A roof tile support element that fits between roof tiles and a roofing surface to provide support for the roof tiles, which is compatible with a broad range of roof tiles, is adjustable during installation, and that allows individuals to walk confidently on a tile roof without breaking tiles.

BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates generally to roofing products, and more specifically, to a roof tile support that allows individuals to walk on a tile roof without breaking tiles. 
   2. Description of the Related Art 
   Tile is one of the predominant roofing products in use today because of its many advantages over other roofing systems. Tile has a long life span and provides good weather resistance. A tile roof requires little maintenance and is not subject to rotting or insect damage. Tile is fire safe and is available in many different colors, shapes, and styles. Additionally, cement or concrete tiles are generally lighter and cost less than traditional clay or ceramic tiles and can be used on most roofs without having to provide structural reinforcements for the roof. 
   One of the only disadvantages of a tile roof is that it is difficult to walk on it without breaking tiles. Sometimes it is necessary to walk on a roof to paint the trim, clean windows or gutters, and remove foreign objects. Tile roofs generally cannot take heavy traffic. Careless foot placement or just “heavy feet” can result in broken tiles. Tile is usually placed on a roof with one side secured to the roofing surface, and the other side resting on, and overlapping, another tile. This overlapping creates a space or gap beneath each tile. Stepping on the middle of a tile will likely break it because the tile is not well supported in that location. 
   Usually only professional roofers are able to walk on tile roofs without damaging any tiles. Yet even a professional tile installer must take great care not to break pieces while walking over the tiles. When walking on a roof, professionals have to choose a route carefully across the reinforced and supported section of each tile. They must walk on the butt of the tile where it rests on solid material, usually at the point where one tile overlaps the next. They must avoid stepping in the center of the tiles where the tiles are vulnerable to fracture. They must focus on distributing their weight evenly between both feet, and walking slowly and softly. 
   Some tile manufacturers have attempted to improve the “walkability” of their tiles by adding a small post on the underside of the tile that provides support for when someone steps on the middle of the tile. There are several problems with this approach. First, because the posts are an integral part of the tile and consist of the same brittle material as the tiles, they often break off during delivery, installation, or use. Second, the tiles cannot be packaged as compactly and the volume that the tiles occupy during delivery is doubled, leading to increased shipping and delivery costs. 
   Additionally, tile is laid according to the specific design of an individual roof. Roofers often vary the amount that each row of tiles overlaps the next row in order to cover the roofing surface with uniform rows of tile. A third problem with the posts is that the amount of overlap, or head lap, for those tiles should not be adjusted. By moving a tile forward to increase the head lap, the post does not reach the roofing surface and the tile will rest too low. In this condition, the post is not supporting the tile and the tile is likely to fracture when stepped on. By moving the tile backward to decrease the head lap, the post will be supported higher up on the roof causing the tile to rest too high. In this condition, the post is likely to snap off under a person's weight and the tile is just as likely to break as if there were no post at all. 
   Some tile manufacturers have introduced different support structures that are permanently attached to their tiles. The biggest problem with these tile structures is their lack of flexibility. As mentioned above, roofers need to be able to adjust the head lap of the tiles to conform to the dimensions and shapes of custom roofs. These pre-supported tile structures require precise alignment and cannot be easily modified by the installer to fit the shape of the roof. Additionally these tile structures are sometimes expensive and are not available in as many colors and styles as the individual roof tiles. 
   SUMMARY OF THE INVENTION 
   The present invention recognizes the desirability of being able to walk on a tile roof with confidence that the tiles will not break. The present invention satisfies the need for a roof tile support element that is compatible with a broad range of roof tiles, is adjustable during installation, and that allows individuals to walk confidently on a tile roof without breaking tiles. 
   In one embodiment of the present invention, a support element fits between roof tiles and a roofing surface to provide support for the roof tiles. Preferred embodiments of the present invention further include roof tile support systems and methods for installing roof tile supports. 
