Abstract:
A roof planter comprising growth media capable of sustaining a desired vegetation, a sack retaining a quantity of the growth media, the sack being formed of moisture permeable material that is capable of retaining the growth media, the sack having an opening capable of accepting the growth media, and a pad in association with the sack and capable of separating the sack from the top of a roof. When the desired vegetation is planted in the growth media being retained by the sack, and the pad is positioned between the sack and the roof, the vegetation may grow in the sack on the roof without causing damage to the roof. Further, a fabric roof planter is disclosed having a sack that is fashioned with vertical sidewalls to facilitate a predictable footprint; handles to facilitate horizontal transport; and sealable windows to facilitate the rapid planting of vegetation in the growth media retained by the sack.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation-in-part of U.S. application Ser. No. 11/357,609, filed Feb. 17, 2006, for the invention of Kelly William Luckeft and Victor Jost entitled “Fabric Roof Planter,” and derives and claims priority from that application, which application Ser. No. 11/357,609 is fully incorporated by reference herein. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not Applicable. 
       BACKGROUND OF THE INVENTION 
       [0003]    Green roofs, roof gardens, eco-roofs all refer to the planting of vegetation on the roof surface of building structures. The principle of green roofs has been widely used in Europe for several decades. Roof top vegetation substantially reduces storm water run off, solar heat gain, and thermal transfer through the roof. In addition, large vegetated surfaces help to replenish oxygen through photosynthesis. Though the benefits are many, the typical green roof costs are several times that of most roofing systems. The high price of typical green roof construction emanates from costly waterproofing procedures, extensive drainage layers, soil of depths ranging from eight inches to twenty four inches, and additional required structural construction to support resulting increased weight. Repairs to the roofing membrane are extremely expensive due to the large quantities of material that must be moved to access the waterproofing layer. 
         [0004]    Roof planters have recently been developed that can be placed atop standard roofs without the need for special roof construction. These include modular and full system planters in which the plants are housed in rigid containers atop the roof. However, these planters still have cost disadvantages. In particular, the material handling aspect of green roof installation continues to be problematic. Large amounts of soil (also known as “growth media”) are needed for plant growth on rooftops. Transporting the required soil from the source to the project rooftop is difficult and expensive. While pre-planted module planters are a significant improvement over previous methods of green roof installation, they are heavy and the cost of such module planters presents a barrier that many projects are unable to overcome. Moreover, it is desirable that planters installed on a roof be movable in order to provide access to the roof under the planters for inspection and maintenance of the roof. Hence, a more mobile and cost-effective planter is desirable. In addition, there is resistance to using green roof systems due to the need for installation methods that vary substantially from techniques and methods traditionally used in the roofing industry. Hence, it is desirable to have a roof planter that can be installed by more traditional methods commonly used in the roofing industry. 
