Building element and roof construction

Abstract

 Building element, more particularly for roof, wall or floor constructions, wherein this building element (1) is at least composed of a basic board (2) and a top board (3), between which insulation material (4) is located, and wherein said boards (2-3) are provided with one or more ribs (5), characterized in that said basic board (2) and top board (3) are acoustically uncoupled. The invention also relates to a roof construction (9), wherein such building elements (1) are attached onto the truss (10) such that at least said top board (2) is acoustically uncoupled in respect to the truss (10).

Description

[0001] This invention relates to building elements or building panels, as well as to a roof construction making use of such building elements.

[0002] The known building elements or building panels substantially exist in two types. On the one hand, there is the so-called open-shell building element, wherein only at one flat side of the building element or building panel a basic board is applied and wherein the other flat side, namely, the open side, substantially is formed by the insulation material itself, and, on the other hand, the closed or sandwich building element, wherein a top board is provided at the second flat side, such that the insulation material is located in the space between the basic board and the cover board. For examples of open-sided roof elements and closed or sandwich roof elements, reference is made to EP 0 978 601 and EP 1 162 050.

[0003] More particularly, the invention relates to building elements or building panels of the closed type, which can be applied as roof elements. Namely, more particularly this relates to building elements of the type which is at least composed of a basic board and a top board for providing batten laths thereon, wherein insulation material is located between said basic board and said top board, and wherein said boards are provided with one or more ribs.

[0004] Such building elements or building panels are already widely known and may be realized, for example, as an insulating self-supporting roof element. In this respect, reference is made, for example, to EP 0 450 731 or EP 1 253 257. Such roof elements may be provided with their basic board on a simply constructed roof framework, for example, a roof framework only with girders. After installing such roof elements, these mostly also are provided with roof laths, which in their turn support the roof tiles or other roof cladding. In such construction, the roof element fulfils the function of a traditional insulated roof underlay. It is also possible that said basic board forms the interior covering of the respective roof construction or that the basic board is provided with such interior covering. Usually, such roof elements are pre-fabricated to size for a house.

[0005] The building elements of the above-mentioned type, which are known from the state of the art, show an excellent heat-insulating effect, however, are less suitable for acoustic insulation.

[0006] From CH 601 598 and DE 34 37 446, insulation elements are known of another than the above-mentioned type. Herein, only one board is used. Moreover, in this case only a single reinforcement rib is attached on this basic board. Such insulation elements have a limited carrying capacity. In both documents, the height of the reinforcement rib is kept smaller than or equal to the thickness of the insulation material, and said basic board is directed outward. With DE 34 37 446, said reinforcement rib, in order to obtain a better acoustic insulation, is constructed of two layers, namely, a first layer consisting of an insulation material having a limited carrying capacity, for example, of hard foam, and a second layer consisting of a material with a high pressure resistance. The insulation elements are connected to the truss by means of long nails, which are driven through the carrying board and the reinforcement ribs. This attachment manner partially eliminates the acoustic insulation of the two-layered reinforcement ribs, as said basic board now is connected to the truss via the rigid nails.

[0007] From DE 200 16 828 U1, an insulation element of the above-mentioned type is known, wherein the top board is acoustically uncoupled from the basic board. The acoustic uncoupling is obtained in this case in that they are connected via ribs which are composed of two layers, namely, a first layer, which consists of an insulating material, and a second layer, which consists of a material having a high pressure strength. The compartments bordered by the ribs and the basic and top boards are filled with insulation material. Such element provides only a limited acoustic uncoupling.

[0008] From NL 1009690, an insulation element of another than the above-mentioned type is known. Here, this relates to an element for a roof construction which comprises a top board for attaching batten laths thereon, however, which is free from a basic board. The insulation material and the ribs are attached to the bottom side of the top board. Thus, the element is attached onto the roof construction, and the insulation material thus forms the contact side with the truss. Such construction leads to deformations of the insulation material around the girders and other parts or unevennesses of the truss.

[0009] From DE 41 01 234, an insulation element is known of another than the above-mentioned type, wherein only one board is applied and no use is made of reinforcement ribs, but still of a plurality of attachment laths, which are embedded in the insulation material. To this aim, these laths extend in the transverse direction of the insulation element. Such insulation element has a limited carrying capacity. When using the building element, the basic board is fixedly attached to the truss, for example, by means of screws or nails.

[0010] From BE 1017639, an insulation element is known of another than the above-mentioned type, wherein only one board is applied and no use is made of reinforcement ribs. The board concerned is on one side entirely glued onto the insulation material. Such element is not self-supporting, but cooperates with ribs which have to be provided separately.

[0011] From CH 670 673 and CH 644 921, also insulation elements are known of another than the above-mentioned type, wherein then only one board is applied and wherein the reinforcement ribs present are not attached to the basic board, but come into contact with a web-shaped sealing film or entirely are embedded in the insulation material, respectively. In the case of CH 644 921, the side of the roof element which is directed inward during installation, is formed by the insulation material or possibly by a sealing film provided on the insulation material, whereas in the case of CH 670 673, the inwardly-directed side is formed by the basic board.

[0012] From BE 1016469, a sound-insulating roof construction is known wherein strip-shaped insulation material is provided between carriers, which as such are composed of a lath and a strip provided thereon. The so-called acoustic strip is composed of a material which absorbs vibrations, such as of coconut material. The roof construction is provided with boards, which are attached to the laths and strips by means of screws or nails, and is finished further with a layer of covering boards. Such construction is very cumbersome.

[0013] From WO 01/16440, a sound-insulating wall construction is known. The building elements mentioned there are not suitable for roof constructions.

[0014] With the intention of obtaining an improved acoustic insulation, in particular with building elements or building panels of the above-mentioned type, the present invention, according to various independent aspects thereof, relates to novel building elements, which, due to their separate or combined inventive characteristics, contribute to an increased sound resistance, or, in other words, to an increased acoustic insulation and/or to an increased strength of the element. According to various preferred embodiments, the invention offers a solution for one or more disadvantages of the building elements of the state of the art.

[0015] According to a first independent aspect, the invention relates to a building element for a roof construction, wherein this building element is at least composed of a basic board and a top board for providing batten laths thereon, wherein insulation material is located between said basic board and said top board, and wherein said boards are provided with one or more ribs, with the characteristic that said basic board and top board are acoustically uncoupled. As a result of said boards being acoustically uncoupled, sound waves impacting on one of the two boards, for example, on the board directed outward in the roof construction, will propagate to a lesser extent to the other board, for example, to the board directed inward in the roof construction. Such acoustic uncoupling may be realized in a variety of ways. For example, it may be provided for that the two boards are connected to each other via compressible material only. Both boards can also be elastically connected to each other in another manner, for example, by the intermediary of one or more torsion springs or leaf springs. By "compressible material", material is intended which is more compressible than the material of said ribs. According to the first aspect of the present invention, such acoustic uncoupling of both boards is achieved in a practical manner in that the basic board is connected to the top board substantially via the insulation material. By this, it is intended that the pressure stiffness of the building element, under pressure load perpendicularly to one of the boards, substantially is determined by the pressure stiffness of the insulation material. Preferably, the basic board is connected to the top board exclusively via the insulation material. Herein, it is obtained that a pressure load perpendicularly to one of said board is transferred to the other of said boards substantially or exclusively via the insulation material and thus not, or principally not, via said ribs. Said ribs, however, may serve as a reinforcement with a possible bending load or torsion load, and thus in this manner contribute to the stiffness of the element. For example, the ribs limit a possible sagging of the element and may determining for the maximum obtainable bridging of such building element. Preferably, at least one of said boards is attached to the insulation material by means of a flat glue connection.

[0016] According to a preferred embodiment of the aforementioned first aspect, the possible distance between said rib and the basic board differs from the possible distance between said rib and the top board. Herein, said distance is seen in cross-section of the building element and measured perpendicularly to one of said boards. It is clear that according to this preferred embodiment, said possible distance possibly may be non-existent or may be as good as non-existent. By the arrangement of the present preferred embodiment, an acoustic uncoupling can be combined with a good bending stiffness. As the material of the ribs is situated closer to one of the boards, a larger moment of inertia during bending is obtained.

[0017] Preferably, the building element of the invention is oblong, and preferably said ribs extend in the longitudinal direction of the building element. Preferably, two or more of such ribs are applied, wherein these ribs preferably are located internally in the building element and thus do not form a lateral edge thereof, although this is not excluded. Preferably, the insulation material, at least for a part thereof, is located between said two or more ribs. Preferably, such ribs consist of wooden beams preferably having a rectangular cross-section. Of course, it is not excluded to work with another material than wood, and/or that another cross-section for these ribs is opted for, such as a cross-section similar to the cross-section of an I-profile. Preferably, between the ribs a lateral distance of at least 30 centimeters and still better of at least 40 centimeters is maintained.

[0018] According to a preferred embodiment, said rib, or said two or more ribs, are attached to said basic board or top board without intermediate insulation material. The ribs concerned may be attached, for example, by means of nail, screw and/or glue connections and/or by any other attachment means. By the direct attachment of the ribs to at least one of the boards, namely, without intermediate insulation material, it is obtained that the ribs, under a bending load, can absorb the applied forces in a good manner. Moreover, according to this preferred embodiment, a simple construction of the building element is achieved. As is evident from the above, according to the invention, the ribs concerned preferably are connected directly to only one of said boards. Preferably, the ribs concerned are not at all connected to the other board, although it is possible that they are connected to the insulation material, for example, laterally, for example, by means of a glue attachment, wherein the insulation material then in its turn can be connected directly or indirectly to the other board. Such lateral connection of the ribs with the insulation material, however, hardly has any influence on the acoustic properties of the building elements or on the pressure strength or pressure stiffness of the building element. However, this lateral connection of the ribs with the insulation material may have a positive influence on the stiffness of the building element during bending and/or torsion.

[0019] Preferably, at least one of the boards, for example, the top board, is separated from said rib by an air chamber. Possibly, instead of air also another material can be applied, which is more compressible than said insulation material, such as a gel or a liquid, which is located, for example, in a closed deformable receptacle.

[0020] Preferably, at least the basic board and/or at least the top board substantially consists of wood-based board material, such as a multiplex board, OSB board (Oriented Strand Board), a wood particle board, a wood fiberboard, such as MDF or HDF (Medium Density Fiberboard or High Density Fiberboard). Other board materials are possible, too, such as flax particle board, sandwich-type plasterboard, concrete fiberboard, gypsum fiberboard or silicate board. The material applied for the basic board and/or the top board may show the feature that it is made waterproof and/or fire-retardant, such as can be the case with wood particle board. The top board and the basic board preferably have a thickness of at least 6 millimeters and still better of at least 8 millimeters. Possibly, the top board can be made thicker than the basic board.

[0021] