with the siding units described above, while a three-course embodiment of a corner assembly is shown for illustration purposes, other embodiments of a corner assembly constructed according to the same principles have a single course of shingles as shown in  FIG. 3A .  
      In particular, corner assembly  31  includes a substrate or base  32  having a plurality of shingles arranged in courses. Unlike prior shingled corners, the shingles of corner assembly  31  are configured to cooperate and interweave with the shingles of adjacently installed panel assemblies and/or with other corner assemblies, as will become apparent below. In the illustrated three course embodiment, corner assembly  31  includes a lowermost course  33 , a middle course,  42  and an upper course  45 .  
      The base of the corner assembly is formed of a pair of interconnected panels  49  and  50  that are arranged in a predetermined angle with respect to one another. The panels may be made of plywood, particleboard, or other suitable material. In the illustrated embodiment panel  49  and  50  form a right angle, however, one will appreciate that the panels may also be arranged in an oblique angle, including both acute or obtuse angles. Preferably, panels  49  and  50  are fastened together in a well-known manner, for example, with fastening means including, but not limited to, nails, staples, adhesive or the like.  
      As the width of corner assembly  31  is significantly shorter than panel assembly  30 , fewer shingles are required to cover the outer surface of the corner assembly. In the illustrated embodiment, each course only includes two shingles; one attached to each of panels  49  and  50 . One will appreciate that the widths of the panels and/or of the shingles may vary and that each course may be formed of one, two, three or more shingles. Preferably, the shingles of corner assembly  31  are arranged in a “Boston weave”, that is, each course of shingles is off-set in a different direction, as most clearly shown in  FIG. 3 . The Boston-weave configuration provides a finished shingled-corner that enhances weather-resistance in a well-known manner. Preferably, suitable fasteners such as corner staples  51  and/or other suitable fastening means are employed to join abutting corner shingles together.  
      In embodiments having multiple shingle courses, one will appreciate from  FIG. 1  and  FIG. 3  that as siding units are mounted on a building moving laterally out from a first corner unit towards a second corner, most circumstances will require that the siding units be cut vertically near to the second corner. This is the case because, in most circumstances, a building dimension is not an integer multiple of the widths of siding units plus two corner units. Once such a straight vertical cut is made across the multiple courses of a siding unit to accommodate for the final non-integer length, the unit may be mated with a corner assembly having non-staggered courses, like the corner assembly in  FIG. 9  and unlike the staggered courses of the corner assembly in  FIG. 3 . With multiple course embodiments, therefore, some corners have shingle edges in a straight line over the multiple courses.  
      Advantageously, siding unit embodiments having a single shingle course offer a staggered appearance at every corner because, in contrast to the multi-course embodiments, each course of shingles is individually cut near the second corner mentioned above. The lateral extent of each course being individually selectable, not grouped, a staggered appearance can be maintained along all corners with either single course corner units or multi-course corner units having staggered shingles. In the case that the builder or developer prefer a more random-like staggering of shingle courses, single course corner units in combination with single course siding units are preferred over single course siding units in combination with multi-course corner units.  
      Turning now to the interwoven shingle configuration shown in  FIG. 1  and  FIG. 3  for the instance of a three-course embodiment, the staggered placement of the shingles provides a weather-resistant structure that simulates the random shingled appearance of a hand-shingled wall. A first, left end shingle  52  of the lowermost course has a recessed left edge  53  that is laterally recessed or inset so that first shingle  52  does not extend to the left side edge  54  of the base. A second, right end shingle  55  of the lowermost course has a right edge  56  that extends or protrudes laterally beyond right side edge  57  of the base. In the second course of shingles  43 , the end shingles are reversed in their inset and extension with respect to the side edges of the base. Thus, a third, left end shingle  58  of the middle course extends or protrudes laterally beyond left side edge  54  of the base while a fourth, right end shingle  59  is recessed with respect to edge  57  of the base. Similarly, the shingles in the top course of shingles are again reversed so that a fifth, left end shingle  60  is laterally recessed while a sixth, right end shingle  61  extends laterally beyond the respective side edges of base  32 . These principles of interweaving, explained here in the instance of three courses, apply equally across single course and multiple course embodiments.  