         [0005]    In addition, each roofing manufacturer markets and sells roofing material of differing compositions, and each manufacturer offers warranties on its new roofing material. During construction of a roof, it is often desirable and/or necessary for the laborers to tread upon newly laid roofing. To minimize trauma to the newly laid roofing and to prevent the voiding of warranties on the newly laid roofing, each manufacturer markets and sells walk pad material that can be placed upon the newly laid roofing to allow laborers to walk atop the newly laid roofing with minimal damage and without voiding the roofing manufacturer&#39;s warranties. Each roofing manufacturer&#39;s walk pad is composed of material specifically engineered for use on that same manufacturer&#39;s roofing material. The use of any other walk pad or any other material on the roof risks damage to the roofing material and voiding of the manufacturer&#39;s warranty. This can present yet another major obstacle to the acceptability of green roof systems. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0006]    The illustrative embodiments of the present invention are shown in the following drawings that form a part of the specification: 
           [0007]      FIG. 1  is a perspective view of an embodiment of the fabric roof planter, the fabric roof planter setting on a pad atop a roof surface; 
           [0008]      FIG. 2  is a macro view of the material used to construct an embodiment of the fabric roof planter; 
           [0009]      FIG. 3  is a perspective view of a portion of the top of an embodiment of the fabric roof planter showing a cross-shaped slit having plants rooted in growth media of the planter; 
           [0010]      FIG. 4  is a perspective view of a pallet upon which are stacked multiple fabric roof planters having the embodiment; 
           [0011]      FIG. 5  is a perspective view of the sack of the first embodiment of the fabric roof planter, wherein the sack is shown open at one end; 
           [0012]      FIG. 6  is a perspective view of multiple fabric roof planters stacked atop a pallet; 
           [0013]      FIG. 7  is a perspective view of an alternate embodiment of the fabric roof planter having a generally rectangular shape, a sealable window for the placement of vegetation in the planter, and handles, the planter window being shown in an open position; 
           [0014]      FIG. 8  is a perspective view of yet another alternate embodiment of the fabric roof planter having a generally rectangular shape, a plurality of sealable windows for the placement of vegetation in the planter, and handles, the planter being shown with some of the windows open and some closed; 
           [0015]      FIG. 9  is a perspective view of an embodiment of the fabric roof planter having handles at each end and being carried by the handles by two persons; 
           [0016]      FIG. 10  is a perspective view of a plurality of fabric roof planters of an embodiment having a generally rectangular shape, where the planters are placed flat upon a surface in a close-packed configuration; 
       
    
    
       [0017]    Corresponding reference characters indicate corresponding parts throughout the several views of the drawings. 
       DETAILED DESCRIPTION OF INVENTION 
       [0018]    In an illustrative embodiment ( FIG. 1 ), the fabric roof planter  10  is shown positioned on a roof upper surface  11 . The planter  10  comprises a fiber sack  12 , nine slits  14  in the sack  12 , growth media  16  retained in the sack  12 , and a protective pad  20  positioned between the sack  12  and the roof surface  11 . The roof surface  11  comprises a membrane M atop the surface  11 . The surface  11  may be of virtually any profile, including for example, flat, pitched, curved or otherwise uneven. The sack  12  is formed of a moisture permeable material, preferably a high durability plastic fiber, and even more preferably knitted high density polyethylene  30  (see  FIG. 2 ), with a weave that is tight enough to retain the growth media  16  in the sack  12  while allowing moisture to pass through the sack  12 . This construction also keeps sharp particles from spilling out of the sack  12  onto the roof surface  11  and into roof drainage systems. As shown in  FIGS. 1 and 3 , the vegetation  18  is planted in the growth media  16  through the slits  14  in the sack  12 . The slits  14  may be preformed in the sack  12 , prior to filling with the growth media  16 , or the slits  14  may be cut into the sack  12  at any time thereafter to accommodate planting the vegetation  18  in the planter  10 . 
         [0019]    The pad  20  ( FIG. 1 ) is formed of a material that is compatible with the roof surface  11  and intended to provide a buffer between the sack  12  and the surface of the roof  11  to protect the roof membrane M. Accordingly, the pad  20  may be composed of a variety of materials, including for example: roof walk pad material; roof shingle material; rubber; roof paper; plastic; foam; wood; cloth; and geo-textile. Preferably, the pad  20  is formed of a geo-textile material that is known to be compatible with most roof membrane materials. The pad  20  is therefore positioned between the sack  12  and the upper surface of the roof  11  such that the sack  12  does not substantially contact the surface  11 . The pad  20  may alternatively be attached to the sack  12 , or may form a portion of the sack  12  (see  FIG. 4 ). In such a configuration, the pad portion  13  of the sack  15  forms the primary contact between the planter  10  and the surface of the roof  11 . Of course, one of ordinary skill in the art will recognize that a protective pad  20  may not be required for all applications, and that the planter  10  may be configured without the pad  20 . 
