PANEL CONSTRUCTIONS

The present invention relates to improvements in structures including an internal frame and an outer skin made up of layers of plastics material film web.

International Patent Application No. PCT/AU2004/001841 discloses panel constructions made up into various products including box or container, side or end retainer panels, floats for preventing or minimizing evaporation from bodies of water such as ponds, dams and the like, and solar stills. In general the earlier patent specification discloses the use of an internal perimeter frame structure that is wrapped with a plurality of layers of a plastics material film web with each layer at least partially adhering to at least one adjacent layer. In smaller size panel constructions, these earlier disclosed panel constructions work well, however, in larger size panel structures, and particularly those where cushioning effect of the panel is not so important, it has been found that long lengths of side edges of the inner perimeter frame can bow inwardly under pressure of the wrapped plastics film, and moreover the panel itself can warp or twist under pressure of the wrapped plastics film web. It is therefore desirable to provide a panel construction of this type that is generally more dimensionally stable and can be made in larger sizes when required.

The objective therefore of the present invention is to provide a novel and useful panel construction of the aforementioned type that is dimensionally stable, less costly to produce and able to be made in larger sizes when required. Possible preferred usages of such panel constructions include the making of boxes or containers, evaporation minimization panels adapted to float on bodies of water such as lakes, dams, reservoirs and the like, and as insulation panels or similar in building constructions.

Accordingly, the present invention provides a panel construction having an internal frame means formed by a plurality of frame members, each said frame member having at least one outer end region defining a corner region of said panel construction, each said frame member having a portion extending inwardly from a perimeter line defined by said corner regions, said panel construction having a first perimeter band made by a flexible elongate member wound with applied pressure about said corner regions, and an outer skin formed by at least one plastics material film web wound about said internal frame means and said

first perimeter band whereby adjacent layers of the plastics material film web or webs is / are at least partially adhered to one another. Conveniently the perimeter line is generally polygonal.

The polygonal shape might be square, rectangular, pentagonal, hexagonal, or octagonal as generally described hereafter. The portions of the frame members extending inwardly may engage with at least one other said frame member or, alternatively the portions of said frame members extending inwardly cooperate with an inwardly located structural member.

Preferably at least some of said substantially rigid frame members extend between opposed corners of the polygonal perimeter line. Conveniently all said substantially rigid frame members meet at a single central zone of the polygonal perimeter line.

In one preferred embodiment the polygonal perimeter line is rectangular or square and said substantially rigid frame members form an X or cross configuration within the polygonal perimeter line.

Preferably the flexible elongate member intended to form the first perimeter band includes a plastics material film web, tape or string, or in an alternative, cable, cord, rope or wire, depending upon the application. Conveniently the flexible elongate member includes or is comprised of a plastics material film web or tape that has been pre-stretched to beyond its yield point and allowed to at least partially relax prior to being applied to the internal frame means. Conveniently the web or tape material retains some memory so that it will constrict on the frame means after being applied. Preferably the web or tape material is polyolefin such as a linear low density polyethylene material that includes some self adhesive qualities whereby several layers of the web or tape material will adhere to one another when applied to the perimeter of the frame means. In the alternative adhesive spray might be applied to the plastics material film web or tape as it is applied. In yet another alternative, at least outermost layers of the plastics material film web or webs may be heat sealed together. Conveniently the substantially rigid frame members are located substantially within a single plane. Preferably the internal frame means includes at least one member positioned within the polygonal perimeter line and extending laterally away from the single plane. The one said member may be centrally

located to define a conical or pyramid shape in said outer skin on one side of the panel construction. Conveniently two such members may be provided centrally located and extending laterally in opposite directions to define a conical or pyramid shape in said outer skin on opposed faces of the panel construction. Conveniently the or each of the aforesaid members may be made from or include a floatation material including a solid plastics material foam including but not restricted to polystyrene foam, polyurethane foam or similar.

Preferably the outer skin is made from plastics material film web wound onto the frame means and having a width greater than the length of a side edge of the polygonal frame means to fully enclose the region within the first perimeter band. In the alternative, multiple overlapping film webs might be wound onto the polygonal frame means, or a single or multiple film webs might be spirally wound onto the polygonal frame means again with their side edges overlapping. Conveniently the direction of lay of the film webs will be different. For example in the case of a rectangular or square polygonal frame means, the film webs may be wound in mutually perpendicular directions. In yet another possible embodiment, particularly where the panel construction is used as a float panel for minimizing evaporation from a body of water, the width of the film web (or webs in total) is less than the length of a side edge (Ze between adjacent corners) of the polygonal frame means whereby gaps in the outer skin appear adjacent the corners of the polygonal frame means. These gaps allow water to flow into the space within the outer skin to act as a ballast preventing the panels from blowing off the water surface on which they are positioned. In the alternative the outer skin may fully enclose the inner frame and one or more openings may be provided in a perimeter edge region of the panel construction permitting water to flow into or out of an interior region of the panel construction. The structure, however, may need sufficient floatation aids to ensure that it does remain floating. In particularly preferred arrangements the film material is a polyolefin such as a linear low density polyethylene that has been stretched beyond its yield strength and allowed to at least partially relax to retain some memory. Conveniently the film material includes some self-adherent capabilities or in the alternative adhesive is sprayed between adjacent layers. In one optional arrangement the outer skin may include at least one inner or innermost layer of black or darkly opaque film

web. The outer skin might also include a covering layer or layers of a lighter coloured film (eg light green or similar). The black or darkly opaque film prevents or substantially minimizes passage of light to the water covered by the device (when used as a float) to thereby prevent algae growth in the water. The polygonal frame means in the square or rectangular form having a cross or X-shaped internal frame means, saves 30% in internal frame materials when compared with a perimeter frame structure of the same size. Moreover, the cost and difficulty of securing side frame members at the corners of the panel construction is avoided. The frame structure can be held temporarily in the desired configuration until the perimeter film web is wound thereon thereby holding the structure in a stable and desired formation. As most of the cost of such panel constructions is in the internal frame materials and structure, considerable cost savings can be achieved while gaining a dimensionally more stable product. While the side edges will tend to bow inwardly somewhat, particularly on larger panels, the same also occurs with most perimeter frames. This, in many commercial applications does not have any significant practical effect. Such cost savings might also be achieved utilizing a generally hexagonal shaped panel construction as described hereafter. Such a construction also reduces the distance between corner zones and thereby the distance that the first perimeter band might bow inwardly.

To minimize bowing between the corners when it is preferable to do so, a panel construction may be produced as described in the foregoing and thereafter a second perimeter band may be wound with applied pressure about the corner regions outwardly of said outer skin. Once the second perimeter band is positioned, a further outer skin can be positioned formed by at least one plastics material web wound about said second perimeter band whereby adjacent layers of the plastics material film web or webs is / are at least partially adhered to one another. This process might be repeated any number of times to achieve a particular desired performance level. When the panel construction is intended to act as a cover on a body of water whether substantially still or flowing (eg, a dam, reservoir or water flow channel), the panel constructions are laid next to one another substantially

covering the water surface, are tied to adjacent panel constructions and are further tied or anchored to a bank or edge region of the body of water.

In accordance with one preferred arrangement, a panel construction is provided as described above wherein the frame members are transversely deformed along their length to provide a greater thickness of the panel construction at or adjacent a central region relative to a perimeter region of the panel construction.

Preferred features and aspects of this invention may be as defined in claims 2 to 20 inclusive as annexed hereto, the subject matter of these claims being included in the present disclosure by this reference thereto.

Several preferred embodiments will hereafter be described with reference to the annexed drawings showing steps in the production of a float panel for minimizing evaporation from bodies of water such as dams and reservoirs or a float panel so constructed. Alternatively, the drawings also illustrate the panel construction used as an insulation panel. While the present invention is particularly adapted for use in these applications, it should be understood that many of the applications shown in International Patent Application No.

PCT/AU2004/001841 including the manufacture of boxes and containers might also be used with panels constructed according to the present invention. In the annexed drawings,

Fig 1 is a perspective view of an internal frame structure for use in a panel construction;

Fig 2 shows in perspective the frame structure of Fig 1 being wound about its perimeter with a plastics material film web; Fig 3 is a section view along line III-III of Fig 2;

Fig 4 shows in plan view the internal frame means produced as shown in Fig 2 having an outer skin of flexible plastics material film web wound thereon;

Figs 4a and 4b show possible modifications of the outer tip regions of the frame legs; Fig 5 is a side view of the float panel after its outer skin has been applied;

Fig 5a is a side view like Fig 5 but showing a possible alternative embodiment;

Fig 6 is a perspective view of a further preferred embodiment in the process of manufacture;

Fig 7 is a plan view of the embodiment of Fig 6 at a further stage in its manufacture; Fig 8 is a plan view of another preferred embodiment;

Fig 8a shows a further possible modification of the outer tip region of the frame legs;

Fig 9 is a section view along line IX-IX of Fig 8;

Fig 10 is an elevational view of several modified panel constructions used in a building application;

Fig 11 is a cross-section view along line XI-XI of Fig 10;

Fig 12 is a front face elevational view of a further preferred embodiment capable of use in a building application;

Fig 13 is an edge elevation view of the embodiment shown in Fig 12; Figs 14 and 15 are partial cross-sectional views of possible different embodiments constructed in accordance with Figs 12, 13;

Fig 16 is a side elevation view of a further preferred embodiment of a frame structure according to the present invention;

Fig 17 is a side elevation view of a panel structure utilizing a frame structure as shown in Fig 16; and

Fig 18 is a perspective view of a panel construction partly made as shown in Fig 17.

Referring to the drawings, Fig 1 shows a frame structure 10, with a pair of cross legs 11 , 12 engaging with each other and secured together at a central location 13 such that four radial arms 14, 15, 16 and 17 extend outwardly from the centre location 13. The outer ends of the arms 14 to 17 form comers 18, 19,

20, 21 of a square perimeter line 22. The legs 11 , 12 are shown as a rectangular cross-sectional member made conveniently from wood, rigid plastics or metal.

While the drawings show the legs 11 , 12 are rectangular, any cross-sectional shape suitable for the material used and the application of the panel construction could be used. For example, hollow section rectangular, square or circular tubing might be used which might be filled with any suitable floatation material such as

polystyrene foam, polyethylene foam, polyurethane foam or any other similar material.

Fig 2 shows the frame structure 10 having a plastics material film web 23 from a roll of such material 24 being wound about the corners 18 to 21 , the web 23 having a width slightly greater than the width of the legs 11 , 12 of the structure 10 such that a portion 25, 26 of the web 23 extend upwardly and downwardly (as shown in Fig 3) from the top and bottom surfaces of the legs 11 , 12. The web is conveniently a polyolefin such as a linear low density polyethylene that has been stretched beyond its yield point and relaxed to retain memory. The film web may be applied with sufficient pressure to fix the frame structure in the desired configuration once it is released from a manufacturing jig or the like. The frame structure 10 might be rotated as shown in Fig 2 by arrows 27 about an axis 29 with the roll 24 being held in one position, or in the alternative the roll 24 might be arranged to orbit along path 28 about the frame 10 as the web 23 is applied to the frame 10. Sufficient layers of the film web 23 are applied adhered to one another to provide sufficient strength for winding the outer skin web material there around as described below.

Figs 4/5 illustrate a float panel construction 41 with an internal frame 10 and further including a laterally projecting member 30, 31 secured centrally to cross legs 11 , 12. The members 30, 31 may be made from a floatation material such as a plastics foam material (polystyrene, polyethylene, polyurethane foam or similar). One member 30 or 31 might be omitted providing a flat faced surface in one side of the panel, or they both could be omitted thereby providing opposed flat surfaces, depending on the end use of the panel construction. In the illustration of Fig 4, the outer skin 32 is created by a pair of overlapping webs 33, 34 dispensed from rolls of suitable plastics material film web 35, 36, and by a pair of overlapping webs 37, 38 dispensed from rolls of suitable plastics material film web 39, 40, such that the webs 33 / 34 and 37 / 38 are perpendicular to each other. It will of course be appreciated that instead of each pair of overlapping webs, a single web of sufficient width to span the desired distance between opposed side edges of the panel construction, could be used. In an alternative, the width of the web (or multiple webs together), need not fully span the width of the panel construction such that small uncovered areas at each

corner permit access to within the skin formed by the layers of the plastics material film web. By this configuration, when such a construction is used as an evaporation minimizer on a dam or similar body of water, a small amount of water can enter the internal area to provide a stabilizing weight or ballast for the construction that will prevent the float construction being unintentionally shifted by wind action. In addition to the arrangement illustrated in Fig 4, three or more rolls of overlapping shorter web width material could also be used. Alternatively spirally winding a web of shorter web width in overlapping manner could also be used for one or both of the pairs of webs 33 / 34 and 37 / 38 if desired. Again sufficient layers are built up for the required strength and durability of the panel construction 41.

When a box or container is to be produced from the panel construction, the frame 10 is desirably constructed as thin as possible as shown in Fig 4a. In this case, the frame legs 11 , 12 may include a recess 110 formed in their outer ends positioned generally in the plane of the frame 10. In this arrangement, the perimeter wrapped film might be formed into a string or rope 111 and positioned around the frame located in the corner recesses 110. Any other means of locating or holding the perimeter wrapped string or rope formed film at the outer corners of the frame 10 could also be utilized. Of course other materials could be used for the elongated string or rope, however, these materials are likely to be more expensive. Thereafter, the outer skin 32 might be positioned over the frame 10 and the perimeter wrapped string or rope as with other embodiments. In some cases a fitting or similar formation might be positioned at the outer ends of the frame legs 11 , 12 with a recess 112 formed therein generally perpendicular to the plane of the frame 10 (see Fig 4b). In this arrangement, the perimeter wrapped film 23 is located by and protected within the corner recesses 112. This arrangement might be used when a thicker panel construction is desired for a particular application.

It will of course be appreciated that when applying the film forming the outer skin 32, there is a tendency for the sides of the panel construction, that is the lengths between corners, to bow inwardly under pressure applied by the outer skin 32. If this bowing effect is to be minimized, further perimeter wrapped film (or equivalent) can be wrapped around a partly formed panel construction that has

had a first outer skin layer or layers applied, with a second outer skin layer or layers being applied around this further perimeter wrapped film (or equivalent). The process could be repeated any number of times to produce a substantially straight edge line between corners of the panel construction. Fig 5a illustrates a possible embodiment that might be used instead of the arrangement shown in Fig 5a. In this embodiment the outer ends of the legs 11 , 12 of the frame 10 have cap members 92 fitted thereto, each having an L shaped plate 93 forming a corner of the panel construction 94. The L shaped plates 93 have a length dimension substantially greater than the width of the frame members or legs 11 , 12. A perimeter band of plastic material film web 95 is wound about the corner cap members 92, the film web 95 having a width equal to or greater than the length of the L shaped plates 93. An inner structural part formed by members 30, 31 is also provided but in this case the combined length of the members 30, 31 is significantly less than the length of the L shaped plates 93 so that the rim of the panel construction 94 is substantially thicker than the central region of same. The outer skin 32 may be constructed as previously described but because of the structure as first described a well or deep depression 96 can be formed on at least one face and possibly both faces as illustrated in Fig 5a. The layers of the plastics material film web or webs forming the outer skin 32 will need to be retained in the illustrated position by some form of fastening or securing means. One possible arrangement might be to position lightweight plates on either side of the panel construction outwardly of the outer skin 32 and tie same together by through ties of any suitable type passing through the outer skin 32. In this embodiment rain falling into the float panel construction 94 would flow to the centre of the panel construction 94 and pass through suitably positioned drainage holes formed in the outer skin 32. Any of the features described for other possible embodiments disclosed herein can, where appropriate, also be used with the embodiment of Fig 5a.