      Preferably, the distance to which the end shingles in any course are laterally inset is substantially equal to the distance to which the opposite end shingle of the course extends beyond or protrudes from the base. This structure allows side-by-side shingled siding units, panel assemblies and/or corner assemblies, to mate with each other when placed in abutting relation so that a protruding lower-right end shingle, corresponding to second shingle  55 , on a laterally adjacent panel assembly (not shown) will overlap left side edge  54  of the base and abut against left edge  53  of the first, lower-left end shingle  52 . Similarly, the inset edge of a middle recessed end shingle, corresponding to third shingle  59 , in an adjacent panel assembly will receive the protruding edge of the fourth, middle-protruding shingle  58  in the second course. In the third course, the edge of an upper right protruding shingle, corresponding to sixth shingle  61 , will extend beyond right side edge  54  of the base and protrude into abutting relation with the edge of the fifth, upper recessed shingle  60 . This provides overlapping of the shingles in laterally adjacent panel assemblies, thus producing a weather-resistant joint as well as an aesthetically pleasing joint. When assembled in side-by-side relation, the shingled siding units of the present invention make it very difficult to visually determine the location of the vertical joints between adjacent units.  
      One will appreciate that, in order to facilitate installation of adjacent panel assemblies, the lower and middle recessed shingles  52  and  59  may be relatively thick shingles so as to space the respective overlapping protruding shingles  58  and  61  in the course above farther from base  32  than would be the case if all shingles had the same thickness, as is described in U.S. Pat. No. 4,731,970. Thus, respective protruding shingles  58  and  61  are spaced from the base slightly more so that the height dimension between the lower ends of the protruding shingles and the base is somewhat larger than what would otherwise be the case. This permits the protruding shingles of the lower courses (e.g., shingles  55  and  58 ) of adjacent panel assemblies to readily slide underneath the protruding shingles of the respective upper courses (e.g., shingles  58  and  61 , respectively).  
      To facilitate vertical stacking and positioning of adjacent shingled siding units, upper and lower edges  36 ,  47  of the base preferably are constructed to provide a shiplap joint between top-to-bottom abutting adjacent shingled siding units that is easy to assemble and is particularly resistant to water penetration between the shingled siding units from the ambient environment.  
      For example, and as shown in  FIG. 7 , the top edge of each panel of base  32  is formed as an upwardly facing top shoulder  47 , which is generally perpendicular to the surfaces of sheet-like panels of base  32 . Extending away from shoulder  47  is an outwardly facing beveled surface  62  that slopes from the interior face of each panel toward the shingled face of the shingled building unit. The bottom edge of base  32  is formed with a similar shoulder  36  and beveled construction, except that it has a bevel  63  in the reverse direction, namely, an inwardly facing direction. Thus, bottom edge  36  of each base has a beveled surface  63  which runs from the unshingled inner face of base  32  toward the shoulder  36 .  
      When installing the shingled siding units of the present invention on a building structure, the siding units are preferably installed by mounting a row of lower panel assemblies  30  and/or corner assemblies  31  to the building structure (shown in phantom in  FIG. 6 ) and thereafter mounting a row of higher panel and corner assemblies. For example, a lower corner assembly  31   a  is mounted to the building structure before the upper corner assembly  31   b  is mounted thereto. With lower corner assembly  31   a  in place, upper corner assembly  31   b  slides into position so that its lower shoulder  36   b  abuts the top end of uppermost shingles  46   a  in the uppermost or top course of the lower corner assembly. The beveled faces  62   b  and  63   a  are in surface-to-surface contact resulting with a rabbeted joint so that the edge of one board overlaps the one next to it in a flush joint, thus forming a shiplapped joint that is inherently moisture resistant.  
      Referring again to the example of  FIG. 7 , one will appreciate that the shiplapped joint is moisture resistant, especially in the instance of moisture in the ambient environment outside of the shingles. With respect to condensation within ventilation channel  68 , however, the exemplary embodiment of  FIG. 7  has a small shelf-like channel protuberance  70  due to the thickness of uppermost shingle  46   a . Such a shelf-like protuberance may cause stagnation or pooling of a liquid condensate film falling under gravity within the channel such that the condensate accumulates along the protuberance.  