         [0020]    The sack  12  of  FIG. 1  is formed by sealing two generally rectangular shaped sheets  22 ,  24  ( FIG. 5 ) of moisture permeable material together along each of three sides of said sheets, thereby forming a pocket between the sheets  22 , 24  that is capable of retaining the growth media  16 . The sheets  22 , 24  may be sealed together in a number of ways well understood by one of ordinary skill in the art, including but not limited to sewing, heat sealing, gluing and clamping. The remaining fourth sides of each of the sheets  22 ,  24  define an opening  26  in the sack  12 . The growth media  16  is placed in the sack  12  through the opening  26 . The opening  26  is then also sealed shut, which may also be accomplished in a number ways well understood by one of ordinary skill in the art, including, for example, tying, sewing, heat sealing, gluing and clamping. 
         [0021]    The sack  12  is formed of a fabric  30  as depicted in  FIG. 2 . The fabric  30  is constructed of a weave that is capable of retaining the desired growth media  16  while being moisture permeable. The fabric  30  is preferably constructed of nylon material, and even more preferably a knitted high density polyethylene. Of course, the fabric  30  that forms the sack  12  may be of differing configurations and formed of different materials depending on the specific formulation of growth media  16  that will be placed in the sack  12 . That is, the smaller the granulation of the desired growth media  16  to be placed in the sack  12 , the tighter the weave that is required in the fiber  30 . Conversely, the larger the granulation of the desired growth media  16  to be placed in the sack  12 , the more relaxed can be the weave in the fiber  30 . Moreover, the sack  12  can alternatively be constructed, at least in part, of a non-porous material, such as for example plastic (not shown), if the sack  12  has holes, slits or other such openings in the material that are sized and/or positioned on the sack  12  such that they are capable of retaining the growth media  16  while allowing for the penetration of moisture. 
         [0022]    The sack  12  of the present embodiment of the planter  10  as shown in  FIGS. 1 ,  2  and  5 , is constructed of two sheets  22 , 24  of fabric  30  where three sides of each of the sheets are sewn together. Of course, the sack  12  could be constructed in alternate ways. For example, the fabric  30  could be produced in the shape of a tube and thereby only require one end to initially be sealed or sewn together to form the sack  12 . In any event, once the sack  12  is formed, the user has a number of options in application of the planter  10  upon a roof surface  11 . 
         [0023]    The sack  12  may be shaped in a variety of configurations in all three dimensions, taking for example the shape of a box, a tube, or a cup. Hence, the roof planter  10  may be a shape other than rectangular or square, such as, round, oval, triangular, or any other shape desired by the user. Significantly, a unique feature of the present disclosure is the fabrication of a fabric roof planter sack having vertical sidewalls or surfaces. In most instances, a generally vertical edge will form where the edges of the sidewalls or surfaces meet. In one such embodiment, the sack  12 ′ is formed in a boxlike shape as depicted in  FIGS. 7-10 . Referring to  FIG. 7 , it can be seen that this embodiment of the sack has a generally rectangular upper surface  100  with preferred dimensions of 24 inches in width and 30 inches in length, four vertical and generally rectangular side surfaces  101 ,  102 ,  103  and  104 , each having a preferred height of 4 inches, and a corresponding generally rectangular bottom surface  105  with preferred dimensions of 24 inches in width and 30 inches in length. Each of the surfaces  100 - 105  are shaped and configured in conjunction with the shape of the sack  12  to be generally flat when the sack  12  is filled with growth media  16 . Of course, due to the flexible nature of the material comprising the sack  12 ′, the surfaces  100 - 105  will distort without some form of support such as when the sack  12 ′ is filled with growth media  16 . 
         [0024]    Although more costly and requiring custom fabrication, a fabric roof sack having vertical side walls, or more particularly, the boxlike shape of the sack  12 ′ provides a substantial advantage in roof planter applications over traditionally shaped sacks, which are generally tubular in shape. The roof coverage of the planters drives nearly all estimate and installation functions for a roof job, including designing, bidding, costing and installing roof planters. Due to the highly variable shape of traditional sacks when used as fabric planters, the coverage estimates are often inaccurate and can vary greatly on every job. For example, estimating fabric roof planter coverage using traditional sacks would require inputting ranges of 18 to 22 inches for the width of each sack and 28 to 32 inches for the length of each sack. This translates into a high risk of shortages and/or overages and the negative resulting costs and waste associated with such inaccuracies. Further, using traditional sacks, each job requires manipulation and manual placement and often replacement of sacks to arrive at a uniform and aesthetically pleasing arrangement of roof planters. In contrast, the boxlike shape of the sack  12 ′ provides a specific footprint for each sack  12 ′ and a resulting higher accuracy for all aspects of the job design, estimate and installation. Of course, the addition of even one such vertical sidewall or side surface (e.g.  101 - 104 ) to a fabric roof planter will provide an incremental improvement in the accuracy of the job design, estimate and installation. 
         [0025]    Further, the roof planter  10  may additionally incorporate features to aid in handling the planter, such as handles and grips. For instance, the sack  12  or the pad  20  may be shaped to incorporate handles, grips or grip holes, or such features may simply be attached to the roof planter  10 . In this regard, the sack  12 ′ is constructed with a pair of carrying straps or handles  105  attached to each of two opposite side surfaces  102  and  103 , as shown in  FIGS. 7-8 . The pairs of handles  105  are preferably constructed of the same material as the sack  12 ,  12 ′, but may be constructed of any variety of materials that can be attached to the opposite side surfaces  102  and  103  with sufficient strength to lift the sack  12 ′ when filled with growth media  16  without failure. Although formed of a single length of material sewn at each end and in the middle to the side surfaces  102  and  103 , each of the individual handles in the pairs  105  can alternately be formed separately, so long as they are positioned outwardly from the center of the side surfaces  102  and  103 . The individual handles in each pair of handles  105  are spaced apart from one another along the opposite side surfaces  102  and  103 , such that when the sack  12 ′ is raised by the handles  105 , the sack  12 ′ can be carried in a generally flat orientation as illustrated in  FIG. 9 . The handles  105  can also be alternately attached to the sack  12 ′ at different positions. For example, the handles  105  can be attached to the upper surface  100 , the lower surface  104 , the seam between the upper surface  100  and one or more of the side surfaces  101 - 104 , or the seam between the lower surface  105  and one or more of the side surfaces  101 - 104 . 
         [0026]    This is significant in that when the sacks  12 ′ are filled with growth media  16 , and then transported, handled and then placed or positioned on a roof, the growth media  16  can readily shift within the sack  12 ′ from one portion of the sack to another. This results in the undesirable conditions of uneven distribution of the growth media in the sack  12 ′. Uneven distribution of the growth media  16  in the sack  12 ′ leads to thin spots in the sack  12 ′ that present an unattractive surface of the sack  12 ′ when positioned on a roof, and can adversely impact the short and long-term growth potential of the vegetation planted in the growth media  16  due to variations across the media  16  in water retention capability, thermal insulation and nutrient availability. The handles  105  provide a desirable mechanism to enable persons handling the sacks  12 ′ to keep the sacks  12 ′ relatively horizontal during filling, stacking, storage, distribution and positioning on a roof, to thereby minimize the undesirable shifting of the growth media  16  within the sacks  12 ′. The handles also provide a surer grip to the sack  12 ′ and eliminates the need to wear gloves during handling of the sacks  12 ′, which gloves were highly desirable when handling roof planter sacks without any such handles  105 . 
