Patent Application
20190338526
The invention relates to a roof paver system and, more specifically, to a roof paver system having an aerodynamically stable ballast block.
Single-ply protected-membrane roof systems are generally known and are especially suitable for low-sloped roofs and decks. These systems typically include a single-ply water-impermeable membrane, with or without thermal insulation layers, held in place and protected from the elements by ballast systems of various designs. These systems may also include loose-laid, well-rounded stones such as river gravel, standard paving blocks, composite tongue-and-groove board, and lightweight interlocking ballast blocks. In general, conventional ballast systems are often used in areas where exposure to high wind conditions may be anticipated because they are capable of withstanding greater wind velocities than conventional built-up roofing systems.
Conventional ballast blocks are usually extruded or precast concrete of flat rectangular shape laid over a roof membrane in a contiguous grid pattern. However, even this construction does not assure dislodgement of the ballast blocks under certain weather conditions. High velocity winds, such as those of hurricane-force, passing over irregular or critical roof locations may induce an aerodynamic pressure differential across the conventional blocks to lift them out of place. Instead of simply making ballast blocks heavier and the roof supports stronger, various designs have evolved for resisting the lifting force, such as the aforementioned lightweight ballast blocks secured to each other by interlocking edges.
However, despite these design efforts, the net upward aerodynamic loading acting on the ballast blocks may lift them and present dangers to people and/or structures in the vicinity, as well as expose the underlying roof membrane and substructure to damage.
One such example that attempts to address these issues is an interlocking ballast block roofing system disclosed in U.S. Pat. No. 5,377,468. The '468 patent discloses a labyrinthine system of channels extending from a top side to a plurality of chambers positioned along a bottom side thereof. Additionally, the labyrinthine system of channels permits fluids to pass between adjacent blocks without direct exposure of underlying roofing materials to the elements.
While disclosed design solves some of the above problems, the known labyrinthine system of channels is aerodynamically problematic, as it includes a plurality of 90° turns within the channels that frictionally lower the efficiency of fluid flow from the top side to the chambers on the bottom side. Additionally, the complexity of the system of channels decreases the robustness of the manufacturing and installation process, by increasing the probability of damaging the system of channels.
Consequently, there is a need for an interlocking ballast block roofing system that improves upon conventional designs through more efficient fluid flow, such as water and air, and, while being robust during the manufacturing and installation process.
A ballast block is provided with a body and a plurality of fluid receiving channels. The body includes a top surface, a bottom surface positioned opposite the top surface, and a first side extending between the top surface and the bottom surface. The plurality of fluid receiving channels are disposed along the first side in a plurality of units and extending from the top surface to the bottom surface to form a zigzag pattern. Each unit of the plurality of units having an adjacent pair of fluid receiving channels extending at opposing angles toward each other from the top surface to the bottom surface in an approximate V-shape.
The invention will now be described by way of example, with reference to the accompanying Figures, of which:
Now with reference to the Figures, an exemplary embodiment of the invention will be described.
With respect to
Now with respect to
In an exemplary embodiment of the invention, the ballast block 1 includes a body 10, a plurality of legs 20, a plurality of fluid receiving chambers 30, and a plurality of fluid receiving channels 40.
Now with respect to
The first side 13 is substantially perpendicular to the top surface 11 and the bottom surface 12 and extends widthwise there between. A major surface of the first side 13 is substantially planar. The second side 14 extends substantially perpendicular to the top surface 11 and the bottom surface 12 and extends widthwise there between. The second side 14 is positioned opposite the first side 13 and approximately parallel to the planar major surface of the first side 13. In the shown embodiment, the second side 14 has a length approximately equal to the length of the first side 13, and a surface of the second side 13 is substantially planar.
The third side 15 extends substantially perpendicular to the top surface 11 and the bottom surface 12, and extends widthwise there between. The third side 15 also extends substantially perpendicular to the first side 13 and the second side 14, and extends lengthwise there between.
The fourth side 16 extends substantially perpendicular to the top surface 11 and the bottom surface 12, and extends widthwise there between. The fourth side 16 also extends substantially perpendicular to the first side 13 and the second side 14, and extends lengthwise there between. Additionally, the fourth side 16 is opposite the third side 15 and approximately parallel to the third side 15. The fourth side 16 has a length approximately equal to the length of the third side 13.
Now with reference to
As shown, the plurality of legs 20 are positioned along the bottom surface 12 and extend away from the body 10. Each leg 20 provides space between the bottom surface 12 and an underlying support surface (described in detail below). In the shown embodiment, each leg 20 is generally rectangular and extends along the bottom surface 12, from first side 13 to the second side 14. The plurality of legs 20 are positioned substantially parallel to each other in the shown embodiment. A first facing end 21 of each leg 20 is beveled, sloping away from first side 13, towards the second side 14. In the shown embodiment, the first facing end 21 extends to the surface of the first side 13. In another embodiment, it is possible that the first facing end 21 is spaced a distance from the surface of the first side 13, such that a portion of the bottom surface 12 is positioned between the surface of the first side 13 and the first facing end 21.
