Deck Board

Abstract

This invention relates to a deck board and more particularly, to a reduced material deck board. In accordance with this invention there is provided a deck board 5 comprising an operatively upper board section having at least one operatively downwardly depending support leg terminating in at least one flange, an underside of the flange having a concave surface. 19 20 24 21 94 44 06 S ep 2 02 4 0 6 S e p 2 0 2 4 2 0 2 4 2 1 9 4 4 4

Description

FIELD OF THE INVENTION This invention relates to a deck board and more particularly, to a reduced material 5 deck board. BACKGROUND TO THE INVENTION Hollow deck boards or reduced material deck boards are well-known and widely used. These deck boards are lighter and cheaper to manufacture, as a result of using less io material. A disadvantage of hollow deck boards having square or round bores are that they may become waterlogged. The water thus collected inside the deck board damages the material due to water absorption and cause rot or damage to the deck board. 15 Particularly a reduction in the useful life of the deck board. Some deck boards do not have bores therein but have open, reduced material sections. 20 NewTechWood alleges the following on their website at http: / / www.newtechwood.com: “Hollow vs. Solid core composite deck boards 2024219444   06 Sep 2024 What are the Pros and Cons with hollow composite deck boards vs. solid core composite deck boards? 5 Most composite deck board manufacturers in the US offer only solid core boards. The main reason is due to the speed and ease in manufacturing those boards vs. hollow boards. It is much easier and faster to extrude solid composite boards than it is hollow. Most manufacturers don’t want to deal with the difficulty or expend the extra time to manufacture hollow boards. io So why does NewTechWood offer a hollow board? NewTechWood is one of the only companies in the US that offers a hollow board, and we do so for a couple of reasons. Offering a hollow board cuts down the weight of 16’ board by as much as 32% or 10 pounds when compared to a solid board. This makes 15 them easier to work with and if you’re retrofitting an older deck where the structure is sound and you just want to replace the surface boards, the hollow boards create less stress on that older substructure than do solid boards. What’s the difference in the strength of the hollow boards compared to the solid 20 boards? Many people think that because the board is hollow it must be significantly weaker than a solid board. The fact is the arch structure of the voids in NewTechWood’s hollow board makes up for the use of less material in the core. The industry standard for maximum span as set by the International Code Council for the US is 16” on 25 center. That means each joist in the substructure must measure 16” from the center 2024219444   06 Sep 2024 of one joist to the center of the adjacent joist. Most installation guides for manufacturers of solid boards require a span of 16” on center or less. The hollow boards offered by NewTechWood are also rated by the ICC at 16” on center. That means NewTechWood’s UltraShield hollow boards will hold your hot tub just the same 5 as the solid boards. NewTechWood also offers solid core boards as well. Those are recommended for stairs and other installations where you don’t want the grooves for hidden fasteners to show, or if you’re not installing a fascia board, and we also recommend them for commercial installations. io What’s the difference is price? This is perhaps the most attractive reason for using NewTechWood UltraShield hollow boards over solid. Because the board is hollow, less material is used in the manufacturing process. This enables NewTechWood to pass the savings along to the consumer. The cost savings can be huge, as much as 22%. 15 For example, if you build a 12’ x 16’ deck, you save $363.00 on the cost of materials. That’s a significant amount for you to spend on other priorities for your home. ” United States patent application number US 20030154662 A1, entitled “Hollow profile 20 decking system comprising plank and anchor using anchor flange construction” in the name of Andersen Corporation, discloses: A decking system, decking components and an installed deck for use on a support structure. The decking system comprises hollow profile planking units having anchor flanges on opposite edges that cooperate with an anchor structure to form a deck or 25 platform. The flanges and the anchor units are shaped and configured to closely 2024219444   06 Sep 2024 interact and form an installed platform structure. The planks comprise an extruded thermoplastic wood fiber composite having an internal structure sufficient to withstand installation, engineering forces placed on the installed platform, weathering and use. The anchor structures have a shape that conforms to the anchor flanges on the 5 decking profiles to hold the deck in place. This patent application includes the following drawing showing a cross-section of the hollow profile planking unit. It is clear that water can get trapped in openings or bores 46. 10 South African provisional patent application number 2016 / 05995 in the name of Eva-Last Distributors (Pty) Ltd discloses a reduced material deck board having an arched underside. The arches are cut into the deck board, which would otherwise be solid, 15 thus reducing the amount of material used. This provisional patent application is included herein, its entirety, by way of reference. 