Figs 6 and 7 illustrate a possible further preferred embodiment where each pair of cross-legs 11 , 12 are made up of two members comprised of lengths of tubular material 50, 51 , with retaining end caps 52 at each end. The end caps 52 may include a plug section that enters the hollow ends of the members 50, 51 and retains same parallel to and adjacent one another at opposed ends. The

tubular material is preferably lightweight but relatively rigid and could be of plastics material or thin walled metal including galvanized iron tubing or aluminium tubing. The cross-sectional shape of the tubular material could be circular, square or rectangular. In the embodiment illustrated, the members 50, 51 are bowed in the middle to provide a space 53 for a float material such as a polystyrene, polyethylene or polyurethane (or similar) block. In Figs 6 and 7 the tubular members of one leg 11 are disposed at 90° to the pair of members of the other leg 12 and fit between same. In an alternative the orientation of the leg 11 might be vertical as with the leg 12 with both members 51 , 50 either inwardly or outwardly of the members 51 , 50 of the leg 11. In a still further possible embodiment one only of the members 51 or 50 of the leg 11 might pass between the members 51 , 50 of the leg 12.

Once the legs 11 , 12 of Figs 6, 7 are configured as desired, the central regions of same are held to one another which could include being held temporarily in a manufacturing jig, or being bound together by suitable tape or other material. Mechanical fasteners could also be used. While the legs 11 , 12 are at least temporarily held in the cross configuration, a plastics material web 54 (as with earlier embodiments) is dispensed from a roll 55 of such web material around the four corners of the frame structure 10. This fixes the frame structure 10 in the selected configuration. Thereafter plastics material webs 56, 57 from rolls 58, 59 (Figure 7) are wound about the frame structure 10 and may fully enclose same, or may leave open regions 60 adjacent the corners. The structure thus formed includes a peripheral edge region 61 generally in a plane and central regions that extend laterally in both directions. Figs 8 and 9 illustrate yet another possible embodiment adapted for use as a float member 70 positionable on a water body (pond, dam, reservoir or the like) to minimize water evaporation therefrom. The float member includes a central tubular body 71 with diametrally opposed holes formed in its wall to allow three elongate frame members 72, 73 and 74 to pass there through at spaced axial locations, the outer ends of the members 72, 73, 74 forming the corners of a hexagon. A fastener 88 might secure the members 72, 73, 74 together or the members might be secured to the body 71. A pair of floatation block members 75 and 76 close the upper and lower ends of the central tubular body 71. As a

possible alternative a liquid and settable floatation material might be injected into the space above, below and in between the members 72, 73 and 74 within the central tubular body 71. The floatation material might be a polystyrene, polyethylene, polyurethane foam material or any other similar material. As a possible alternative to the structure shown in Figs 8 and 9, the central tubular body 71 might be constructed with radially extending sockets extending from its outer surface, each being adapted to receive an end of a frame member that would extend radially outwardly such that when creating a hexagonal outer perimeter shape, six separate such radially extending frame members would be provided. The inner ends of these frame members might extend through openings in the wall of the central tubular body 71 into the interior of the body 71 , or alternatively, they might abut an outer surface of the body 71. In either case fastener means might be provided to connect the radial frame members to the sockets into which they fit or otherwise to the central tubular body 71. Of course it will be recognized that in such an embodiment, the radially extending frame members might be all located in the same axial plane and moreover, it is possible (subject to space) to have any number of such frame members.

The outer ends of the frame members 72, 73, 74 (or the alternative frame members discussed in the preceding paragraph) may fit into a central opening of a tubular member 86 positioned generally cross-wise to the frame member concerned. If desired, the end of each frame member 72, 73, 74 might include a cap with a central dimple or lug 87 fitting into a corresponding aperture in the outer wall of the member 75. Alternatively one or more screw fasteners (or similar) 87 might be driven through the outer wall of the member 86 into the end face of the frame members 72, 73, 74. As illustrated the members 86 might be straight but in a possible alternative the members might be bent about the central opening such that the end regions of each tubular member 86 form an inner obtuse angle with each other. As shown in Fig 8a, the members 86 might also be generally perpendicular to the plane of the frame 10 to provide a thicker perimeter edge. Conveniently, in each case each of the end regions of the members 86 might be filled with a suitable floatation material as described in the preceding.

As with previous embodiments a first, relatively narrow plastics material film web 77 is wound circumferentially about the outer ends of the frame

members including the tubular members 75 (when provided) to form a perimeter band of such plastics material film web 77. Multiple layers of this film web 77 may be provided and the type of film web might be similar to that described in earlier embodiments. After this first film web 77 is positioned, optionally, floatation members 78 of any desired shape or material (including those described above) might be positioned generally mid way between the members 75 and a second narrow plastics material film web 79 or wound circumferentially the outer ends of the frame members to capture and hold the floatation members 78 between the two webs 77 and 79. Clearly two or more floatation members 78 might be provided between each of the tubular members 75. If desired, the or each floatation member 78 positioned between the corners of the frame 10 may be formed with a depth equal to or greater than that of the corner members 86. This minimizes any sagging of the outer skin in these regions and may direct rainwater collecting on the raft to a centre drain hole in the raft, or in the case of a raised centre raft, to the lowest point that is above the moulded end sections on the diagonal legs.

Thereafter a first plastics material film web 80 having width to more than span the distance between two adjacent members 75 is wound bodily about the float member 70 as illustrated whereby at least part of the edge zones of the web 80 engage over an end region of a member 75. This process is repeated by winding a second and third plastics material film webs 81 , 82 again over the float member 70 such that at least most of the upper and lower surfaces of the float member 70 are covered by multiple layers of the plastics material film webs. Again the film webs may be as described in relation to earlier embodiments. The film webs 80, 81 , 82 form the outer skin 83 and may overlap at the corner members 86 or, as illustrated, may leave a small gap 84. It is intended, in use that the float member 70 fill partially with water such that substantially only one face (upper or lower) is above the water surface. Conveniently a number of drainage holes 85 might be provided in one or both the upper and lower surfaces to allow rain water falling on the surface to drain through same if the water pools on the surface. Floatation of the float member 70 is achieved by providing sufficient floatation members or means as described to allow one surface of the

member 70 to remain above the surface of the water body on which it is positioned.

In one preferred embodiment rafts may be produced where the outer skin fully encloses the frame 10 and thereafter drainage holes might be formed in the outer skin. Conveniently holes might be formed in the perimeter edge of the raft (ie through the perimeter wrapped film) on the intended water line to allow a significant amount of water to fill the centre cavity to act as ballast in use. It is also proposed to heat weld or similarly adhere edge zones of the outer skin to prevent delamination of the outer skin. Figs 10, 11 illustrate panel constructions generally made in accordance with previously described embodiments used in a building application where the panel construction substantially fills the space between wall studs, ceiling / roof beams or rafter members, and floor joists or similar. In this case, each panel construction 41 includes an internal frame 10 formed by crossed legs 11 , 12 with a perimeter band of plastics material film web 23 wound around the outer ends of the legs 11 , 12. An outer skin 32 of flexible plastic material film web or webs is or are wound about the frame 10 and perimeter band 23 to generally enclose same, however, in this case a flexible flap region 89 is formed along at least one edge of the panel construction. As shown in Fig 11 , the flap regions 89 in the illustrated embodiment extend from opposite longitudinal sides of the panel construction and from opposite main faces of the outer skin. The flap regions could of course extend from only one of the main faces of the outer skin and in a similar manner could also be provided along the end edges. The flap regions 89 are made from the same plastics material film web or webs as is the outer skin 32. As shown in Fig 11 , the flap regions 89 are intended to overly the studs or similar wall / ceiling / roof members 90 and may be secured thereto by nailing, gluing or similar fastener means. If desired, the spaces within the panel construction could be filled with an insulating material.

Figs 12 to 15 illustrate further preferred embodiments for a panel construction 105 usable in applications similar to Figs 10 and 11 described above. In Figs 12 to 15, the internal frame structure 10 is formed by a pair of wires or wire rod members 97, 98 that cross one another in the middle and are welded, soldered or otherwise secured together at the cross over point. The

wires or wire rod members can be relatively lightweight so long as they have sufficient strength in compression to resist constricting forces applied by the plastics material film webs. The outer ends of the members 97, 98 are bent at 90° to form a section 99 of short length defining the width of the panel structure eventually formed. The length of section 99 can be varied to vary the width of the panel structure formed. The outer ends of the sections 99 may also be bent to form tab members 100 for reasons described hereafter. Of course the tab members 100 may be omitted if desired. To construct this panel configuration, the members 97, 98 are formed, welded at their cross over central locations and held in a jig. A plastics material film web is wound about the sections 99 to form the perimeter band 101. Thereafter, the outer skin 102 is formed by winding a plurality of layers of plastics material film web about the frame structure 10 and the perimeter band 101. A plurality of these layers may be wound sufficiently loosely to create air pockets 103 between layers to provide an insulating effect. If desired some of the webs applied to form the outer skin might be stretched locally in spaced zones to assist with formation of the aforesaid air pockets 103. Such an arrangement is shown in Fig 14. If it is necessary to increase the insulating effect, an insulating material 104 might be provided to fill the space within the outer skin 102 as shown in Fig 15. The width of the panel construction, /e the distance between the sections 99 of the frame members is such to substantially fill the space between a buildings studs, joists, rafters or the like. As the panel construction has a degree of compressibility between its side edges (because of the nature of the frame 10), the width can be chosen to be just greater than the space into which it is to fit so that an interference fit is created. If tab members 100 are provided, they may engage the building frame member (stud, joist, rafter or the like) to hold the panel construction in position prior to applying cladding material to at least one side of same. This arrangement is particularly useful for providing insulation beneath flooring which has generally not been previously possible. Figs 16 to 18 illustrate yet another possible preferred embodiment according to the present invention. In this embodiment, a frame structure 10 is formed of flexible frame members 120 having outer end regions 121 bent to form a portion around which a perimeter band 23 of plastics material film web (or

similar) can be wound. The frame members 120 could be made of tubular material including metal or rigid plastics, metal wire or rod material or wood. All that is needed is that it should be relatively incompressible in a longitudinal direction but capable of bending in a transverse direction. The outer end regions 121 might be formed by fittings secured to the end of the members 120 or might be physically bent, as illustrated, from the length of the members 120. Conveniently the frame members 120 are joined at their intersecting mid points 123. The end regions shown in Fig 16 may be splayed outwardly.

When producing a panel construction utilizing a frame structure 10 as shown in Figs 16 to 18, the individual members 120 are conveniently bent to form a dome or similar such that the end regions 121 are generally disposed vertically and are parallel to each other. In this condition, the frame structure 10 may be held in a jig (not shown) and the perimeter band 23 might be wrapped around the end regions 121. Subsequently and as with other disclosed embodiments an outer skin 124 might be created from plastics material film web wrapped about the frame structure 10. In the illustration of Figs 16 to 18, the frame members 120 are elastically deformed into the domed shape illustrated but it is equally possible to plastically or permanently deform the members 120 into a desired structural shape. The drawings show a panel construction having a hexagonal outer perimeter but other outer shapes could be created including but not limited to square, rectangular, and octagonal. Of course, also as described with regard to earlier embodiments float members might be attached to the frame structure 10 at any desired location including at each of the corners defined by the frame end regions 121. The construction described and shown in Figs 16 to 18 has the advantage of creating a domed structure with a domed upper surface 125 simply and without additional members when the panel construction is intended to float on a body of water such as ponds, dams or reservoirs. The panel construction so formed might also conveniently be used as a small domed cover or protector for plants growing in a particular ground area by simply cutting the lower region 126 of the outer stem 124 from the construction formed as described above.

As with a previously described embodiment, it is possible to also wrap a second perimeter band about the corners and provide a further outer skin wrap about this second perimeter band.

It will of course be appreciated that the preferred embodiments described and illustrated herein are exemplary in nature and variations or modifications therein can be made within the scope of the annexed claims. Moreover features described with reference to one embodiment might, if appropriate be used in relation to any other embodiment described herein.