   In one embodiment of the present invention, a support element is preferably wedge-shaped to correspond to the space between the tiles and the roofing surface and to provide support under as much of the tile as possible. The wedge-shaped support element is preferably made of expanded polystyrene so that it is lightweight, durable, semi-compressible, fire safe, inexpensive and easy to manufacture and install. Roof tiles placed on the wedge-shaped support element are preferably supported by the support element, and rest on the back end portion of the next lower course of tiles. This allows downward forces acting on a tile to be distributed over the tile and through the support element to the roofing surface. This distribution of the forces prevents the tile from breaking. 
   Support elements are preferably independent of the roof tiles. Individual support elements can be mass-produced for use with different, but similar, kinds of tile. Additionally, during installation the roof tiles can be adjusted forward or backward with respect to the support element in order to increase or decrease the head lap of the tiles. Support elements that are not attached to tiles are more cost effective in terms of packaging and delivery than combined structures. 
   Another preferred embodiment of the invention is a roof tile support system with a roofing surface, roof tiles, and support elements. The support elements are preferably positioned between the roofing surface and the tiles in a manner suitable for distributing and transferring concentrated forces acting on the tiles more evenly to the roofing surface. Distributing and transferring the forces increases the load capacities of the tiles and improves the walkability of the roof. 
   One of the preferred methods for installing roof tile supports comprises placing a support element on a roofing surface, placing a roof tile over the support element, and securing the roof tile to the roofing surface. 


   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view, partly in cross-section, of a roof tile support system illustrating one embodiment of the present invention; 
       FIG. 2  is a perspective view of a portion of the roof tile support system of  FIG. 1 ; 
       FIG. 3  is a perspective view, partly in cross-section, of another embodiment of a roof tile support system; 
       FIG. 4  is a perspective view of a roof tile support element according to one embodiment of the present invention; 
       FIG. 5  is a perspective view of another embodiment of a roof tile support element; 
       FIG. 6  is a perspective view in cutaway of an alternative embodiment of a roof tile support element for the roof tile of  FIG. 3 ; 
       FIG. 7  is a perspective view of a packaging assembly illustrating a method of packaging a plurality of roof tile support elements. 
   


   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   One embodiment of the invention is illustrated in  FIG. 1 , in which a roof tile support system  10  is shown covering a portion of a roof. A roofing surface  12  is shown. Several roof tile support elements  14  are shown resting on the roofing surface  12 . Finally, several roof tiles  16  are shown resting on the roof tile support elements  14  and the roofing surface  12 . 
   Preferably, the roofing surface  12  is a structure capable of receiving and supporting a tile roof. In a preferred embodiment of the invention, the roofing surface  12  is a supported plywood deck  18  covered by tarpaper  20 . In other embodiments of the invention, the roofing surface  12  also includes battens to which roof tiles  16  are attached. In the preferred embodiment of  FIG. 1 , one end of the roofing surface  12  has a wooden cross member  22  to which the eave metal  24   a,b  of the roof is attached. One skilled in the art will be familiar with other variations or combinations of materials constituting a roofing surface  12 . 
   In a preferred embodiment of the invention, a roof tile support element  14  fits between roof tiles  16  and a roofing surface  12  to provide support for the roof tiles  16 . Preferably, a support element  14  is wedge-shaped to correspond to the space between the tiles  16  and the roofing surface  12  and to provide support under as much of the tile  16  as possible. The support element  14  is preferably made of expanded polystyrene so that it is lightweight, durable, semi-compressible, fire safe, inexpensive and easy to manufacture and install. Alternatively, the support element  14  may be made of other materials such as foam, rubber, plastic, or any other material which provides sufficient support when used as described herein. 
   The support element  14  preferably rests directly on the roofing surface  12 . Support elements  14  are preferably arranged in rows on the roofing surface  12 . A support element  14  in a row is preferably one or two inches away  26  from the next support element  14  in the row. The space  26  between the support elements  14  is preferred to facilitate water drainage on the roof. 