2024219444   06 Sep 2024 OBJECT OF THE INVENTION It is an object of this invention to provide a deck board which will, at least partially, alleviate the above-mentioned difficulty. 5 SUMMARY OF INVENTION In accordance with this invention there is provided a deck board comprising an operatively upper board section having at least one operatively downwardly depending support leg terminating in at least one flange, an underside of the flange having a concave surface. io There is provided for an underside of the upper board section to have a concave surface. A yet further feature of the invention provides for two flanges to extend transversely 15 away from opposite sides of a lower end of the leg. There is also provided for anti-slip formations to be located in or on an upper surface of the upper board section. 20 There is also provided for an upper portion of the two flanges comprising a flat or nonconcave surface, and wherein an underside surface of the upper board section links two consecutive flanges belonging to two consecutive downwardly depending support legs. 2024219444   06 Sep 2024 The anti-slip formations may be a number of parallel, elongate grooves or parallel elongate protrusions or any other convenient anti-slip formation. This invention extends to a deck board comprising an elongate body which, in cross 5 section, has a number of substantially I-beam shaped sections with operatively horizontal upper or head sections connected to each other and lower operatively horizontally extending foot sections being shorter in length than the head sections so that their free ends are spaced apart. io A central connecting section of the I-beam connects the upper and lower sections to complete the I-beam shape. An underside of the foot section is concave. 15 An underside of the connected head sections is concave. Upper surfaces of the foot sections are substantially operatively horizontal. There is provided for the deck board to be extruded. 20 There is provided for the deck board to manufactured from a composite material. There is provided for the deck board to be extruded from a filled thermoplastic polymer material. 2024219444   06 Sep 2024 There is provided for the deck board to be extruded from a wood plastic composite material. There is provided for the decking board to have a wall thickness of at least 4mm. 5 There is further provided for the deck board to be used for outdoor decking. These and other features are described in more detail below. 10 BRIEF DESCRIPTION OF THE DRAWINGS One embodiment of the invention is described below, by way of example only, and with reference to the drawings in which: Figure 1 shows an upper perspective view of a deck board in accordance with the 15                  invention; Figure 2     shows an underside perspective view of the deck board Figure 1; Figure 3     shows a plan view of the deck board of Figures 1 and 2; 20 Figure 4 shows a bottom view of the deck board of Figures 1 to 3; Figure 5 shows a left side view of the deck board of Figures 1 to 4; 2024219444   06 Sep 2024 Figure 6 shows a right-side view of the deck board of Figures 1 to 5; Figure 7 shows a front-end view of the deck board of Figures 1 to 6; and 5 Figure 8 shows a rear end view of the deck board of Figures 1 to 7. DETAILED DESCRIPTION OF THE DRAWINGS With reference to the drawings, a deck board is generally indicated by reference numeral 1. io The deck board 1 includes an elongate body that has an operatively upper board section 4 that has a number of operatively downwardly depending support legs 5 extending downwardly from an underside surface 8 of the upper board section 4. 15 Lower ends 6 of each leg terminate in a transversely extending flanged that, in effect, forms two transversely extending flanges 7 extending transversely away from opposite sides of lower ends 6 of the legs 5. In cross-sectional profile view, the legs, flanges and upper board section resemble I-20 beam sections connected side-by-side with their upper or head sections connected to each other and lower foot sections, spaced apart. An underside surface 9 of each flange 7, is concave. Underside surfaces 8 of the upper board section 4, between the downwardly depending legs 5, are also concave. 2024219444   06 Sep 2024 Upper surfaces 7a of the flanges are operatively level and, in use, receive parts of fastener clips thereon. The upper portion of the flanges 7a comprising a flat or non-concave surface. 5 An underside surface 8 of the upper board section 4 links two consecutive flanges 7 belonging to two consecutive downwardly depending support legs 5. An upper surface 2 of the upper board section 4 includes anti-slip formations in the io form of a series of parallel and elongate grooves, parallel with the main axis of the deck board 1. It will be appreciated by those skilled in the art that any other convenient anti-slip formations may be formed on the upper surface, as may be required. The deck board 1 is extruded from a wood plastic composite material. The thickness 15 of the board profile is at least 4 mm (0,15 inches) thick, but a minimum of 7 mm (0,27 inches) thickness is more suitable. At a thickness of less than 7 mm, the brittleness of the composite is so low that the product becomes unusable. In use, deck boards are placed side-by-side on joists of a substructure on which an 20 outdoor deck is to be formed. The deck boards are attached with fastener clips as is known in the art. Wings or other parts of the fastener clips locate on part of the upper surfaces 7a of flanges at opposite outer edges of the deck board. This invention thus provides a deck board comprising an elongate body which, in cross 25 section, has a number of substantially I-beam shaped sections with operatively 2024219444   06 Sep 2024 horizontal upper or head sections connected to each other and lower operatively horizontally extending foot sections being shorter in length than the head sections so that their free ends 10 are spaced apart. Space between two free ends 10 may form an opening of a channel 11. The channel 11 may be bounded by the upper board 5 section 4 at a top, the free ends 10 at a bottom, and the legs 5 at the sides. A central connecting section of the I-beam connects the upper and lower sections to complete the I-beam shape. An underside of the foot section is concave. An underside of the connected head sections is concave. Upper surfaces of the foot io sections are substantially operatively horizontal. All corners and edges of the board are rounded and the arched surfaces (8 and 9) adds to the strength of the board and ensures improved load distribution. The spaced apart flanges ensure that water will easily be drained from the board. Even if water 15 collects on the level surfaces 7a, and especially those at the opposite outer edges of the deck board, these surfaces are exposed and will dry relatively quickly. Water will thus not collect, or not collect for an undesired length of time, on or in the board, thereby enhancing its durability. The board is relatively light, as a result of using less material than a solid board. The board, however, remains strong enough and fit for 20 purpose. In the present invention the concave shape of the on the underside of the flange offers several advantages. Firstly, it is optimal for manufacturing decking boards, particularly when extruding thermoplastic or thermoplastic composite materials. Additionally, this 25 shape enhances dimensional stability post-manufacturing, helping maintain the 2024219444   06 Sep 2024 intended form and strength during exposure to weather conditions and thermal cycling, whether in storage, transit, or use. The concave design also improves functionality during installation and regular use as a deck board, while simultaneously enhancing the board's structural strength. Also, this shape aids in water runoff, preventing 5 moisture accumulation and promoting durability. In rheology the flow behaviour of molten metals and metal alloys above liquid temperature are considered Newtonian. Molten thermoplastic polymers and molten thermoplastic polymer composites are non-Newtonian fluids with viscosities that are very sensitive to shear rate, shear history, and / or temperature history. This is one of io the differences between a metal or metal alloy and a thermoplastic or thermoplastic composite material and is of particular importance in extrusion manufacturing. When manufacturing certain shapes through extrusion, the shaping die can cause parts of the extruded material to flow at different rates than others, especially when 15 the die shape is highly asymmetrical as is in the case in the present invention. The non-Newtonian flow behaviour of thermoplastics and thermoplastic composites exacerbates this relative differential flow behaviour in manufacturing. The final article formed by such an extrusion sets in place internal stresses within the extruded article along the lines of the differential flow rates. 20 This is characteristic of thermoplastic or thermoplastic composite materials arises directly from the complex interaction of long polymer chains over their shear rate, shear history, and / or temperature history at high kinetic energies associated with their molten state. Long polymer chains when excited by high kinetic energy become highly 25 mixed and tangled in this excited state and are set in place into a stressed state when 2024219444   06 Sep 2024 the kinetic energy of a molten state lowers and locks the polymer chains into a stressed state. These internal stresses will work to deform the extruded article from its original shape. 5 In the case of a symmetrical thermoplastic extrusion or thermoplastic composite extrusion, these internal stresses will generally cancel each out resulting in a dimensionally stable final article. In a highly asymmetrical thermoplastic or thermoplastic composite extrusion these unbalanced stresses will cause the extruded article to significantly deform in the direction of the nett internal stress unless resisted io by some other opposing force. These internal stresses within a thermoplastic or thermoplastic composite extrusion persist after the final product is cooled, shrinks and hardens. The stiffness, modulus of elasticity, of thermoplastic or thermoplastic composite 15 materials is relatively low. This leads to an inherent characteristic of the extruded article having low stiffness relative to the force of internal stresses within the article arising from the relatively high differentials in flow behaviour of the material. Meaning the extruded article will easily deform due to such stresses. 20 It is the case that over long term exposure to thermal cycles due to environmental conditions, the highly internally stressed initial state will relax toward a less stressed state than the initial state but the stiffness, modulus of elasticity, of a thermoplastic or thermoplastic composite material is variable over temperature within the domain of the solid state. At higher temperature the modulus of elasticity of such a material is lower 25 and therefore even more prone to deformation from internal stress. 2024219444   06 Sep 2024 The asymmetrical shape of the present invention being an example hereof. These characteristics of thermoplastic or thermoplastic composite extrusions lead to the extrusion forming into a shape different from the desired one in highly asymmetrical 5 extrusions or deforming from the desired shape after extrusion. In practice, adjustments must be made to ensure that the final product, once cooled, shrunk, and hardened, matches the desired shape. Without these adjustments, the deck board may curl, warp, cup, bow, crook or twist after exiting the shaping die or afterwards during the cooling process, or after cooling when exposed to regular thermal cycles io from environmental conditions, or in use. Some prior art documents describes the use of aluminium, a highly homogeneous, and highly isomorphic material, which generally flows in molten state according to expected Newtonian flow behaviour. Such a metal or metal alloy can be formed into a 15 mould when in liquid form, flows relatively homogeneously and forms a final article with relatively low internal stress after cooling, shrinking and hardening. And furthermore relatively very low internal stress relative to the stiffness, modulus of elasticity, of the metal or metal alloy material. It is also the case that a metal when formed into a solid, forms a highly regular crystalline solid which is not subject to highly 20 variable modulus of elasticity over change in temperature within the solid phase domain as is the case with thermoplastic and thermoplastic composite materials. One method of compensating for the unstable characteristics of highly asymmetrical extrusions in thermoplastics is to provide a die shape, such as the concave shape in 25 the present invention, which provides an internal stress in the opposite direction of 2024219444   06 Sep 2024 the nett internal stress of the cross-sectional shape generally, within a certain region of the cross-sectional shape. This compensatory technique allows for such an extrusion which maintains the desired cross sectional during manufacturing and also the desired dimensional stability over the length of a finished article, preventing the 5 finished article from curling, warping, cupping, bowing, crooking or twisting. The present invention uses thermoplastics or thermoplastic composites, which remain permanently "soft" non-crystalline amorphous solids and can be reformed if desired necessary. The prior art does not teach the use of thermoplastics due to the difficulty io in extruding the necessarily thick thermoplastic shapes, with their inherent instability instead relying on aluminium or an aluminium alloy. Thermoplastics are used in the present invention due to their good longevity and high ultimate strength, and high degree of toughness and durability, especially when 15 considering the weight of the material and the ultimate product. The concave underside of the flanges creates an obtuse angle where the upper side of the flanges meets the 'downwardly depending support leg.' This obtuse angle allows water on the upper side of the flanges to run off easily, preventing moisture from becoming trapped. Trapped moisture can lead to moisture absorption and material brittleness over long-20 term exposure and cause cracks or breaks or damage in freezing conditions when absorbed water expands at freezing point. The concave underside of the flanges also provides elasticity, allowing the flanges to better engage with a substrate supporting the deck board. This elasticity allows the 25 material at the bottom of the profile shape to strain within the materials yield strength 2024219444   06 Sep 2024 and ultimate strength against an imposed downward load, but in a different direction to the strain in the rest of the profile shape when typically used between supports providing for increased profile stiffness and ultimate strength under loading conditions. 5 It will be appreciated by those skilled in the art that many other embodiments are possible without departing from the scope of the invention. For example, the board can be manufactured from any material suitable for extrusion. The board may also be used for outdoor decking, indoor floors or covering wall surfaces. io It is envisaged that the invention herein described is convenient to use in that the decking board does not include any cavities or grooves in which water will be trapped. This makes the board suitable to use for outdoor decking. Furthermore, the profile of the deck board increases load bearing capabilities of the board. The concavity of the underside of the upper head sections of the board optimises material usage with 15 respect to product performance beyond what is typical of hollow core extruded deck boards and prevents the possibility that water becomes trapped on or in the deck board. Where the top element gets thicker, near to the downward leg, it reduces peak strain within the profile. 20