A second facing end 22 of each leg 20 extends to the second side 14, such that the second facing end 22 is flush with the surface of the second side 14, in approximately the same plane.
Each leg 20 includes a first longitudinal sidewall 23a and an opposite second longitudinal sidewall 23b extending lengthwise on each side of the leg 20. The width of the first and second longitudinal sidewalls 23a, 23b is approximately equal, and determines the distance each leg 20 extends from the surface of the body 10. In the shown embodiment, the first longitudinal sidewall 23a and the second longitudinal sidewall 23b are beveled, extending at an angle from the bottom surface 12, towards each other. However, one skilled in the art should appreciate that in another embodiment, the first longitudinal sidewall 23a and the second longitudinal sidewall 23b may extend approximately perpendicular to the bottom surface 12, parallel to each other, with a 90 degree angle of intersection provided by the leg 20 and bottom surface 12. Also, in other embodiments, each legs
Now with reference to
As shown, the plurality of fluid receiving chambers 30 are positioned between the legs 20 and defined by the first and second longitudinal sidewalls 23a, 24b of the legs 20 and the bottom surface 12. As shown, each fluid receiving chamber 30 extends along the length of legs 20, from the first side 13 to the second side 14. Each fluid receiving chamber 30 is open on both the first side 13 and the second side 14.
Now with reference to
As shown, the pluralities of fluid receiving channels 40 are disposed along the first side 13 of the body 10. Adjacent pairs of channels 40 are positioned in units 17, and form a zigzag pattern in the shown embodiment. That is, each unit 17 includes a pair of adjacent channels 40 extending at opposing angles toward each other from the top surface 11 to the bottom surface 12 in an approximate V-shape. The zigzag pattern extends along the length of the first side 13. In the shown embodiment, the first side 13 includes 3, 4, 5, or more units 17 of adjacent pairs of channels 40. A distance between the pair of adjacent channels 40 of the unit 17 along the top surface 11 is greater than a distance between the pair of channels 40 along the bottom surface 12. Each channel 40 has a first width on a top surface end 41 that tapers down along the length of the channel 40 to a smaller second width on a bottom surface end 42.
An upper flat portion 80 and a beveled lower portion 81 are provided between each pair of adjacent channels 40 of the unit 17, above described V-shape. The upper flat portion 80 extends between the top surface ends 41 of the adjacent channels 40, and generally includes flat surface along a plane of the first side 13. The beveled lower portion 81 extends from an approximate mid-point along the length of the pair of adjacent channels 40 of the unit 17, inward, towards the bottom surface end 42 of the channels 40 of the unit 17.
As shown in
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Now with reference to
As shown, the roof paver system 100 in an exemplary embodiment uses ballast blocks 1 according to the invention arranged in a pattern. As shown in
In the shown embodiment, the underlying support surface may include a water-impermeable membrane, M, such as single-ply PVC sheet, insulation I, and a water-proofing layer W. However, other conventional multi-component underlying support surface systems are contemplated for use with the roof paver system 100, depending on design requirements, such as conditions of use, building codes, and the like. In shown embodiment, the legs 20 of the ballast blocks 1 rest on the roof membrane M, where the membrane M further defines a fourth side of the fluid receiving chambers 30.
The ballast blocks 1 are positioned in adjacent rows and interlock at their complementary tongue 50 and groove 60 on the third and fourth side 16, respectively, of two ballast blocks 1 in the adjacent row. Hence, the laid ballast blocks 1 interact with one another to resist usual lifting forces.
With adjacent ballast blocks 1 supported on the membrane M, the flat second side 14 of one adjacent ballast block 1 abuts the first side 13 of an adjacent ballast block 1. Water drainage and airflow pathways formed across the surface of the first side 13 by the combination of the fluid receiving channels 40 with the fluid receiving chambers 30 between the bottom surface 12 of the body 10 and the membrane M, are shown by arrows A in
In the shown embodiment of
The interlocking ballast blocks 1 according to the invention that cooperate with each other to provide an aerodynamically-stable roof paver system 100 suitable for unusual wind conditions. By arranging ballast blocks 1 in a row such that they interlock with ballast blocks 1 in adjacent rows, air and water readily flow between the ballast block 1 edges, the pressure in the fluid receiving chambers 30 is quickly equalized in response to a sudden reduction in air pressure above the ballast blocks 1. The tendency of the ballast blocks 1 to be displaced is therefore reduced.
Additionally, the ballast blocks 1 are lightweight, inexpensive to manufacture, and relatively easy to install or replace if they become damaged.
While embodiments of the ballast block and roof paver system have been described in detail, various modifications, alterations, and changes may be made without departing from the spirit and scope of the ballast block deck and roof paver system according to the present invention as defined in the appended claims.