   In a preferred embodiment of the invention a roof tile  16  is a roof-covering product that is brittle, subject to fracture, or likely to break under the weight of an individual walking on an installed roof. In a particular preferred embodiment illustrated in  FIG. 1 , the roof tile  16  is a lightweight concrete tile in a shake or slate profile. The roof tile  16  has a back end portion  28  which is preferably supported by the thinner end of the support element  14  such that it does not contact the roofing surface  12 , thereby “floating” the roof tile  16  above the roof surface  12 . A middle portion  30  of the roof tile  16  preferably rests on the support element  14 . A front end portion  32  of the roof tile  16  overlaps the back end portions  28  of the tiles  16  of the next lower course. In this configuration, each roof tile  16  effectively floats on the support element  14 . This allows for loads to be evenly distributed across the tiles  16 , support elements  14 , and roof surface  12  respectively. 
   In an alternative embodiment, the support element  14  may have a triangular cross-section as illustrated in  FIGS. 3 and 4 . In this embodiment, the roof tile  16  may be positioned on the support element  14  such that the back end portion  28  rests on the roofing surface  12 . In this particular embodiment, the roofing tile is partly supported by the roofing surface  12  as well as by the support element  14 . 
   In a preferred embodiment shown in  FIG. 2 , roof tiles  16  placed on the wedge-shaped support element  14  preferably rest on the next lower course of tiles  16 . This allows downward forces acting on a tile  16  to be distributed over the tile  16  and through the support element  14  to the roofing surface  12 . This distribution of the forces prevents the tile  16  from breaking. Preferably, roof tiles  16  placed on the support elements  14  will rest directly on the next lower course of tiles  16 . 
   The roof tiles  16  are preferably secured in place using nails  36  appropriate for use with roof tiles  16 . As illustrated in  FIG. 2 , the nails  36  may pass through both the roof tile  16  and the support element  14 . In other embodiments, the nails  36  may only pass through the roof tiles  16 . Support elements  14  are preferably independent of the roof tiles  16 . During installation, roof tiles  16  can be adjusted forward or backward with respect an independent support element  14  in order to increase or decrease the amount of overlap  38  of the tiles  16 . 
   Another preferred embodiment of the invention is illustrated in  FIG. 3 , in which a roof tile support system  10  is shown covering a portion of a roof. A roofing surface  12  is shown comprising a roof deck  18  and a layer of tarpaper  20 . One end of the roofing surface  12  has a wooden cross member  22  to which the eave metal  24   a  of the roof is attached. Several wedge-shaped roof tile support elements  14  are shown resting on the roofing surface  12 . Finally, a roof tile  16  is shown resting on a roof tile support element  14 . 
   In a particular preferred embodiment illustrated in  FIG. 3 , the roof tile  16  is a lightweight concrete tile in a barrel profile. The roof tile  16  has a back end portion  28  that preferably rests on the support element  14 . A middle portion  30  of the roof tile  16  preferably rests on the support element  14  as well. A front end portion  32  of the roof tile  16  is shown overhanging the edge of the roof. Generally, in higher rows, the front end portion  32  of a roof tile  16  preferably overlaps the back end portions  28  of the tiles  16  of the next lower course. 
   The barrel roof tiles  16  that are placed on the wedge-shaped support elements  14  are preferably supported by the support elements  14 , but rest directly on the next lower course of tiles  16 . Preferably, roof tiles  16  placed on the support elements  14  will rest on the back end portion  28  of the next lower course of tiles  16 . 
   In another preferred embodiment, as shown in  FIG. 6 , the support element  14  has arched sections  72  corresponding to the barrel sections  70  of the roof tiles. The arch sections  72  may be integrally formed with the rest of the support element  14  such that a shape similar to the underside of the barrel roof tile  16  is created. Alternatively, the arch sections  72  may be separate or detachable from the rest of the support element  14 , in which case the arch sections  72  may be held in place by glue, tape, or simply by friction.  FIG. 6  shows the support element with a triangular cross-section, however, a support element having features and advantages of the present invention may also have a quadrilateral cross-section in combination with the arch sections  72  described above. 
   One embodiment of the invention, shown in  FIG. 4 , is a roof tile support element  14 . Support elements  14  are preferably independent of roof tiles. Individual support elements  14  can be mass-produced for use with different, but similar, kinds of tile. The support element  14  is preferably made of expanded polystyrene. The support elements  14  are preferably cut from a large block of expanded polystyrene with a hot wire. 
   In a particular preferred embodiment shown, the support element  14  is wedge-shaped. The wedge-shaped support element  14  has a triangular cross-section  40 . The support element preferably has a top surface  56  for contacting roof tiles and a bottom surface  58  for contacting a roofing surface. Preferably, the large surface areas on the top and bottom of the support element are in contact with substantial portions of the roof tiles and the roofing surface. The support element  14  is preferably long enough to support between three and five roof tiles. Other embodiments, however, may support more or fewer tiles. The support element  14  is preferably four feet long  42 . 
   The width  44  and the height  46  of the support element  14  will vary depending on the specific shape and size of the roof tiles with which the support element is designed to be compatible. Preferably, the height  46  at the front end  48  of the support element  14  will be about 0.125″ higher than the height of the back end portion of a roof tile on the next lower course. The width  44  of the support element  14  is preferably wide enough that its bottom surface  58  covers a majority of the roofing surface directly below the middle portions of corresponding roof tiles. The width  44  of the support element  14  is preferably wide enough that its top surface  56  contacts a majority of the surface under the middle portions of corresponding roof tiles. 
   For example, a roof tile support element  14 , with a triangular cross section  40 , may be designed to be compatible with roof tiles that are approximately 15″ long, 12″ wide and 1″ tall. The front end portion of the roof tile may be intended to overlap a lower course of tiles by about 3″ with the back end portion of the tile intended to be in contact with a roofing surface for about 1″. The front end portion of the roof tile may be supported above the back end portion next lower course of roof tiles. According to one embodiment as shown in  FIGS. 1 and 2 , the distance  34  that a roof tile  16  should be supported above the next lower course of tiles  16  is related to the compressibility of the support element  14 . When someone walks on the tile roof supported by support elements  14  with a triangular cross section, the support element  14  will be compressed and the distance between the upper and lower tiles  16  will decrease. 
   A roof tile support element  14  designed to be compatible with such a tile could be four feet long  42 , 11″ wide  44 , and 1.125″ tall  46 . In such an arrangement, four tiles could be placed over the support element  14 . The bottom surface of the support element  14  would be covering a majority of the roofing surface directly below the middle portions of the four roof tiles. The middle portions of the lower surfaces of the four roof tiles would be in contact with the top surface  56  of the support element  14 . A majority of the surface area under the roof tile, that is not overlapping lower tiles or in contact with the roofing surface, would be supported by the support element  14 . 
   Other embodiments of the support element  14  may effectively support roof tiles by contacting less than a majority of the surface under the middle of the tiles. Some tiles with barrel profiles, for example, may be supported sufficiently even though the top surface of the support element may not contact a majority of the bottom surface of the middle of the tiles. Preferably, support elements contact and support roof tiles at selected locations on the underside of the tiles to generally provide support to the otherwise unsupported middle sections of the tiles. 
   In a similar preferred embodiment shown in  FIG. 5 , the support element  14  is again wedge-shaped. However, the wedge-shaped support element  14  has a quadrilateral cross-section  50  rather than a triangular cross-section. The support element preferably has a thicker front end  48  and a thinner back end  60 . The support element preferably has a top surface  56  for contacting roof tiles and a bottom surface  58  for contacting a roofing surface. Preferably, the large surface areas on the top and bottom of the support element are in contact with substantial portions of the roof tiles and the roofing surface. 