Claims

1. A deck board comprising an operatively upper board section having at least one operatively downwardly depending support leg terminating in two flanges that extend transversely away from opposite sides of a lower end of the leg, an underside5 of the two flanges comprising a concave surface.

2. The deck board of claim 1, wherein an underside of the upper board section comprises a concave surface.

3. The deck board of claim 1, wherein anti-slip formations are located in or on anio upper surface of the upper board section.

4. The deck board of claim 3, wherein the anti-slip formations comprise parallel, elongate grooves or parallel elongate protrusions.15   5. The deck board of claim 1, wherein the deck board is manufactured from acomposite material.

6. The deck board of claim 5, wherein the composite material is a filled thermoplastic polymer material.

207. The deck board of claim 5, wherein the composite material is a wood plasticcomposite material.

8. The deck board of claim 7, wherein the deck board is extruded from the wood25 plastic composite material.2024219444   06 Sep 20249.    The deck board of claim 1, wherein the deck board is an outdoor deck board.

10. The deck board of claim 1, wherein the deck board has a wall thickness of at5 least 4mm.

11. The deck board of claim 1, wherein an upper portion of the two flanges comprising a flat or non-concave surface,.io 12. The deck board of claim 1, wherein an underside surface of the upper board section links two consecutive flanges belonging to two consecutive downwardly depending support legs.

13. A deck board comprising an elongate body which, in cross section, comprises 15 a number of substantially I-beam shaped sections with operatively horizontal upper or head sections connected to one another and lower operatively horizontally extending foot sections being shorter in length than the head sections so that free ends of the foot sections are spaced apart, wherein the underside of the foot section is concave, the deck board being manufactured from a composite material.2014. The deck board of claim 13, wherein a central connecting section of the I-beam connects the upper and lower sections to complete the I-beam shape.

15. The deck board of claim 13, wherein an underside of the connected head25 sections is concave.2024219444   06 Sep 202416. The deck board of claim 13, wherein upper surfaces of the foot sections are substantially operatively horizontal.5   17. The deck board of claim 13, wherein the composite material is a filledthermoplastic polymer material.

18. The deck board of claim 13, wherein the composite material is a wood plastic composite material.io 19. The deck board of claim 13, wherein the deck board is extruded from a wood plastic composite material.

20. The deck board of claim 13, wherein the deck board is an outdoor deck board.15   21.   The deck board of claim 13, wherein the deck board has a wall thickness of atleast 4mm.

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