         [0027]    The sack  12 ′ is further constructed with a sealable window  110 . ( FIG. 7 ). The window  110  comprises a generally rectangular opening  112  in the upper surface  100  of the sack  12 ′ and a closure  114  attached to one end of the opening  112 . The closure  114  has the same general shape of the opening  112  to enable the closure  114  to seal against the opening  112  to close the sack  12 ′ to generally prevent inadvertent leaking of growth media  16  from the sack  12 ′ during activities such as shipping, handling or installation. While the opening  112  shown in  FIG. 7  is generally rectangular, the opening can be of nearly any shape and size, and can be positioned at any location on the upper surface  100 . In this version of the sealable window  110 , strips of a good and loop materials such as Velcro®  116  are attached along the outwardly facing edges of the opening  112  that are not attached to the closure  114 . Mating strips of Velcro®  118  are likewise attached to the inwardly facing outer edges of the closure  114  that are not attached to the opening  112 . When the closure  114  is properly positioned in contact along the full perimeter of the opening  112 , the Velcro® strips  116  of the closure  114  and the strips  118  of the opening  112  can engage each other and the closure  114  thereby fully shuts the opening  112 . In this embodiment, the closure  114  is constructed of the same material as the sack  12 ′. However, various alternate materials could be used so long as the closure  114  is able to seal against the opening  112  to generally prevent the inadvertent leaking of growth media  16  from the sack  12 ′ as described herein. 
         [0028]    The windows  110 , formed during fabrication of the sack  12 ′, provide a significant improvement over sacks having no preformed sealable opening for the placement of vegetation. When using a sack  12  without a window  110 , installation requires the creation of an opening on the roof. Generally, such openings can be formed with a razor or other such sharp tool, or with a directed flame such as from a small torch. The use of cutting tools and torches on a rooftop can be a dangerous activity. In addition, cutting through the fabric and into the growth media  16 , which is typically highly abrasive, causes the cutting tools to dull very quickly, resulting in frequent changes or sharpening and a very slow process. 
         [0029]    Of course, variations exist with respect to this inventive window  110 . For example, the window  110  may be sealed with a variety of closure materials and mechanisms, such as for example, buttons, zippers, adhesives, snaps and ties. Further, strips of fabric, metal or other material may be interwoven along the edges of the window  110 . In addition, for certain applications it may not be necessary to seal the entire perimeter of the window  110 . For example, in some applications, it may only be necessary to seal the edge of the window  110  opposite the edge along which the opening  110  is attached to the closure  114 , or, alternately, it may only be necessary to seal the edges extending from the opening  110  is attached to the closure  114 . Moreover, it may be desirable to completely remove the closure  114  from the opening  112 , in which case no portion of the closure  114  will be permanently attached to the opening  112 . Rather, the closure  114  and the opening  112  will have mating Velcro® strips to enable the complete removal of the closure  114  from the opening  112 , as shown in  FIG. 8 . While it is not a necessity that the window  110  be resealable once the vegetation  18  is placed in the sack  12 ′, it will be recognized that the use of a closure mechanism such as Velcro® provides the added benefit of multiple uses of the sealing attribute for the window  110 . 
         [0030]    The adaptive nature of the present disclosure provides a substantial improvement over existing roof planters. For example, the sack  12  may be filled with growth media  16  at any time that is most convenient to the user prior to planting the vegetation  18  in the growth media. It may be desirable to fill the sack  12  with growth media  16  at a manufacturing or processing facility and then transport the filled sack  12  and associated pads  20  to a job site where they will then be positioned on the upper surface of a roof  11 . The vegetation  18  may be planted in the growth media  16  prior to, or after, the planter  10  is positioned on the roof  11 . Alternatively, the sack  12  may be delivered to a job site empty, and the growth media  16  may be placed in the sack  12  at the site. Again, the vegetation  18  may be planted in the growth media  16  prior to, or after, the planter  10  is positioned on the roof  11 . In yet another alternative, both the growth media  16  and the vegetation  18  can be added to the sack  12  after the sack  12  is positioned on the pad  20  on the surface of the roof  11 . 
         [0031]    Further, quantities of the sacks  12  can be transported in bulk prior to filling with the growth media  16 , or alternatively, quantities of the sacks  12  can readily be transported after already being filled with growth media  16 . In the latter case, the sacks  12  may be conveniently stacked in groups or even on a pallet  32  for ease of conventional transport. (see  FIG. 6 ). In this way, the sacks  12  can be readily stacked on pallets in the same manor as soil suppliers currently handle other products. The pre-packed sacks  12  provide an attractive alternate to the cranes and hoisting equipment necessary to hoist dump truck loads of material to the rooftop as pallets of pre-packed sacks  12  can be delivered to loading docks and conveyed to the rooftop using freight elevators. By assimilating into the existing operational infrastructure of the soil suppliers in this manner, little additional set up costs are incurred using the present disclosure. 
         [0032]    In contrast with conventional rigid roof planter systems, which can only be shipped in quantities that cover approximately 64 square feet per standard pallet, the pre-packed sacks  12  can be shipped in quantities that will cover approximately 218 square feet per standard pallet. This increased shipping capacity reduces transport costs at each phase of distribution; warehousing, shipping to the project, and loading to the rooftop. Additionally, this concept allows for pre-packed soil to be easily warehoused and stocked without consideration given to shipping and storage duration or weather conditions. Moreover, the flexible and durable nature of the sacks  12  also allows for convenient transport with a lower likelihood of damage as compared with conventional rigid roof planters. 
         [0033]    Hence, the sack  12  may be transported, along with the growth media  16  and the vegetation  18  and the protective pad  20 , to a desired job site. There, the sack  12  may be filled with the growth media  16  before or after placement of the sack  12  on the roof surface  11 . Similarly, the slits  14  may be formed or cut into the sack  12  before or after placement of the sack  12  on the roof surface  11 . In fact, the slits  14  can even be formed in the sack  12  during manufacture of the sack  12  or prior to transport. It then follows that the vegetation  18  may be placed in the growth media  16  prior to placement on the roof surface  11  or after the sack is placed on the roof surface  11 , so long as the sack  12  has first been filled with the growth media  16 , and the slits  14  have been formed or cut into the sack  12 . 
         [0034]    As can be appreciated, all these variations and options in formation and placement of the sack planter  10  on a roof surface  11  provide a great degree of flexibility to the installer or user. In addition, the sack planter  10  can be manufactured in nearly limitless variations of size, shape and material configuration. Hence, the shape, size and weight of the planter  10  can readily be altered either at the manufacturing facility or even at the job site to accommodate specific needs or even aesthetic or artistic expression on any given installation. 
         [0035]    Further exhibiting the unique adaptive characteristics of the fabric planter  10 , due to its pliant nature and the large contact area of relatively high friction materials, the sack planter  10  is remarkably stable when properly positioned on the roof surface  11 . Yet, the roof planter  10  can readily be removed from its resting location to allow, for example, the repositioning of the planter  10 , inspection or repair of the planter  10 , or inspection or maintenance of the surface of the roof  11 . In addition, due to their compliant and formable nature, multiple sacks  12  of the fabric planter can be positioned next to one another with minimal precision, and yet accomplish proper installation and placement. As a result, the positioning of multiple sacks  12  on the surface of a roof  11  can be accomplished in less time and with less difficulty than is required for the positioning of conventional roof planters. These benefits are in addition to the benefits of the fabric roof planter over conventional roof planters realized due to the ease with which the fabric roof planter can be transported. 
         [0036]    As a further feature of the present disclosure, the roof planter  10  may be placed upon a suitable roof surface  11 , where the roof surface  11  is covered at least in part by a surface membrane M of roofing material having a known surface composition. ( FIG. 1 ). Again, the roof surface  11  may be of virtually any profile, including for example, flat, pitched, curved or otherwise uneven. The pad  20  can be constructed from walk pad material specifically chosen to be compatible with the roofing material M upon which the particular roof planter  10  will rest. Generally, a specific roofing material manufacturer will identify specific walk pad materials that can be used upon that manufacturer&#39;s roofing material without voiding the manufacturer&#39;s warranty. Such walk pads have properties that result in an acceptable level of chemical and physical wear to the manufacturer&#39;s roofing material. Typically, each roofing material manufacturer will offer walk pads for use on its own roofing products. In this embodiment, it is preferable that the pad  20  be constructed of a material that is certified, or at least recognized or otherwise approved, by specific roofing material manufacturers to be compatible with specific roofing materials. 
         [0037]    For example, should the roof planter  10  be slated for placement atop a roof having Firestone Building Products (“Firestone’) roofing material, then the pad  20  for that specific application would be constructed of walk pad material produced by Firestone, or in the alternative, the pad  20  could be constructed of any other material specifically approved for such use by Firestone. Alternately, the pad  20  may be compatible if they are constructed of a material that imparts minimal chemical degradation or physical wear to the roofing material, even if the pad  20  is not recognized or certified by any roofing material manufacturer. Of course, it is also possible that in certain applications, the sack  12  itself may be compatible with the roof surface membrane M, so that no pad  20  is necessary for such applications. 
         [0038]    Additional variations on the basic construction are also available. For example, the exact shape and size of the roof planter  10  can be varied to form larger or smaller roof planter configurations. The sack  12  may be thick or thin. The sack  12  of the roof planter  10  may be constructed of a variety of materials, including but not limited to fabric, woven knitted high density polyethylene, rubber, paper, plastic, foam and cloth, or any other suitable material that is moisture permeable while being capable of retaining the growth media  16 . Each dimension of the roof planter  10 , and thereby all of its components, may be of varying sizes. 
         [0039]    Similarly, more than one pad  20  may be used for each sack  12 , or more than one sack  12  may be placed on a single pad  20 . The exact number of pads  20  used in each embodiment may vary. For instance, in some applications it may only be desirable to use a single pad  20 , while in other applications, a larger number of pads  20  may be desirable. In still other applications, it may be desirable to place more than one sack  12  on a single pad  20 , or to bridge one or more sacks  12  across one or more pads  20 . Further, the pad  20  may be formed of a single layer of material, or may be formed of two or more such layers. Hence, the number of pads  20  used may vary from a single pad to as many as the user may deem appropriate for the specific application. Further, the pads  20  may be attached to either the roof surface  11  or to the sack  12 , and this attachment may be accomplished by a number of methods, including for example, the use of adhesives, rivets, bolts, slides, hinges, and nails, as well as other methods that would be readily apparent to one of ordinary skill in the art. Alternately, the pad  20  may be attached to the sack  12  and the sack  12 , with the attached pad  20 , can then be set upon the roof surface  11 . The pad  20  may also be formed in a variety of shapes, such as oval, round, hexagonal or polygonal. The pad  20  may be of uniform or non-uniform dimensions, including thickness. The pad  20  may be perforated, and may comprise surface features such as abrasions, pits, and extrusions. 
         [0040]    Of course, one of ordinary skill in the art will recognize that structural members may be added to strategic positions on or in the roof planter  10  to allow the use of a variety of materials. In addition, drain holes may be added to the sack  12  or the pad  20  to regulate the moisture content of the roof planter  10 . Such drain holes may be covered with mesh or other covering to help prevent the release of the growth medium  16  from the roof planter  10 . 
         [0041]    The number and configuration of the slits  14  can also be varied. Virtually any reasonable number of slits  14  may be formed or cut into the sack  12 , so long as the vegetation  18  can be planted through the slits  14  and the slits  14  are not so numerous or positioned so that they materially degrade the functional integrity of the sack  12  nor the ability of the sack  12  to retain the growth media  16 . In addition, the slits  14  may be formed in virtually any shape and size, such that the slits  14  may actually be openings and not slit-shaped at all, again so long as the vegetation  18  can be planted through the slits  14  (or openings) and the configurations do not materially degrade the functional integrity of the sack  12  nor the ability of the sack  12  to retain the growth media  16 . 
         [0042]    Further, the vegetation  18  may consist of virtually any plant or combination of different plants that may be selected by the user. 
         [0043]    The detailed description above illustrates the invention by way of example and not by way of limitation. This description clearly enables one skilled in the art to make and use the invention, and describes several embodiments, adaptations, variations, alternatives and uses of the invention, including what I presently believe is the best mode of carrying out the invention. As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.