Patent Publication Number: US-2007113508-A1

Title: Batten riser

Description:
FIELD OF THE INVENTION  
      The present invention relates to roofs, particularly tiled roofs in which the tiles are supported by battens which are in turn supported by rafters.  
     BACKGROUND ART  
      Such roofs have a slope and the rafters run down the slope and the battens run across the slope. Traditionally the battens are secured to the rafters by means of a fastener such as a nail which has a shank which passes through the batten and into the rafter. Alternatively, the rafters are covered with a sheet of plywood and the nails pass through both the battens and the plywood and thence into the rafters.  
      Since the air below the tiles is to some extent stagnant, on each occasion when the outside air temperature drops, humidity in the stagnant air volume condenses forming moisture which accumulates in the joints formed below the battens. In addition, some moisture may penetrate the layer of tiles. Because the moisture enters the gap between the two wooden members, it is difficult to re-evaporate on the next occasion when the temperature rises and as a consequence the abutting wooden members remain moist at their intersection. This moisture both causes the timber to deteriorate and also tends to corrode the nail or other fastener. This is the prior art illustrated in  FIGS. 1 and 2  of this specification.  
      It is known to attempt to ameliorate the abovementioned problem by the provision of a batten riser which takes the form of a square or rectangular portion of foam material cut, for example, by scissors from a large sheet of the foam material. These square or rectangular pieces are then inserted between the batten and the rafter, or between the batten and plywood, immediately prior to nailing the batten in position. Such batten risers suffer from two problems. Firstly, they are difficult to install because the square or rectangular portion tends to move from its intended position because there is nothing to hold it in place prior to the nail piercing the square or rectangular portion. Secondly, moisture also tends to collect between the upper surface of the batten riser and the batten, and between the lower surface of the batten riser and the rafter, or plywood, since there is no means provided to facilitate the escape of any moisture.  
      The object of the present invention is to substantially overcome, or at least ameliorate the abovementioned problems of moisture retention and inconvenient installation by the provision of a capillary breaking spaced apart rib arrangement which forms a water drainage passage, and a flange which enables the batten riser to be abutted against the batten prior to the installation of the fastener.  
     SUMMARY OF THE INVENTION  
      In accordance with the first aspect of the present invention there is disclosed a batten riser for a roof having a slope, said riser being of substantially planar conformation and sized for insertion between a supporting member and a roof batten which extends above said supporting member, which extends across the slope, and which supports a plurality of tiles arranged in rows to form said roof, wherein said batten riser includes an upwardly extending flange shaped to abut an upslope edge of said batten and said batten riser further includes a base having a plurality of spaced apart downwardly directed ribs with an opening between each pair of adjacent ribs forming a corresponding water drainage passage.  
      In accordance with a second aspect of the present invention there is disclosed a method of draining condensation from between battens and a support member therefor, supporting a roof having a slope, and extending across the slope, said method comprising the step of: 
          i) inserting a batten riser of substantially planar configuration between the batten and said support member,     ii) abutting an upwardly extending flange of said batten riser with an upslope edge of said batten, and     iii) forming at least one water drainage passage between said batten and support member by a plurality of spaced apart ribs which are directed downwardly from a base of said batten riser.        

     BRIEF DESCRIPTION OF THE DRAWINGS  
      A preferred embodiment of the present invention will now be described with reference to the drawings in which: 
           FIG. 1  is a perspective view of a prior art tiled roof, a portion of the roof being cut away to illustrate the battens and rafters thereunder,        

       FIG. 2  is a side view, partially in cross-section illustrating the inter-section between a batten and a rafter in the prior art,  
       FIG. 3  is a view equivalent to  FIG. 2  but illustrating an installed batten riser in accordance with the preferred embodiment,  
       FIG. 4  is an exploded perspective view of the batten riser installation illustrated in  FIG. 3 ,  
       FIG. 5  is a perspective view of the batten riser of the preferred embodiment,  
       FIG. 6  is a planned view of the batten riser of  FIG. 5 ,  
       FIG. 7  is an inverted plan view of the batten riser of  FIGS. 5 and 6   
       FIG. 8  is a front elevation of the batten riser of  FIGS. 6-7 ,  
       FIG. 9  is a rear elevation of the batten riser of  FIGS. 5-8 ,  
       FIG. 10  is a left side elevation of the batten riser of  FIGS. 5-9 , the right side elevation being a mirror image thereof, and  
       FIG. 11  is a view similar to  FIG. 4  and illustrating the installation where the rafters are covered with a sheet of plywood. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)  
      As seen in  FIGS. 1 and 2 , the prior art arrangement is for a dwelling to have a sloping roof  1  formed from tiles  2  which are supported by battens  3  which extend across the slope of the roof and are located above rafters  4  which extend down the slope of the roof.  
      As seen in  FIG. 2 , a fastener in the form of a nail  6  extends through the batten  3  and into the rafter  4 . Although nails are traditionally used, other fasteners such as screws having an elongate shank can be used instead of nails.  
      As explained in the Background Art above, moisture which condenses in the stagnant air space under the tiles  2 , runs down the upper surface of the rafters  4  and into the overlap formed by the intersection of the battens  3  and rafters  4 . As schematically illustrated in  FIG. 2 , this moisture not only causes deterioration of the wood of the batten and rafter, but also corrodes the shank of the nail  6 . As a consequence of this moisture persisting in the overlap, both the overall condition of the roof and its supports deteriorates and the roof is less strong, particularly since uplifting forces on the tiles  2  caused by strong winds tend to move the battens  3  upwardly because the tiles  2  are secured directly to the battens  3 .  
      Turning now to  FIGS. 3 and 4 , in accordance with the preferred embodiment of the invention a batten riser  10  is inserted into the overlap  11  formed by the intersection of a batten  3  and rafter  4 . The flange  16  enables the batten riser  10  to be abutted against the batten  3  prior to installation of the nail  6 . As usual, the batten  3  is secured to the rafter  4  by means of a nail  6 , or other such fastener, which passes through the batten  3  and into the rafter  4 .  
      As illustrated in greater detail in  FIGS. 5-10 , the batten riser  10  of the preferred embodiment has a generally planar body  13  having a substantially central aperture  14  which is preferably generally rectangular but could be of any shape. As seen in  FIG. 4 , the nail  6  passes through the central aperture  14 .  
      In addition, the batten riser  10  has an upwardly extending flange  16  which, as best illustrated in  FIG. 3 , abuts the upslope surface of the batten  3  which is substantially perpendicular to the rafter  4 . In addition, the batten riser  10  has a base  18  to the body  13  and the base is provided with a number of ribs  20  each of which has a generally rectangular transverse cross-section and each of which extends underneath the batten riser  10  in a direction substantially parallel to the longitudinal axis of the rafter (ie in the down slope direction).  
      It will be apparent to those skilled in the roofing arts that the large size of the aperture  14  relative to the overall size of the body  13  means that the surface area of the batten riser  10  which is actually in contact with the underside of the batten  3 , is relatively small. This inhibits any capillary attraction formed between the upper surface of the body  13  and the batten  3 . As a consequence, the amount of water retention between the batten  3  and the batten riser  10  is minimal.  
      In addition, the ribs  20  cause the batten riser  10  to be spaced above the upper surface of the rafter  4 . The spaces  21  between each pair of adjacent ribs, each constitute a water drainage channel which permits any water which may accumulate on the upper surface of a rafter  4  to drain past each batten  3  supported by a batten riser  10 . This allows such water to drain from the lowermost portions of the rafters  4 , rather than accumulate in the overlap between each batten and rafter. In this connection, the ribs  20  constitute a device to break any capillary attraction between the batten riser  10  and its supporting surface.  
      Turning now to  FIG. 11 , the alternative situation where the rafters  4  are covered with a layer formed from co-planar sheets of plywood  8  is illustrated. Here the batten riser  10  of the preferred embodiment is located directly on the plywood  8  (rather than the rafter  4  as illustrated in  FIGS. 3 and 4 ). Again the battens  3  are raised above the supporting wooden member (in this case the plywood  8 ) thereby allowing moisture which either forms on, or drips onto, the plywood  8  to travel unimpeded down slope to be eventually disposed of into a gutter (not illustrated). This drainage is facilitated by the drainage channels formed by the spaces  21  and an absence of capillary attraction between the plywood  8  and batten riser  10 , and between the batten  3  and the batten riser  10 .  
      The foregoing describes only one embodiment of the batten riser of the present invention and two modes of installation. Modifications, obvious to those skilled in the roofing arts, can be made thereto without departing from the scope of the present invention. For example, the batten riser  10  can be moulded from any suitable plastics materials including PVC, polypropylene, polyethylene and the like.  
      The term “comprising” (and its grammatical variations) as used herein is used in the inclusive sense of “including” or “having” and not in the exclusive sense of “consisting only of”.