   A support element with a quadrilateral cross-section  50  may be preferable with certain shapes, sizes or types of tiles. In one preferred embodiment, the support element  14  is compatible with roof tiles requiring battens on the roofing surface. In other embodiments the support element  14  is compatible with roof tiles which may or may not require battens. 
   The thinner back end  60  of a support element  14  can be placed adjacent to a batten. The height  62  of the thinner back end  60  of the support element  14  is preferably the same height or slightly higher than the batten. Preferably, the height  46  at the thicker front end  48  of the support element  14  will be about the same as the height of the back end portion of the roof tile and batten of the next lower course. 
   The width  44  of the support element  14  is preferably wide enough for the bottom surface  58  of the support element to contact and cover a majority of the roofing surface under the middle portions of the corresponding roof tiles. Additionally, the width  44  of the support element  14  is also preferably wide enough that its top surface  56  contacts a majority of the surface under the middle portions of corresponding roof tiles. However, as noted previously, other embodiments may effectively support the tiles by contacting less than a majority of the surface under the middle of the tiles. 
   In one specific preferred embodiment, a support element  14  is compatible with an Eaglelite Malibu tile to be installed on a roofing surface with battens. The support element  14  for use with this type of tile is four feet long  42  and 11″ wide  44 . The height  46  of the thicker front end  48  is 1.875″ and the height  62  of the thinner back end  60  is 1″. 
   In another preferred embodiment, a support element  14  is compatible with a Monier Cedarlite tile. The support element  14  for use with this type of tile is four feet long  42  and 7.5″ wide  44 . The height  46  of the thicker front end  48  is 1″ and the height  62  of the thinner back end  60  is 0.375″. One skilled in the art will be familiar with these manufacturers and tiles. 
     FIG. 7  illustrates a preferred packaging assembly  52  of roof tile support elements  14 . A number of support elements  14  are shown arranged into a bundle  52 . The support elements  14  are preferably stacked in an alternating fashion such that each overlaying element  14  is turned 180° relative to the adjacent elements  14  stacked thereby. The support elements  14  are preferably bound with a plastic wrap  54  or some other method of binding. In another preferred embodiment the support elements  14  are packaged in bags. Support elements  14  that are independent of roof tiles are more cost effective in terms of packaging and delivery than combined structures. 
   A preferred method of installing roof tile supports, comprises placing a support element on a roofing surface, placing a roof tile over a support element, and securing the roof tile to the roofing surface. Embodiments of the invention vary depending on the type of support elements and roof tiles used. In one preferred method, as seen in  FIG. 3 , the roof tile  16  is placed so that it is in contact with, and rests completely on, the support element  14 . In another embodiment, an example of which is shown in  FIG. 1 , the roof tile  16  is placed so that it rests on the support element  14  and the roofing surface  12 . In another method, the roof tile  16  may be placed so that it rests on a support element  14  and the tiles  16  of the next lower course. In still another embodiment, the roof tile  16  may be placed so that it rests on the roofing surface  12 , the support element  14 , and the tiles  16  of the next lower course. 
   Preferably, the roof tiles  16  are placed over the support elements  14  and then secured to the roofing surface using roofing nails  36 , such as shown in  FIG. 1 . In a preferred method of installation the nail  36  passes through both the roof tile  16  and the support element  14  and into the roofing surface  12  to secure the tile  16 . In another preferred method, the nail  36  passes through the tile  16  and into the roofing surface  12  and the weight of the tile  16  acts to secure the support element  14 . One preferred method of installing roof tile supports  14  includes positioning a second support element  14  in a row next to a first support element  14 , leaving a gap  26  between the two elements  14  to facilitate water drainage on the roof. Alternatively, water drainage may be further facilitated by forming grooves  13  in the bottom surface of the support elements  14 , e.g. the surface which contacts the roofing surface  12 . Such grooves  13  would allow water to flow underneath each support element  14  as well as between them. 
   Although preferred embodiments of the present invention have been described herein, it will be understood by those of ordinary skill in the art that certain obvious modifications and departures from these embodiments can be made without departing from the spirit or essential characteristics of the invention.