      As an option, a range of embodiments are further configured such that upper and lower edges of the substrate are formed and dimensioned to allow gravity-driven liquid to flows freely across the edges from one upper panel downward to another lower panel. In some embodiments in the range, when a siding unit and another, similarly formed siding unit are mounted in a vertically abutting relation with the similarly formed siding unit elevationally below the siding unit, an uppermost portion of the upper edge of the similarly formed siding unit is elevationally below the lower edge of the siding unit. This configuration avoids, or under practical conditions of material warp and manufacturing non-uniformity at least reduces, forming small shelf-like channel protuberance along joints. As such, these configurations enable a gravity-driven film of liquid to flow freely across the edges of vertically abutted siding or corner units. In other embodiments in the range, each of the edges of the substrate in the vertically abutting relation optionally includes a beveled surface, and the abutting relation is such that portions of beveled surfaces are separated by a vertical gap.  
       FIG. 10A - FIG. 10E  show embodiments that in different ways enable a gravity-driven film of liquid in the ventilation channel to flow freely along the substrate and across abutments towards earth. The figures are schematic in nature, omitting some details as well as exaggerating others for the sake of clarity. Moreover, one will appreciate immediately that the embodiments in the figures are exemplary and many other alternatives are possible in accord with the principles of the invention.  
       FIG. 10A  shows one embodiment of the forming and dimensioning of the upper and lower substrate, or base, edges. Here, as in other figures, substrate or base  32 , lowermost shingle  34   a , uppermost shingle  46   a  beveled surface  62 , substrate lower edge  36 , and ventilation channel  68  are shown, as well as substrate upper edge  101  and uppermost portion of the substrate upper edge  102 . The direction of gravity is also indicated. See the earlier figures for correspondences.  
      Comparing the embodiment shown in  FIG. 7  to that in  FIG. 10 , one can immediately appreciate that substrate lower edge  36  and upper edge  101  have been formed and dimensioned such that, along the surface of substrates  32  facing ventilation channel  68 , a gravity-driven film of liquid would flow freely down a vertical portion of the surface, across the edges, and along beveled surface  62 . As  FIG. 10A  makes clear for this embodiment, the substrate lower edge  36  is not beveled, whereas upper edge  101  includes beveled surface  62 . Also, uppermost portion of the substrate upper edge  102  is elevationally below substrate lower edge  36  of the abutted unit. In contrast, the embodiment of  FIG. 7  has a protuberance  70 , formed by the corresponding uppermost portion of the substrate upper edge being elevationally above the lower edge of the abutted unit.  
      In forming upper edge  101  to include beveled surface  62  as shown, the thickness of substrate  32  is reduced. Advantageously, a bevel angle may be selected which allows such a thickness reduction to substantially match a minimum thickness of lowermost shingle  46   a . Disadvantageously by comparison, not accounting for the small but finite minimum thickness of lowermost shingle  46   a  in the embodiment of  FIG. 7  results in protuberance  70 .  
      In another alternative to forming and dimensioning substrate edges to achieve free-flow of condensates,  FIG. 10B   1  illustrates that the shingles may include an accommodation cut  103  to mitigate or avoid formation of protuberances  70  of  FIG. 7 . Comparing  FIG. 7  and  FIG. 10B   1 , the difference is by including cut  103  in shingle  34   a , the plane parallel relation of the substrate surfaces facing ventilation channel  68  is preserved and there is no protuberance formed in the embodiment of  FIG. 10B  I. The same gravity-driven flow would move freely in the embodiment of  FIG. 10B   1 , flowing across the abutment along surfaces of substrates  32  facing ventilation channel  68 .  FIG. 10B   2  illustrates a similar embodiment in which the cut angles are reversed.  
       FIG. 10C  shows an embodiment where both abutted substrate edges include a beveled surface. In the figure, beveled surfaces  62  have equal bevel angles. As in  FIG. 10A  and  FIG. 10B , a gravity-driven film of liquid would flow freely down the vertical portion of the substrate surface facing the ventilation channel  68 , across the edges  36  and  101  and beveled surfaces  62 . As well, the embodiment in  FIG. 10C  has uppermost portion of the substrate upper edge  102  being elevationally below substrate lower edge  36  of the abutted unit.  
       FIG. 10D  shows an embodiment where both abutted substrate edges include a beveled surface. However, in contrast to the embodiment of  FIG. 10C , bevel angles in  FIG. 10D  are unequal. As in  FIG. 10A -C, a gravity-driven film of liquid would flow freely. In this instance, however, unequal bevel angles may cause a separation of the liquid flow at separation point  105 . Because the separation point overhangs a beveled surface, however, liquid flow would contact the lower panel on beveled surface  62  after a free fall. As in the embodiments in  FIG. 10A  through  FIG. 10C , the uppermost portion of the substrate upper edge  102  is elevationally below substrate lower edge  36  of the abutted unit.  
