WO2008051085A1

WO2008051085A1 - Extended, layered construction element

Info

Publication number: WO2008051085A1
Application number: PCT/NO2007/000367
Authority: WO
Inventors: Bjarne Nordli
Original assignee: Isolaft As
Priority date: 2006-10-19
Filing date: 2007-10-19
Publication date: 2008-05-02
Also published as: NO20064790L

Abstract

Extended, layered construction element (1) comprising an upper structure (2) having an upper, external layer (3) and a lower structure (6) comprising a lower, external layer (7), said upper and lower structure (2 and 6 resp.) being rigidly attached to one another by spacing elements (10). Near the upper, external layer (3) and near the lower, external layer (7) through openings (12) ) for receiving pretensioning elements (18) are arranged with defined intervals across the length extension of the construction element. Inside at least one of upper, external layer and lower, external layer a plate (4, 8) is arranged to take up shear stress, said plate (4, 8) covering substantially the entire layer (3 resp. 7) and is directly or indirectly attached to said layer as well as to said spacing elements (10). The invention also concerns a floor/ ceiling construction and a roof construction assembled by a number of such construction elements.

Description

Extended, layered construction element

The present invention concerns a prefabricated, layered, extended construction element for a floor/ ceiling structure as well as for a roof construction of a building construction. The invention furthermore comprises a floor/ ceiling structure and a roof construction assembled by such construction elements.

Background

Industrial buildings are today raised rationally from modules. The same has becoming increasingly relevant also for domestic buildings which will probably be based on modules which can be mass produced in factories. With respect to their construction as such little has happened in the area of domestic buildings recent years. Contemporary assembling of domestic buildings is typically not very rational and takes place at the building site with no automation. The customers, however, demand rapid occupation and do not allow raising of the houses during summer and postponing its interior decoration until winter when the weather is bad. It is thus a need for construction elements which can be assembled to a building construction in a simple and easy manner while the construction elements as such are easy and simple to produce and satisfy all relevant building regulations.

Prefabricated building constructions are as such generally known. US patent No. 3,927,498, for example, teaches a system of using prefabricated elements where the elements constitutes a framework for the building construction. JP 2001 178748 and JP 06000606 describe a prefabricated building and a floor structure.

Objective

It is an object of the present invention to provide prefabricated construction elements which readily and quickly can be assembled and used as a floor/ ceiling structure or as part of a roof constructions, said construction element and the assembled constructions thereof having properties with respect to fire safety, moment of inertia, ability to take up shear stress as well as insulating properties that are least as good as those of existing constructions in the art.

The present invention The above objects are achieved by means of a construction element according to the invention as defined by claim 1.

According to another aspect the present invention concerns a complete floor/ ceiling structure as defined by claim 25. According to yet another aspect the present invention concerns a roof construction as defined by claim 29.

Preferred embodiments of the invention are disclosed by the dependent claims. The thickness of the construction element according to the invention can vary and is chosen e.g. based on to the need for moment of inertia that is desired or required for the application in question and based on the need for insulation.

It should be emphasized that it is essential that the pretensioning elements are arranged between the lower sidewalls to increase the moment of inertia in the direction across the elements. If, as an alternative, pretensioning elements are only arranged through the vertical centre of the construction elements, the fundamentals of this effect is not obtained. Since steel has a Youngs modulus that is 20 times higher the Youngs modulus of wood (in the fibre direction), by using pretensioning elements that corresponds to 1/20 of the area of the wood in the lower structure, a structure that endures 3 times the load is obtained. This assumes, however, that the pretensioning elements are located near the lower structure.

When the construction. element according to the present invention is to be used in a roof construction and more specifically in a ridge roof construction, pairs of construction elements are hinged together longitudinally in a manner allowing them to be folded under transportation and at the building site to be unfolded to an angle that corresponds to the desired roof profile. This angle can be delimited in one of several ways and a convenient way is to shape the end surfaces of the short sides hinged together with an inclined angle chosen such that the movement of unfolding the two hinged together construction elements is restricted by said short sides landing against each other when the desired angle is reached. It can easily be decided geometrically which angle said short sides of the construction elements must have to obtain a certain roof angle. The ends of the construction elements facing away from the hinges are conveniently attached to a foundation, being it beams, e floor/ ceiling structure according to the present invention or other types of foundation. Thereby the integrity of the roof is ensured so that it can not be blown off in strong winds and at the same time it is ensured that the hinges at the ridge of the roof can not be overloaded. In applications where the roof construction is mounted on top of a floor/ ceiling structure such as the floor/ ceiling structure according to the present invention, one also obtains the advantage that increased weight on the roof in the form of snow contributes with forces directed outwards (tension) on the floor/ ceiling structure, thereby increasing its moment of inertia in the direction perpendicular to the ridge. When the construction elements according to the present invention are arranged for assembly on a building construction, they are preferably lifted up by means of a crane or the like. Thereafter the construction elements are pressed against each other with suitable tools. Close to the upper and possibly close to the lower external layer tongues and grooves are typically arranged to hold the construction elements in exact vertical position in relation to one another or a combination of preferably rounded or conical plugs and corresponding holes to hold the construction elements in an exact position in relation to one another horizontally as well as vertically. The vertical positioning and mutual fixation of adjacent construction elements is major to ensure the integrity of the complete construction over time, to eliminate the possibility of mutual parallel displacement of the construction elements and to ensure smooth, fine surfaces of floors as well as ceilings. The horizontal fixation is important to ensure the integrity and strength of the complete construction. The design with plugs and corresponding holes provides a higher degree of safety than the solution of tongue and groove, since the horizontal fixation is not dependent upon glue or friction resistance between tongue and groove, which can change over timed and with changes in temperature and humidity. Use of an adapted tool as mentioned above makes it simple to overcome the frictional forces between plugs and holes in the wall or between tongue and groove when a new construction element is assembled to another one (or more) already in place.

The invention is now to be described in further details with reference to the drawings, where Figure 1 is an expanded perspectival view of a construction element according to the invention intended for use in a floor/ ceiling structure.

Figure 2 is an expanded perspectival view of an alternative embodiment of a construction element according to the invention intended for use in a roof construction.

Figure 3 shows two construction elements of the type shown in Figure 2, hinged together for use in a roof construction.

Figure 4 shows a partly assembled floor/ ceiling structure according to the present invention.

Figure 5 shows a partly assembled roof construction according to the present invention in an embodiment where there are load-bearing gable walls at each end of the house and a ridge beam between the tops of these walls.

Figure 6 shows a partly assembled roof construction that is mounted directly on top of a ceiling which may be, but need not be, a floor/ ceiling structure according to the present invention.

Figure 7 shows a section of a roof construction which is attached to an underlying wall in a manner that is slightly different from those being illustrated by the Figures 5 and 6.

Figure 8 is an enlarged sectional view illustrating the construction element shown in Figure

1. By the term "structure" as used herein is understood a physical unit comprising at least one physical layer and more typical at least two physical layers combined in a permanent manner; the structure may also comprise further physical units which do not constitute complete layers, i.e. they do not completely overlap the at least one layer which is mandatory for that structure.

The terms "upper" and "lower" as used herein refer to their position in the drawings which also mainly corresponds to up and down when the elements are fully assembled and mounted in a building construction. The term "external" refers to what constitute an external layer of each individual element and does not imply that same element will be part of an external surface in a building construction; a floor/ ceiling structure will e.g. never be part of an external surface of a building construction. The statement that a plate (4, 8) is "directly or indirectly" attached to outer layer as well as to spacing elements (10) implies that it can be, but need not be an intermediate layer between these elements. Such intermediate elements can for example be a moisture barrier, sidewalls or the like. The need for moisture barrier is present for a construction element according to the present invention when it is to be used between a room that will be heated in a cold season and a room or a side that is not to be heated. In the usual manner the moisture barrier will be arranged on the warm side of the insulation of such a construction element.

Figure 1 shows a construction element 1 according to the present invention intended for use in a floor/ceiling construction. The construction element comprises an upper structure 2 consisting of an upper external layer 3 in the form of flooring boards or the like and a (not mandatory) upper plate 4 as well as upper sidewalls 5 extending along both long-sides of the upper structure 2. Upper plate 4, when being present, typically covers the entire area of the upper structure while the flooring boards constituting external layer 3 in sum do the same. The flooring boards can be of any material such as wood, wooden fibres, synthetic, cork etc. In other embodiments the external layer 3 can also comprise ceramic flooring tiles.

At a distance form the upper structure is a lower structure 6 with substantially the same horizontal area, comprising a lower, external layer 7 which can be ceiling boards, ceiling panel, ceiling plates or the like, a lower plate 8 and longitudinally extending sidewalls 9 extending parallel to upper sidewalls 5.

Between upper 5 and lower sidewalls 9 at both sides of the construction element, and rigidly attached to said sidewalls, spacing elements 10 typically in the form of one or more plates that together, but not necessarily continuously, extend(s) along most of the length at each side of the construction element. Also upper and lower sidewalls extend along substantially the entire length of the construction element. Upper and lower sidewalls 5, 9 have milled out grooves if a width corresponding the thickness of the spacing elements 10. The spacing elements are attached to the sidewalls with any suitable method or combination of methods, such as but not limited to, gluing, nailing, or screwing. The width of the spacing elements largely decides the thickness of the construction element and is chosen based on the requirement with respect to moment of inertia for the relevant application. A person skilled in the art will know that the moment of inertia is proportional to third power of the element thickness and adapt the choice of material and thickness based on the requirement for moment of inertia in the relevant application.

Upper and lower structure are attached to one another via the spacing plates 10, but can also be attached to one another by other means such as mountings, struts etc. in any suitable manner to obtain a convenient, structural strength and integrity. Upper plate 4 and lower plate 8 as well as the spacing plates 10 can be made in any material able to take up shear stress, while plates made of plywood or other hard materials which are simple to manufacture and easy to attach to the sidewalls, are particularly preferred. Plates of hard synthetic materials are also well suited as is metal plates.

Between the longitudinal lower sidewalls 9 crossbars 11 with through openings 12 are arranged with certain intervals, said openings being intended to receive pretensioning elements 13 which can be used to pull and firmly hold together construction elements across their length direction to thereby increase the moment of inertia of the resulting floor/ ceiling structure in the direction perpendicular to the length direction of the construction elements. Corresponding crossbars are arranged also between the upper sidewalls 5. A person skilled in the art will readily understand that there is a need for holes in the upper 5 and lower 9 sidewalls corresponding to the openings 12 in the crossbars 11. The crossbars 11 will typically be wooden but can also be made in other materials. To allow a higher degree of pretensioning than would else have been possible, each of the openings 12 may be provided with a sleeve 14 in a material stronger than the crossbars themselves. Such a material can typically be steel or other metal. Between upper and lower structure insulating elements 13a and 13b, which can be of same or different materials, are shown. For example the insulating layer 13a can be made in a material which is specifically chosen for its ability of optimal thermal insulation while insulating material 13b can be made in a material which is chosen due to its resistance properties against fire and heat. It need not, however, be more than one layer of insulating material. There may also be insulating layers 14 laterally outside each of, or at least one of the spacing plates 10.

The elements can furthermore comprise an upper or lower moisture barrier which can be a separate layer (not shown) or it can be inherent properties of a glue that is used to attach the upper or lower plate to upper, external layer 3 or lower, external layer 1 respectively, or the moisture barrier can be inherent in the upper and/ or lower plate. Fgiure 2 shows a construction element 1 ' according to the invention in an embodiment intended for use in a roof construction. The construction element 1 ' is principally similar to construction element 1 designed for use in a floor/ceiling construction, the main difference being that the upper, external layer 3' is a layer suitable for use as part of a roof and hence waterproof. In a completed building construction the external surface of the construction element 1 ' will still be covered by roofing tiles or roofing plates which rest on furring strips which again rest on the roof construction according to the present invention. To support such furring strips the upper, external layer is preferably provided with longitudinal lists on top of the upper, external layer. Figure 3 shows two construction elements 1 ' which are hinged together to a pair with a hinge 15 at the end of the construction elements which in mounted condition will face towards and be part of the roof ridge. Two thus hinged together construction elements 1 ' constitute a hinged ridge roof element. At the hinged end of each such construction element 1' there is typically formed an inclined end surface 17, the angle of which relative to upper, external surface and lower, external surface decides to what degree the hinged ridge roof element can be opened before said end surfaces rest against each other; generally less than 180 degrees, defining a lower limit for the angle of the roof construction. At or near the free end of each said construction element 1' there is arranged a brim16 designed in one embodiment to rest against a brim, list, or flange on the framework on which the roof is intended to rest.

Figure 4 shows how a floor/ceiling construction is in the process of being assembled on top of walls 21 and provided with pretensioning elements 18 which are pushed into the through openings 12 in the sidewalls 5, 9 and crossbars 11. It is preferred that the pretensioning elements 18 have a length which mainly corresponds to the width of the construction elements 1, 1' and is spliced by the means of threads for each new construction element that is assembled to an already positioned and pretensioned construction element. It is convenient to use washers between the heads or extensions on the pretensioning elements and the sidewalls 5 and 9 to thus avoid that the heads or extensions on the pretensioning elements sink into the woodwork (or other material) of the sidewalls 5 and 9. While the construction elements themselves have the required moment of inertia in their longitudinal direction, the pretensioning elements 18 provide the required moment of inertia in the direction perpendicular to the longitudinal direction. The pretensioning elements 18 at the lower structure 6, i.e. which extend through lower sidewalls 9 and lower crossbars 11 , take up the tensile stress that naturally occur at the lowermost side of a floor or a floor/ ceiling structure that is put under a certain load from above. The pretensioning elements through upper sidewalls 5 and crossbars balance "out" the pretensioning at the lower structure. The dimensioning of the pretensioning elements and the degree of pretensioning influence on the moment of inertia of the floor/ceiling construction across the length extension of each construction element 1.

A completely assembled floor/ceiling construction according to the invention will thus have properties of a large, stiff plate that exhibits large resistance against deflection in all directions, i.e. both in the length direction of the elements, perpendicular to the length direction and diagonally. As a roof construction the same is principally obtained, but with the difference that there are to hinged-together stiff plates that both lie in a plane deviating from the horizontal plane. In spite of the deviation from the horizontal plate, the side of each element that faces out of the completed building construction is denoted the upper side and the side forming an inclined ceiling is denoted the lower side. There is, however, to quite different methods for assembly of the roof construction depending upon whether the building is provided with gable walls and a ridge beam or just is laid on top of a flat ceiling or floor/ceiling construction.

In Figure 5 is illustrated how a roof construction according to the present invention is assembled on top of load-bearing gable walls and a not mandatory ridge beam. Near the free end of each ridge roof there is a brim 16 (ref. Fig. 3) that rests against an upward brim 21 of a building wall 22. When the roof construction according to the present invention is attached to both gable walls and sidewalls the roof construction contributes to forming a rigid box that also stabilizes the walls of the building. The load is evenly distributed to the walls and it is thus not a problem that some parts of the walls do not have the same ability to take up load, such as the parts over doors and windows. The construction as shown in Figure 5 provides an open solution with a high ceiling and complete and adequate insulation when the elements are conveniently dimensioned and insulated as earlier described. Figure 6 shows another embodiment where the roof is laid on top of a ceiling 25 which may or may not be a floor/ ceiling structure according to another aspect of the present invention. Along each of the walls 26, 27 where the free ends of the construction elements of the present invention which are assembled to a roof construction according to yet another aspect of the present invention rest, there are on top of the ceiling arranged a solidly attached rail 28 or brim in the entire extension of the ceiling. This implies that all forces that is applied to any element of the roof construction are effectively taken up in the length direction of the element with no risk of pointwise overloading of the wall below. Since the construction elements are solidly attached to one another in a manner which to not allow a parallel mutual displacement of the elements, each side of the roof will behave like a stiff plate. When a heavy load is applied to the roof, typically in the form of excessive snow, high forces will occur at the ridge, why the hinges of each pair of construction element must be well dimensioned to endure such forces. With increased weight on the o

roof construction according to Figure 6, there will be a tension in the ceiling 25 which contributes to make it even more resistant against deflection than without such a load applied from the roof construction to the ceiling.

Figure 7 illustrates construction elements 1 ' forming a roof construction which is put on top of a wall 26 in an "open" solution, somewhat like that of Figure 5, but which is not dependent on load-bearing gable walls. Along upper edge of the wall 26 (and similarly on top of not shown, opposite wall) there is arranged a rail 28 in the same manner as shown in Figure 6. With certain intervals wires or tensile rods, preferably via turnbuckles, are attached between the rail 28 and a rail on the opposite wall. The construction elements 1 ' are provided with solid attachment members in the form of continuous or discontinuous brim, rail 16' or the like, arranged to interact with a part of the rail 28 when the roof construction has been mounted. The wires or the tensile rods together with the optional turnbuckles can, if so desires, be embedded in hollow profiles that extend between said walls. In Figure 7 the construction element V is apparently a compact, homogenous structure, but it should be understood that it may be a construction element according to the first aspect of the present invention. Furthermore the. wall 26 in Figure 7 is shown as a wall assembled from a number of horizontal logs, like in a cogged wall, but it will be apparent to a person skilled in the art that the principle of Figure 7 is independent of the type of wall used. Common for the two solutions according to Figure 5 and Figure 6 is i.a. that the load transmitting member 16 near the free end of the construction elements has the form of a brim or a flange suitable to rest against a rail 28, a shoulder, a brim, a groove or a flange on or in a floor/ceiling construction, a balk or any other load-bearing element of a building construction. It is preferred that the construction elements according to the present invention is mass produced and mounted in fixture. Such a production will allow use of robots in the production.

In the space between upper and lower structure elements 13a 13b for thermal insulation, sound insulation and fire resistance will typically be arranged as mentioned above. Different insulating elements can be used to accomplish the different aspects of insulation. For example can a layer of fire retardant be arranged adjacent to the upper and lower structure and thicker layers of sound and thermal insulating materials between the fire retardant layers. The fire retardant layers can be plates of gypsum or other inflammable materials with low thermal conductivity. The sound and thermal insulating material can be any per se known material suitable for insulation of construction elements, such as but not limited to, polyurethane foam, polyester foam, phenolic foam, rock wool or woven glass fabric. It is preferred that all insulating materials with respect to recycling is provided as one or more uniform structures (plates) that can be removed in whole pieces when the element subsequent its period of use is cut through or in other manners opened, since this will render it easy to completely separate the different types of materials for recycling when a building construction is demolished.

As illustrated by Figure 8, it is especially preferred that the insulating material is provided with channels 31 and 31 suitable for easy installation of electrical cables in a hidden electrical installation. To obtain a maximum freedom of positioning of electrical units a main channel can extend along any construction element and through the sidewalls 5 and 9 so that on assembly of a number of construction elements 1 a continuous main channel 31 is formed. In an other direction and preferably perpendicular to the main channel and in open communication with same, a number of secondary channels 32 extend in the length direction of the construction element and preferably in substantially the entire length of the construction element. In Figure 8 the channels 31 and 31 are shown in the layer 13b and to provide a more complete illustration a flap of the layer 13b is "cut away" which naturally will not be the case in a construction element to be used.

When the construction element is an element for a roof construction the upper, external layer can be comprised by roofing felt (tar paper) or the like and longitudinal fittings can be attached along one long side to subsequent assembly cover the joint to the adjacent construction element. Furthermore there may be lists d or corresponding elements attache on top of the upper, external layer intended as a basis, directly or indirectly, for roofing tiles or roofing plates

The present construction elements are intended to be assembled to a floor/ceiling construction or a roof construction but may also be assembled to a wall construction.

A completed construction in the form of a floor/ ceiling structure according to the present invention can have a dimension typically in the range 6-8 meters or more in one direction and a dimension which in practice is unlimited in a direction perpendicular to the first direction, the construction elements being dimensioned with a length corresponding to the smallest dimension (the width) of the floor/ceiling construction. With elements of a length as mentioned it is easy to dimension the different components of a floor/ceiling construction according to the present invention so that a load of 100 kg/ m² implies a largest deflection of maximum 3 mm.

The construction elements according to the present invention can be produced with modules adapted to national or regional construction standards, e.g. with a width of 60 cm or more. For the assembly pretensioning elements in the form of bolts or tie rods are used. Generally the pretensioning elements 18 comprise a rod with a screw head at one end and external threads for a nut at the opposite end as well as a corresponding nut. Some pretensioning elements can instead of a screw head comprise female threads suitable for interaction with external threads of another pretensioning element 18. Furthermore the pretensioning element 18 typically can comprise washers suitable for distribution of the force on a larger area of the construction elements.

With respect to elements for a roof construction pairs of elements are typically hinged together at the factory prior to packaging and shipment and packed with the upper, external layer facing outwards. For assembly at the construction site the elements can be provided with removable mountings that are so shaped as to be readily attached to a crane for lifting of the elements to their place of a building construction during raising.

Each element will with a length of 8 meters and a width of 60 cm typically have a weight of about 200 kg and two hinged together elements of a roof construction, each of about 6 meters, will typically have a weight of about 300 kg. The elements are typically lifted to their place of assembly with a crane and moved to position entirely adjacent to a previously positioned element with a tool that does not constitute part of the present invention. Such a tool can be a pretensioning element designed particularly for the purpose or a tool that is specifically designed for this purpose. The construction elements can largely be produced after specifications and wishes from the customer. For example the upper, external layer of a construction element intended to a floor/ceiling construction can be delivered with a pre-applied floor covering, such as e.g. parquet or other covering and the lower, external layer can be delivered correspondingly complete, e.g. painted with a paint according to the customer's wish. When it is stated that the construction element according to the present invention comprises through openings 12 intended to receive pretensioning elements it is to be understood that such pretensioning elements already during manufacture, wholly or partially, may be arranged in each of the construction elements that is delivered for assembly. By "wholly or partially" in this context is understood that the pretensioning elements may comprise a number of components that at the construction site must be assembled to a uniform structure suitable to pretension the construction elements of the invention.

With respect to the production it is convenient that all construction elements of a certain dimension are identical with one another. This is, however, not a mandatory feature of the present invention. It is thus fully possible to use construction elements of at least two different types that need to be laid every second in order that the pretensioning elements fit together. In this case it is a possibility that one type of elements has a pre-positioned pretensioning element in all through openings while the other type of construction element does not have any pre-positioned pretensioning element. A number of other combinations are also available within the scope of the present invention. It is furthermore possible in some embodiments to use pretensioning elements in some openings, but not all openings suitable for receiving pretensioning elements. It is, though, most convenient to position the openings 12 at such intervals that an adequate pretensioning is obtained when pretensioning elements are used in all openings and tensioned to a certain torque.

Claims

1. Extended, layered construction element (1) comprising an upper structure (2) with an upper, external layer (3) and a lower structure (6) comprising a lower, external layer (7) said upper and lower structures (2, 6) being rigidly attached to one another via spacing elements (10), characterized in that through openings (12) for receiving pretensioning elements (18) are arranged with defined intervals across the length extension of the construction element nearthe upper, external layer (3) and near the lower, external layer (7), while inside at least one of upper, external layer and lower, external layer a plate (4, 8) is arranged to take up shear stress, said plate (4, 8) covering substantially the entire layer (3 resp. 7) and is directly or indirectly attached to said layer as well as to said spacing elements (10).

2. Construction element (1) as claimed in claim 1 , characterized in that the spacing elements (10) comprise at least two spacing plates (10) extending in the length direction of the construction element, perpendicularly arranged to the upper and lower structure (2 and 6 resp.) near each side edge of the construction element (1).

3. Construction element (1) as claimed in claim 2, characterized in that said spacing plates (10) extend in substantially the entire length of the construction element (1).

4. Construction element (1) as claimed in claim 2 or 3, characterized in that said spacing plates (10) are attached to upper (2) and lower structure (6) via longitudinally extending sidewalls (5 and 9 resp.) constituting part of upper (2) and lower structure (6) respectively and extending in the longitudinal direction along each side edge of the construction element (1).

5. Construction element (1) as claimed in claim 4, characterized in that the spacing plates (10) are attached to said sidewalls (5, 9) in longitudinal grooves being milled out in the sidewalls, the sidewalls (5,9) being attached to the other parts of upper (2) and lower structure (6) in any suitable manner.

6. Construction element (1) as claimed in any one of claims 2-5, characterized in that the spacing plates (10) are made in plywood, a synthetic or other material in plate shape suited to take up shear forces.

7. Construction element (1) as claimed in any one of claims 1-6, characterized in that the through openings (12) across the construction element are at least partially surrounded of crossbars (11) arranged perpendicular to said spacing plates (10).

8. Construction element (1) as claimed in any one of claims 1-7, characterized in that a space limited by an upper (2) and lower structure (6) as well as by said spacing plates (10) is at least partially filled with an insulating material (13).

9. Construction element (1) as claimed in any one of claims 1-8, characterized in that a space limited by an upper (2) and a lower structure (6) as well as by said spacing plates (10) are at least partially filled with a fire retardant material.

10. Construction element (1) as claimed in any one of claims 1-9, characterized in that a moisture barrier is arranged as part of the upper (2) and lower structure (6) which is designed to lie on a warm side of the construction element.

11. Construction element (1) as claimed in any one of claims 1-10, characterized in that the construction element is provided with tongue and groove along respective long sides, close to the upper, external layer of the construction element.

12. Construction element (1) as claimed in any one of claims 1-11 , characterized in that the construction element is provided with tongue and groove along respective long sides, close to the lower, external layer of the construction element.

13. Construction element (1) as claimed in any one of claims 1-10 or 12, characterized in that the construction element is provided with preferably rounded plugs along one long side and corresponding holes in the opposite long side, close to the upper, external layer of the construction element.

14. Construction element (1) as claimed in any one of claims 1-11 or 13, characterized in that the construction element is provided with preferably rounded plugs along one long side and corresponding holes in the opposite long side, close to the lower, external layer of the construction element.

15. Construction element (1) as claimed in any one of claims 1-14, characterized in that the construction element constitutes en element of a floor/ceiling construction, wherein the upper, external layer has the form of a floor surface while lower, external layer has the form of a ceiling surface.

16. Construction element (1) as claimed in claim 15, characterized in that the upper, external layer is constituted by flooring boards, flooring panel or flooring tiles.

17. Construction element (1) as claimed in claim 15 or claim 16, characterized in that the lower, external layer is constituted by ceiling boards, ceiling panel or ceiling plates.

18. Construction element (1) as claimed in claim 1 , characterized in that the plate (4, 8) being arranged to take up shear forces, is a plate made in plywood or in a synthetic or other material suitable for taking up shear forces when shaped as a plate.

19. Construction element (1) as claimed in claim 1 , characterized in that it comprises a layer, such as an insulating layer (13b) in which a number of interconnected channels (31 , 32) are arranged in two different directions for allowing easy installation of hidden electrical or other cables subsequent the assembly of construction elements (1) to a construction.

20. Construction element (1) as claimed in any one of claims 1-14, characterized in that the construction element constitutes part of a roof construction and at one side is provided with a hinge device arranged to be hinged to a corresponding construction element with a corresponding hinge device, such hinged couples of construction elements (T) constituting hinged ridge roof elements.

21. Construction element (1) as claimed in claim 20, characterized in that each couple of construction elements (T) forming a hinged, combined ridge roof element, is arranged to be folded out to a maximum angle less than 180 degrees, said angle being decided by the form or shape of the end surfaces (17) of said construction elements (T) on the short sides where they are hinged together.

22. Construction element (1) as claimed in any one of claims 20-21 , characterized in that the construction element (1 ') close to the free, not hinged, short side, at its lower structure, is provided with a first load transmitting member (16) suited to cooperate with a corresponding load transmitting member (28) on upper part of a building construction on which the construction element is arranged to be supported.

23. Construction element (1) as claimed in claim 22, characterized in that the first load transmitting member (26) has the shape of an edge, a groove or flange arrange to interact with a rail (28), a shoulder, an edge, a groove or a flange on or in a floor/ ceiling structure, a beam or other load-bearing element of a building construction.

24. Construction element (1) as claimed in any one of claims 20-23, characterized in that the upper external layer is a layer of roofing felt (tar paper).

25. Floor/ ceiling structure for building constructions, characterized in that it is comprised by a number of construction elements (1) comprising an upper structure (2) with an upper, external layer (3) and a lower structure (6) with a lower, external layer (7), said upper and lower structure being rigidly attached to one another with spacing elements (10) while each construction element (1) is provided with at least one horizontal plate (4, 8) arranged to take up shear stress, said construction element being provided with through openings (12) across the length direction of the element, arranged in lines and with defined intervals near the upper, external layer (3) and near the lower, external layer, said through openings enclosing pretensioning elements (18) arranged to hold the construction elements (1) pretensioned with a force so as to form a rigid, uniform floor/ ceiling structure.

26. Floor/ ceiling structure as claimed in claim 25, characterized in that at least some of the pretensioning elements (18) each comprises a bolt with a screw head at one end and external threads for a nut at the opposite end as well as corresponding nut.

27. Floor/ ceiling structure as claimed in claim 26, characterized in that at least some pretensioning elements (18) instead of a screw head comprise female threads arranged to interact with external threads in another pretensioning element (18).

28. Floor/ ceiling structure as claimed in one of claims 26-27, characterized in that at least some of the pretensioning elements (18) comprise washers suited to distribute the force on a larger area of the construction elements (1).

29. Roof construction comprising a ridge roof with two roof surfaces and an intermediate ridge, characterized in that the roof construction is assembled of construction elements

(1¹) as defined by claim 20, first hinged in pairs in the length direction of the construction element (1 ') whereafter a number of such pairs of hinged construction elements are assembled across their length direction, the roof construction further comprising a number of pretensioning elements (18) inserted in through openings (12) across the length direction of the construction elements to establish a pretensioning of the construction elements (1 ') across their length direction to provide the roof bending strength in all directions.