Synthetic boards for exterior water-resistant applications

Abstract

Specially configured synthetic boards are provided for use with conventional carpentry tools and techniques to form flat, water-tight surfaces such as decks, roofs, walls, boat decks, hulls, and the like. The boards are formed to their desired shape and scale by extruding mixtures of wood particles and thermoplastic materials through appropriate converging dies. In one configuration, the edges of the boards have complementary configured outwardly facing recesses that permit them to be joined to form the watertight surfaces, and in another configuration the boards have features that interact with separate plastic structures to provide water tightness.

Description

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of priority from U.S. Provisional Patent Application Ser. No. 60/593,505 filed on Jan. 20, 2005, the entire contents of which are incorporated herein by reference.

FIELD OF THE INVENTION

This invention generally relates to construction materials and, more particularly, to specially configured synthetic boards for providing water-tight exterior surfaces such as for decks, roofs, siding, and boat applications.

BACKGROUND OF THE INVENTION

In the construction of outdoor surfaces, such as decks and porches, it is common to use flat materials that are weather-resistant. Typically, these are pressure-treated wood, cedar or teak planks, mahogany planks and, more recently, synthetic boards which are extruded wood/plastic composites.

In normal construction, boards of the above types are spaced apart to provide gaps, allowing moisture to drain through the crack fromed between the butt joint as from a deck to the area below. Problems arise when it is required that the area below be more or less protected from rain and snow as, e.g., when a patio is placed below an elevated deck.

Solutions for this problem are available on the market today, but all have certain limitations. Interlocking aluminum planks (e.g., U.S. Pat. No. 5,816,010) are effective in providing leak-resistant lower levels. Various underlayments, covered with rubber or plastic sheet goods, are generally available. These are also effective.

However, there are two drawbacks with the above. First is appearance; many prefer the look of a traditional wooden floor. A second is related to construction techniques in that the above-cited existing systems require non-standard carpentry, e.g., pre-drilling and sawing of aluminum extrusions and cementing of large areas of sheet goods.

Consequently, one primary object of the present invention is to provide construction materials in the form of leak-resistant boards which are both attractive, i.e., wood-like in appearance and that are amenable to being worked with ordinary carpentry tools, techniques, and fasteners.

An additional object of the invention is to provide a low-cost and environmentally friendly means for producing wood-composite materials with the desired leak-resistant properties since the use of various products such as pure wood or plywood is presently expensive and accelerates forest depletion.

Materials that come in various compositions of wood particles and plastic have been available for many years. Their advantages over natural wood include greater durability and resistance to weathering. They are also often less expensive to manufacture than traditional wood or aluminum products and have the benefit of being producible from recycled plastic and wood products. In addition to these manufacturing benefits, wood-plastic composites have the same workability as wood with respect to the use of traditional carpentry tools and fasteners, and conventional methods for their fabrication have been well established.

One method of generating wood-plastic materials is by heating mixtures of the composites and applying an extrusion process whereby the melted mixture is forcibly passed through a converging die assembly with the desired cross-sectional shape. For example, U.S. Pat. Nos. 5,746,958 and 5,851,469 describe methods for mixing and stabilizing such material and extruding the heated composite through a die to provide board-shaped products of desired dimensions. Such a process could be adapted for shaping materials with novel dimensions and features (i.e., channels) meant for creating leak-resistant characteristics.

A further object of the invention is therefore to produce wood-like and leak-resistant material with an inexpensive and environmentally-friendly fabrication process.

Other objects of the invention will, in part, be obvious and will, in part, appear hereinafter when the detailed description is read with reference to the drawings.

SUMMARY OF THE INVENTION

The invention relates to channeled, interlocking boards with integral elastomeric or supplemental seals that are effective in constructing extensive, leak-resistant lateral surface, as for a deck, roof, wall or boat application.

In material content, the boards are typical of the composites now used for decking: 50% more or less of wood fibers, the remainder, of thermoplastic binders, typically high and low density polyethylenes. Alternatively, more or less plastic can be used.

Such boards are wood-like in appearance, extremely rugged and inexpensive. The low cost derives from the fact that the wood content comes from waste sawdust, and the plastic is from recycled goods, such as bags and bottles. Inexpensive processes for producing boards of such material can be adapted for incorporating the desired leak-resistant characteristics.

BRIEF DESCRIPTION OF THE DRAWINGS

The structure, operation and methodology of the invention, together with other objects and advantages thereof, may best be understood by reading the detailed description in connection with the drawings in which each part has an assigned label or numeral that identifies it wherever it appears in the various drawings and wherein:

FIG. 1 is a diagrammatic perspective view of a completed deck structure assembled with boards according to the invention;

FIG. 2 is a diagrammatic perspective view of a single basic board according to the invention;

FIG. 2A is an enlarged cross-sectional view of part of a channel of the board of FIG. 2;

FIG. 3 is a diagrammatic, partially exploded, view of a pair of basic boards, showing the interlocking features;

FIG. 4 is a diagrammatic perspective view of a beginning and finishing board according to the invention;

FIG. 4A is an elevation of the board of FIG. 4;

FIG. 5 is an elevational view of an assembly of basic boards, including beginning and finishing boards according to the invention;

FIG. 5A shows an alternative means for sealing a beginning board against a vertical wall;

FIG. 6 is a diagrammatic view of boards with an alternative geometry for outwardly facing channels in accordance with the snap-fit features of the invention;

FIG. 6A is an enlarged diagrammatic view of the channels of FIG. 6;

FIG. 7 is a diagrammatic, partially exploded view of boards with an alternative geometry, along with separate channel sheets in accordance with the invention;

FIG. 8A is an elevational view of the boards and channel sheets of FIG. 7;

FIG. 8B is a blown-up elevation view of the joint and channel section of the boards of FIG. 7;

FIG. 9 is a diagrammatic, partially exploded view of the boards of FIG. 7 with an alternative design for laterally extending channel sheets;

FIG. 10 is a diagrammatic perspective view of the boards of FIG. 7 joined lengthwise along the channel sheets of FIG. 9;

FIG. 11A is an elevational view, partially exploded, of the boards of FIG. 9 fastened and sealed to underlying surfaces;

FIG. 11B is an enlarged elevation view of joint and channel section of the boards of FIG. 11A;

FIG. 11C is an elevational view of the boards of FIG. 9 with alternative means for fastening to an adjoining vertical surface;

FIG. 12 is a diagrammatic cross-sectional elevation of an alternate embodiment of the invention provided with an enlarged fastening surface; and

FIG. 13 is a diagrammatic cross-sectional elevation of an alternate embodiment of another embodiment of the invention having yet another enlarged fastening surface.

DETAILED DESCRIPTION

This invention relates to the production and use of materials suitable to provide extensive generally planar surfaces, such as a deck roof, or wall, which are water-tight to the areas enclosed, thus allowing such areas to be useful as protected areas, e.g., a patio, second deck, porch, storage, or living space. Additionally, the materials appropriately sized may be used in boat applications such as for hulls, decking, interior finishes, and topside structures.

Referring to FIG. 1, a diagrammatic perspective view of a completed deck structure 50 is shown assembled with boards 52 according to the invention. Boards 52 are sealed from moisture and are otherwise configured to channel water out and away from sheltered area 54.

Reference is now made to FIG. 2, which shows an embodiment of a board 100. Board 100 is shown with opposite outward facing channels 106, provided with elastomeric strips 102, which are applied in channels 106 and which seal against moisture when compressed by opposing tongues 104. Such strips are preferably co-extruded with the body of boards 100 in a manner to be described, or may be added in a secondary operation. The boards 100 can alternatively be covered entirely with elastomeric material. Note that the durometer of the elastomeric strips 102 is low, typically Shore 40A, to avoid undue stress in the board structure as the strips are compressed. Note also, that for clarity, the boards are shown dramatically foreshortened; Width “W” is typically several inches, Length “L” is typically several feet or more and can be made in standard lengths as needed. The elastomeric strips may be from the group of materials consisting of silicon, RTV, caulking compound, rubber, latex, and any of these in the form of an O-ring

Reference is now made to FIG. 2A, which is a magnified view of the elastomeric strip 102, shown as a thin meniscus, typically of polyurethane. Circular cross-section seals (O-ring style) laid into extruded channels are more appropriate in secondary fabrication operations.

Reference is now made to FIG. 3, which is a perspective view of two basic boards 100, slightly separated from their assembled positions. Here, it can be seen that on every joint formed by mating the complimentary shaped channels 106, there are two side-by-side seals 102, providing improved water tightness.

Reference is now made to FIGS. 4 and 4A, which are, respectively, perspective and elevational views of a needed additional board configuration 200, to be used at the beginning and finishing boundaries of the extensive spans of basic boards 100. One side presents a rounded nose feature, seen at 208. The other side, to mate with basic boards 100, features identical channels 206, upwardly extending tongues 204 and elastomeric strips 202. The use of beginning and finishing boards 200 is best shown in FIG. 5.

Reference is now made to FIG. 5, which is an elevation of a typical construction. (Only two basic boards 100 are shown for clarity. There would typically be many more in the main span.) A beginning board 200, on the left of the drawing, is shown to be in proximity with a vertical member 310. Such a member is, for example, siding on a structure or a riser on a stair, on which the subject boards are to form the tread.

The joint between board 200 and vertical member 310 is sealed with a bead of caulk 302 or alternatively suitable flashing can be used. The finishing board 200, on the right side of the drawing, finishes the run of boards 100 in a neat and workmanlike manner.

Still referring to FIG. 5, the boards 100 and 200 are fastened to joists 312 with standard decking screws 308 without pre-drilling. However, in certain applications, the use of predrilling may be desired and special screws provided with self-sealants may be used. Screws 308 are typically stainless steel, galvanized or ceramic coated for corrosion resistance. As mentioned, they may also be of the self-sealing variety.

Reference is now made to FIG. 5A, which shows, in elevation, the use of a metal flashing strip 306, lead or aluminum, as an alternative to caulk 302. This is appropriate to lap siding, such as clapboards or shingles.

Reference is now made to FIGS. 6 and 6A, which are both diagrammatic elevational views showing an alternatitive snap-fit joint configuration for assembling boards 300 in accordance with the invention. Here, tongues 320 of each channel 330 are configured and arranged to provide both camming action and flexibility so that, as the channels 330 are slid toward one another to form a joint, the camming action causes them to flex about their root sections. This bending causes their ends to enter a relief area 350 (FIG. 6A) formed in each channel 330. Upon being pushed together further, the flexed tongues snap back to complete the joint. The snap-fit mechanism together with hidden nails 310 secure the boards to the attachment surface. The base of channels 330 provide sufficient surface area for nails 310 so that the surface areas of the subject boards are flush at interlocked joints. Elastomeric strips 202, shown as thin menisci, seal against moisture when compressed by opposing tongues 320.

Reference is now made to FIG. 7, which is a diagrammatic perspective and partially exploded view of an alternative embodiment of the invention, combining boards 402 with channel strips 404. Tongues 408 of channel strips 404 fit into complimentary configured grooves 406. Water flows between boards 402 and into channels 404 which are angled to direct water away from a sheltered area such as 102 (shown in FIG. 1).

Reference is now made to FIG. 8A, which shows, in elevation, the boards 402 of FIG. 7 fastened to a joist 504 with standard decking screws 502, without pre-drilling. FIG. 8B shows an enlarged elevational view of boards 402 engaged with channel strip 404. If desired, the spacing between the upwardly depending tongues may be dimensioned to provide a tight butt joint between adjacent boards to reduce the amount of moisture that can reach the channels 404.

Reference is now made to FIG. 9 which shows a diagrammatic perspective view of an alternative embodiment for a multi-channel sheet 606. Channel sheet 606 is extruded to include multiple channels 602 and 604, and the like, which may be repeated to sensible lengths. FIG. 10 shows a diagrammatic perspective view of the boards of FIG. 7 joined lengthwise for extensive spans along channel sheets 606 of FIG. 9. Water that may flow into a joint 702 is drained outward along channel sheet 606.

Reference is now made to FIG. 11A where the boards 402 and 802 are fastened to a joist 806 with standard decking screws 502, with or without pre-drilling. Channel sheet 606 spans across the bottom side of boards 802 and 402.

The finishing boards 802, on the left and right side of the drawing, finish the run of boards 402 in a neat and workmanlike manner. The joint between board 802 and vertical member 808 is sealed with a bead of caulk 810.

Screws 502 are typically stainless steel, galvanized or ceramic coated for corrosion resistance and may be self-sealing.

Reference is now made to FIG. 11B, which shows an enlarged elevational view of a board 402 with channel sheet 606. Here, the channel defined between adjacent board edges can be more clearly seen.

Reference is now made to FIG. 11C, which shows, in elevation, the use of a metal flashing strip 804, lead or aluminum, as an alternative to caulk 810. This is appropriate for lap siding, such as clapboards or shingles.

FIG. 12 shows in diagrammatic cross section an elevational view of boards 700 having an alternate channel configuration shown generally at 702 that is provided with a flat elongated surface area 704 to promote ease in fastening operations. A screw fastener, or the like, may be inserted to underlying attachment structure along the centerline to form a robust joint.

FIG. 13 shows a diagrammatic cross section yet another elevatioinal view of boards 800 having an alternate channel configuration shown generally at 802 that is provided with a slightly angled elongated surface area 804 to promote ease in fastening operations. Elastomeric seals may be provided in either of the channels of FIGS. 12 and 13 as previously described and may if sensible be extended over the overlapping fastening flat areas to provide even more robust sealing joints.

It is important to note that this construction system is completely compatible with the customary carpentry of balusters, railings, skirts and the like.

The inventive boards can be produced using wood-composite materials, having the advantage of being inexpensive while retaining wood-like workability and appearance. One embodiment of production includes a means for generating an easily transportable composite mixture of wood particles and thermoplastic materials (i.e., post-consumer recycled plastics), as illustrated in U.S. Pat. No. 5,746,958. Such material is shaped with the desired features (e.g., the channels shown in 206 and rounded edges 208) by passing it under pressure, in a partially or fully melted state, through a converging die shaped accordingly. This process is similar to and may be adapted from an embodiment of U.S. Pat. No. 6,527,532. The extrusion process may also incorporate a means for laminating the elastomeric layer 202, alternatively covering the entire board. The layer 202 can alternatively be applied separately from the extrusion process.

Such boards may be used to promote water resistant deck surfaces, roofs, siding, boat decking, and boat hulls. The dimensions of the boards can be appropriately sized in thickness, width, and length, according to the particular application.

Based on the various described embodiments and teachings of the invention, other variants of it will occur to those skilled in the art and it is intended that such variants be within the scope of the invention as claimed.

Claims

1. A substantially planar surface comprising corresponding and interconnected water proof pieces that form water resistant channels between them for directing liquid away from the surface, said water proof pieces having opposed surfaces and edges with at least one lengthwise recess formed in a surface thereof adjacent one edge, said recess facing outwardly from said surface and configured and arranged to engage corresponding complementary shaped recesses in other like water proof pieces to provide surfaces with liquid channeling, leak resistant joints formed between adjoining water proof pieces.

2. A board for use with other like boards to construct surfaces, said board having opposed surfaces and edges with at least one lengthwise recess formed in a surface thereof adjacent one edge, said recess facing outwardly from said surface and configured and arranged to engage corresponding complementary shaped recesses in other like boards to provide surfaces with liquid channeling, leak resistant joints formed between adjoining boards.

3. The board of claim 2 wherein the cross-sectional shape of said recess comprises one concave section and one convex section arranged aside of one another.

4. The board of claim 3 wherein said concave section resides further inboard of said edge than does said convex section and is larger than said convex section.

5. The board of claim 4 wherein at least a portion of said concave section includes lengthwise sealing means to further assure that a leak resistant joint is formed between adjoining boards.

6. The board of claim 5 wherein said sealing means comprises a lengthwise meniscus of flexible sealing material.

7. The board of claim 6 wherein said flexible sealing material is selected from the group of materials consisting of elastomers, silicon, RTV, caulking compound, rubber, latex, and O-ring.

8. The board of claim 5 wherein said sealing means comprises a lengthwise groove formed in the bottom of said concave section and filled with a sealing material that sits proud of said surface of said concave section.

9. The board of claim 2 wherein said recess further includes a section for engaging adjoining boards along at least one common edge.

10. The board of claim 5 wherein said recess is configured and arranged as a snap fit joint, said joint having a widened and substantially planar surface at the base of said recess so that fasteners may attach said board to a surface beneath said board through said widened and substantially planar surface.

11. The board of claim 10 wherein said recess further comprises:

a fastener at the base of said recess sufficiently small so that said board and said complimentary board are flush and so that said fastener is hidden from the top surface of said board; and

a lengthwise seal adjacent said hidden fastener to further assure that a leak resistant joint is formed between adjoining boards.

12. The board of claim 2, wherein said board is comprised of composite materials selected from the group consisting of wood particles and plastic so that the appearance of said board is wood-like, said board being pliabile for use with common carpentry tools and fasteners and strengthened strength for common construction purposes selected from the group comprising decks, roofing, siding, boat decks, and boat hulls.

13. The board of claim 12 wherein said plastic is comprised of polyethylene.

14. The board of claim 13 wherein said board is formed by extrusion.

15. The board of claim 14 having additional structural features formed during extrusion including wire and rod stiffeners.

16. The board of claim 5 wherein said sealing means is co-extruded or contemporaneously applied.

17. A method for producing a wood-plastic composite for a board having opposed surfaces and edges with at least one lengthwise recess formed in a surface thereof adjacent one edge with the recess facing outwardly from the surface and configured and arranged to engage corresponding complementary shaped recesses in other like boards to provide surfaces with leak resistant joints formed between adjoining boards, said method comprising the steps of:

a) providing particles of wood component;

b) providing a thermoplastic component;

c) proportioning the wood component and thermoplastic components in a mixing ratio from about 65/35 to about 40/60;

d) heating the mixture; and,

e) extruding the mixture through a die shaped according to the board's desired dimensions and profile.

18. The method of claim 17, further including the step of co-extruding an elastomeric strip along said grooves.

19. The method of claim 17, further including the step of laminating said board with a PVC layer.

20. A leak-resistant planar surface which channels water away from an underlying area comprising:

a plurality of boards aligned adjacent to one another with two lengthwise grooves along the downward face of each board;

channel strips placed underneath the lengthwise boundaries between said boards wherein said strips comprise protruding tongues that insert in a complimentary manner into said grooves of said boards so that said channel strips form channels for directing liquid away from said surface.

21. The leak-resistant planar surface of claim 20 wherein said channel strips are formed as an integrated sheet of periodically repeating such channel strips with flat areas spanning and underneath them.