      The embodiment in  FIG. 10D  also includes outside bevel  104  on a side of the substrate facing the shingles. Such a bevel may be advantageous for accounting for the small but finite minimum thickness of shingles, as discussed above. Even if protuberances are eliminated or reduced by forming and dimensioning the substrate edges as shown, such a bevel on the side of the substrate facing the shingles may be advantageous in laying shingles in a relaxed flat position, even as they overlap as shown in the figure.  
      Finally,  FIG. 10E  shows an embodiment where both of the vertically abutting edges of the substrate have bevels with unequal bevel angles. Moreover, the bevels on the abutting edges face in opposite directions. Bevel  62  faces toward ventilation channel  68 , whereas bevel  63  faces the shingles. Also, the figure shows outward facing bevel surface  63  providing accommodation of the small but finite minimum thickness of shingles. Again, such accommodation may be advantageous in laying shingles in a relaxed flat position, even as they overlap as shown in the figure.  
      As with the embodiment in  FIG. 10D , unequal bevel angles in the embodiment of  FIG. 10E  may cause a separation of the liquid flow at separation point  105 . Because the separation point overhangs a beveled surface, however, reattachment would occur on the beveled surface after a free fall. As was the case with the embodiment in  FIG. 10D , the abutting relation of the substrate surfaces is such that portions of the beveled surfaces are separated by a vertical gap.  
      Turning now to the spacing means, the shingled siding units  30 ,  31  of the present invention include spacing strips mounted to the inner surface thereof, which strips define ventilation channels through which condensation and any accumulated moisture may escape by drainage or evaporation, even after the shingled siding unit is installed on housewrapped or other sheathing of a building structure.  
      As most clearly shown in  FIG. 2  and  FIG. 4 , a plurality of spacing strips  64 ,  65  and  66  are provided on the inner surface of substrate  32  in order to space panel assembly  30  and corner assembly  31  from the building structure (shown in phantom in  FIG. 8 ) upon which the panel and/or corner assemblies are installed. In the illustrated embodiment, the spacing strips are formed of plywood, particleboard or other suitable material and are attached to the base by suitable fasteners such as strip staple  67 . One will appreciate that other fastening means may be used secure the strips to the substrate including, but not limited to, adhesives and the like.  
      Preferably, the spacing strips are approximately one-quarter inch thick, approximately ¾ to 2 inches wide, and extend substantially the height of the respective base. One will appreciate that the dimensions of the strips may vary in accordance with the present invention. For example, the thickness of the strips may range from approximately ⅛ to one inch thick, and preferably between approximately ⅜ to ¾ inch thick, to provide a corresponding similarly dimensioned passageway between the panel assembly and the building structure.  
      The strips may be spaced from the edges of the base or may extend beyond the edges of the base. For example, strips  64  of panel assembly  30  are spaced inward from the side edges of base  32  as shown in  FIG. 2 , while strips  65  extend along and beyond the side edges of corner assembly  31 , as shown in  FIG. 3 . With reference to  FIG. 2 , the illustrated panel assembly  30  includes five spacing strips  64  secured to the inner surface of base  32  in predetermined intervals. One will appreciate that two, three, four or more spacing strips may be utilized. The strips on the panel assembly may be spaced from one another according to industry norms, for example, spaced 16 or 19½ inches-on-center.  
      Advantageously, the spacing strips of the present invention are pre-assembled on the panel and corner assemblies, thus ensuring that the degree of spacing is controlled, consistently reproducible and properly provided. Namely, the shingled building units of the present invention automatically provide ventilation channels for drainage and/or evaporation, requiring no additional work on the part of workers at a job site. Accordingly, the provision of such ventilation channels cannot be neglected or ignored by field workers installing the panels, either by reason of additional labor cost, as the ventilation channels are automatically formed between the shingled siding units and the sheathing to which they are mounted by the workers.  
      In this regard, adjacent pairs of spacing strips, for example, wide strip  65  and narrow strip  66  clearly shown in  FIG. 8 , define a ventilation channel  68  therebetween. Channel  68  provides a passageway through which condensation and any accumulated moisture to escape by drainage or evaporation, even after corner assembly  31  is installed on the sheathing of a building structure (shown in phantom in  FIG. 8 . One will appreciate that adjacent pairs of spacing strips  64  on the inner surface of planar assembly base  32  define similar ventilation channels that provide a similar drainage or evaporation passageway.  
      Preferably, the spacing strips are substantially vertically oriented thus allowing any water on the interior surface of the panel and corner assemblies to drain down toward the bottom of the building structure for drainage or evaporation. One will appreciate, however, that the strips may be obliquely arranged, provided that the strips form downwardly extending channels. One will appreciate that the venting-channel configuration of the present invention provides a series of approximately one-quarter inch airspace passageways between the shingled siding units, that is, between the external sheathing of the building structure panel and the corner assemblies  30  and  31 , which passageways extend continuously from the uppermost row of installed shingled siding unit to the lowermost row of shingled siding units. Such continuous passageways are effective in venting and draining trapped moisture, a leading cause of water damage, material deterioration, from between the shingled siding units and the building structure based on current building practices.  
      It is understood that the ventilation channels of the present invention may be utilized with or without interwoven shingles. For example, in one embodiment of the present invention shown in  FIG. 9 , corner assembly  31   c  is similar to corner assembly  31  described above but includes a straight edge  69  instead of interwoven end shingles. The straight edge configuration allows the corner assembly to be used with similarly straight-edged panels or with panel assemblies that have been trimmed down using a circular saw. In operation and use, corner assembly  31   c  may be installed in substantially the same manner as corner assembly  31  described above.  
      Accordingly, the present invention improves upon known shingled siding units with respect to moisture control and combination with housewrap products at least in that the invention provides improved moisture management between a building exterior and the ambient environment. Spacing means, which are secured to a shingled siding unit or corner assembly, establish a ventilation channel in combination with a building structure. The ventilation channel, in turn, improves moisture drainage and evaporation. Evaporation is improved because air can transit the channel. Drainage is improved because the spaced surfaces of the channel allow liquid condensate to flow to earth. Moreover, in combination with housewrap products, the ventilation channel improves drainage further in that the invention preserves the drainage plane functionality of housewrap from being otherwise reduced by large portions of the drainage plane being in contact with shingles or other siding units.  
      Still further, as an option, the invention improves the free flow of liquid condensate along the ventilation channel by reducing or eliminating shelf-like protuberances that result in stagnation or pooling of liquid. Specifically, the upper edges of siding or corner units are formed and dimensioned such that when similarly formed units are in a vertically abutting relationship a gravity-driven flow of liquid moves freely across the vertically abutted edges.  
      In another aspect, when attached to planar structural surfaces of a building with ringed shank nails, single and multiple course embodiments of the siding and corner units are resistant to strong winds. A single course embodiment is believed to be remarkably so, and may remain attached to a building even as the building structure fails due to aerodynamic loads.  
      While various fasteners may be used to secure the building panels and units of the present invention to a building structure,  FIG. 11  is a side view of a nail  109  that may be specifically configured for use with the shingled unit of the present invention. In some aspects, nail  109  is similar to ringed shank nails that are presently from Maze Nails of Peru, Ill. Nail  109  includes a shank  110 , ribs  111 , head  112 , and tip  113  as indicated in  FIG. 11 . In contrast to a standard nail, the nail in  FIG. 11  has rings, or ribs formed along the shank portion. Such rings provide a markedly greater resistance to nail extraction. On belief, as such a nail is hammered into material, material flows around the rings partially enveloping them. Thus, as compared to a standard straight shank, there is much greater resistance to extraction.  
      In contrast to conventional roofing nails, however, nail  109  of  FIG. 11  may include a blunted tip as opposed to a pointed tip. With cedar or other relatively brittle woods as material for shingles of the siding and corner units, a pointed tip may be less preferable than a blunt tip because a blunt tip may be less likely to contribute to wood splitting. With other materials such as plastics or composites, however, a pointed tip may be preferred over a blunt tip.  
      Also in contrast to conventional roofing nails, nail  109  of  FIG. 111  may include an enlarged head  112 . To enable wind resistance of a shingled siding unit on a planar structural surface such as a wall, head diameters of greater than ⅜ inch are preferred. For comparatively better wind resistance, nail head diameters of greater than or equal to ½ inch are preferred. With such head dimensions, the shingles are less prone to peel from the substrate and siding units are less prone to peel from the building under the action of aerodynamic forces.  
      For convenience in explanation and accurate definition in the appended claims, the terms “up” or “upper”, “down” or “lower”, “inner” and “outer”, “left” and “right” are used to describe features of the present invention with reference to the positions of such features as displayed in the figures.  
      The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents.