US20060283140A1

US20060283140A1 - Wooden decks

Info

Publication number: US20060283140A1
Application number: US11/144,374
Authority: US
Inventors: Stephen Kennedy
Original assignee: Intelligent Engineering Bahamas Ltd
Current assignee: Intelligent Engineering Bahamas Ltd
Priority date: 2005-06-03
Filing date: 2005-06-03
Publication date: 2006-12-21

Abstract

A wooden deck is formed by a structural sandwich plate member with a wooden layer applied to one surface.

Description

FIELD

The present invention relates to wooden decks and floors such as may be used in ships, yachts, foot bridges, balconies, pool sides, piers, marinas and other vessels and structures.

BACKGROUND

Wooden decks are used in many locations to provide a comfortable and attractive surface for people to walk upon, for example on the decks of cruise ships and other pleasure boats and in public and private buildings such as hotels on balconies, walkways, poolsides, etc. Conventionally, a wooden deck is laid by covering the base surface, e.g. concrete or steel, with a layer of plywood on which is laid the decking, e.g. teak planks. The plywood layer provides a degree of cushioning to the deck, making it more comfortable to walk on and also providing a degree of sound absorption.
Through use, the wooden deck will experience wear and may also suffer due to exposure to the elements. Accordingly the deck and plywood layer will eventually need replacement. In many cases, the underlying base may have deteriorated due to water penetration or internal stresses and may no longer be sufficiently flat. Accordingly, before the replacement plywood layer and decking can be laid, a self-leveling screed must be applied. This is time consuming and known self-leveling screeds do not provide an appropriate backing for the deck.

SUMMARY

There is therefore a need for an improved manner of constructing a wooden deck or floor.
According to the present invention, there is provided a deck member comprising:
a structural sandwich plate member comprising first and second plates and a core of plastics or polymer material bonded to said first and second plates with sufficient strength to transfer shear forces therebetween; and
a layer of wood attached to an outer face of said first plate.
The present invention also provides a method of manufacturing a deck member comprising:
forming a structural sandwich plate member comprising first and second plates and a core bonded to said first and second plates with sufficient strength to transfer shear forces therebetween; and
fixing a wooden layer to said first plate.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be described below with reference to exemplary embodiments and the accompanying schematic drawings, in which:
FIG. 1 is a cross-sectional view of a wooden deck member according to a first embodiment of the present invention;
FIG. 2 is a perspective view of the wooden deck member of FIG. 1;
FIG. 3 is a view illustrating a method of laying a wooden deck according to a second embodiment of the present invention;
FIG. 4 depicts a vessel having a wooden deck according to an embodiment of the present invention; and
FIG. 5 depicts a building having a wooden deck according to an embodiment of the present invention.
In the various drawings, like parts are indicated by like reference numerals.
The wooden deck member 10 shown in FIG. 1 comprises a structural sandwich plate member having on one side a wooden layer 14, e.g. made of planks of a hardwood such as teak. The wooden layer may in some cases be made of artificial wood-like composites, such as fibre-boards, possibly faced by a layer of natural wood, e.g. a veneer. As shown in FIG. 2, the wooden layer may also include narrow strips 15 of a contrasting color. The wooden planks or boards 14 may also be spaced apart to facilitate drainage in applications in which wetting will be frequent. In that case, it is preferable that the top plate of the structural sandwich plate member is stainless steel or provided with a corrosion prevention treatment, such as galvanization, or layer.
The materials, dimensions and general properties of the plates of the structural sandwich plate member of the invention may be chosen as desired for the particular use to which the structural sandwich plate member is to be put and in general may be as described in U.S. Pat. No. 5,778,813 and U.S. Pat. No. 6,050,208. Steel or stainless steel is commonly used in thicknesses of 0.5 to 20 mm and aluminum may be used where light weight is desirable. Aluminum in general may be used in thicknesses 2 to 4 times that of steel, i.e. 1 to 50 mm, to give comparable strength. Similarly, the plastics or polymer core may be any suitable material, for example an elastomer such as polyurethane, as described in U.S. Pat. No. 5,778,813 and U.S. Pat. No. 6,050,208.
The structural sandwich plate member comprises upper (first) and lower (second) plates 11, 12 which may be of steel or stainless steel (e.g. of thickness in the range of from 0.5 to 20 mm) or aluminum (e.g. of thickness in the range of 1 to 50 mm). Edge plates (not shown) are welded or adhered between the plates 11, 12 around their outer peripheries to form a closed cavity. Alternatively, the structural sandwich plate member may be assembled in a mold, obviating the need for edge plates. In the cavity between the plates 11, 12 is a core 13 of plastics or polymer material, preferably compact (i.e. not a foam) and preferably a thermosetting material such as polyurethane elastomer. This core may have a thickness in the range of from 15 to 200 mm. The core 13 is bonded to the plates 11, 12 with sufficient strength and has sufficient mechanical properties to transfer shear forces expected in use between the two plates.
The required bond strength between the core 13 and plates 11, 12 will depend on the exact use the deck member is to be put. If the deck member is required to contribute significantly to strength of the structure of which it is to be a part, the bond strength should be greater than 3 MPa, preferably 6 MPa, and the modulus of elasticity of the core material should be greater than 200 MPa, preferably 250 MPa. A lower modulus may be used where high temperature conditions will not be experienced. For low load applications, where the typical use and occupancy loads are of the order of 1.4 kPa to 7.2 kPa, the bond strength may be lower, e.g. approximately 1 MPa. By virtue of the core layer, the deck member has a strength and load bearing capacity of a stiffened steel plate having a substantially greater plate thickness and significant additional stiffening. The member, of course, need not be flat but may take any shape required for its intended use.
To reduce the weight of the plate member, a plurality of lightweight forms or inserts may be provided in the core. The forms 14 may comprise blocks of foam, extruded tubes, or hollow, solid skin polypropylene balls, for example. The forms in general need not contribute to the structural strength of the member and thus need only have sufficient strength and mechanical properties to withstand pressures and temperatures that will occur during injection of the core. In low-load applications, the core material may also include a low-density and low-cost filler such as coconut husk, cardboard or string.
The manufacturing of the panel may be performed in situ, or off-site in factory conditions and the finished panel transported to the installation site. The latter allows for automation of the process and improved dimensional accuracy, as well as more reliable bonding.
A method of manufacturing a deck according to a second embodiment of the present invention is shown in FIG. 3. In this embodiment, the second plate 21 is part of a pre-existing structure, e.g. a deck of a cruise ship or liner. The deck 21 may have deformed due to internal stress or may present an uneven surface due to corrosion or wear. In this case, (re-)installation of a conventional wooden deck, comprising plywood backing layer and hardwood planks, is difficult. According to the method of the invention, the pre-existing deck is stripped back to solid metal and cleaned, then uncured core material 22 is poured into an open mold formed on the existing deck 21. A top plate 23 is lowered onto the top. The top plate 23 is provided with a large number of small, e.g. 1 mm diameter, through holes which allow the air trapped underneath the plate to escape as the core material cures and expands. The core material, before curing, need not be fluid enough to be self leveling as the weight of the top plate 23 assists this. The top plate 23 can be loaded or restrained during the curing process, if necessary to ensure it is level and not distorted by any expansion of the core material during curing.
After curing of the core material, the through-holes can be sealed, but this may not be necessary if they will be covered by the wooden layer or if the top plate 23 and core materiel are sufficiently water resistant.
Once the core material is fully cured, the top plate 23 presents a flat and level surface to which the wooden decking can be directly attached, e.g. by adhesive or by fittings provided on the top plate. One possibility is to bolt the wooden planks 24, 25 to the top plate 23 using the through-holes 26, which may be threaded for this purpose.
The core 22 provides a useful degree of sound deadening and also provides a comfortable feel to the deck. If desired, the thicknesses of the core and top-plate as well as the bond strength between the core and plates can be selected so that the resulting structural sandwich plate member has significant structural strength. The replacement wooden decking can therefore reinstate to design strength or upgrade the existing deck, allowing, in the case of vessels, removal of stiffening and/or pillars in the levels below the deck. In general, the same materials may be used for the core in the second embodiment as in the first. Also, the same forms, inserts and fillers may be employed.
The invention is also advantageous in that the structural sandwich plate member is robust and durable so that replacement of worn planks can in many cases be carried out without the need to repair or replace the structural sandwich plate member.
FIG. 5 illustrates a vessel—such as a cruise ship, ferry, pleasure craft or yacht—which incorporates a wooden deck according to an embodiment of the invention in an area, e.g. the foredeck, where passengers may walk. The deck may be installed as prefabricated panels or laid on an existing base, as described above.
FIG. 6 illustrates a building in which a deck according to the invention has been applied, e.g. on an exterior balcony. The deck may be installed as prefabricated panels or laid on an existing base, as described above. The invention may of course also be used in interior spaces.
It will be appreciated that the above description is not intended to be limiting and that other modifications and variations fall within the scope of the present invention, which is defined by the appended claims.

Claims

1. A deck member comprising:

a structural sandwich plate member comprising first and second plates and a core of plastics or polymer material bonded to said first and second plates with sufficient strength to transfer shear forces therebetween; and

a layer of wood attached to an outer face of said first plate.

2. A deck member according to claim 1 wherein said layer of wood comprises a plurality of wooden planks laid side by side.

3. A deck member according to claim 2 wherein said layer of wood includes contrasting strips.

4. A deck member according to claim 1 wherein said core comprises a low density filler.

5. A deck member according to claim 4 wherein said low density filler forms a proportion by volume of said core in the range of from 30 to 70%, preferably 40 to 60%, most preferably 45 to 55%.

6. A deck member according to claim 4 wherein said filler is selected from the group comprising coconut husk, cardboard and string.

7. A deck member according to claim 1 wherein said core comprises a compact elastomer, e.g. polyurethane.

8. A deck member according to claim 1 wherein said core comprises a plurality of lightweight forms or inserts.

9. A deck member according to claim 8 wherein said forms do not tesselate in a plane parallel to said first and second plates and have principal dimensions in the range of from 20 to 200% of the distance between said first and second layers

10. A deck member according to claim 8 wherein said lightweight forms are hollow.

11. A deck member according to any claim 8 wherein said forms are spherical.

12. A deck member according to claim 1 wherein said core has a thickness greater than or equal to 20 mm.

13. A deck member according to claim 1 wherein either or both of said first and second plates is(are) made of metal, preferably steel, stainless steel or aluminum.

14. A deck member according to claim 1 wherein said first and second plates have a thickness greater than or equal to 0.5 mm.

15. A deck member according to claim 1 wherein said second plate comprises part of an vessel or structure.

16. A deck member according to claim 1 wherein said wooden layer is adhered to said first plate.

17. A method of manufacturing a deck member comprising:

forming a structural sandwich plate member comprising first and second plates and a core bonded to said first and second plates with sufficient strength to transfer shear forces therebetween; and

fixing a wooden layer to said first plate.

18. A method according to claim 17 wherein said second plate comprises a part of a pre-existing structure.

19. A method according to claim 18 wherein said step of forming a structural sandwich plate member comprises:

applying a layer of uncured core material to said second plate;

placing said first plate on top of said uncured core material; and

allowing or causing said core material to cure.

20. A method according to claim 19 wherein said first plate has a plurality of apertures extending therethrough to allow the escape of air.

21. A method according to claim 17 wherein said core comprises a low density filler.

22. A method according to claim 21 wherein said low density filler forms a proportion by volume of said core in the range of from 30 to 70%, preferably 40 to 60%, most preferably 45 to 55%.

23. A method according to claim 21 wherein said filler is selected from the group comprising coconut husk, cardboard and string.

24. A method according to claim 17 wherein said core comprises a compact elastomer, e.g. polyurethane.

25. A vessel or structure including a deck member comprising:

a layer of wood attached to an outer face of said first plate.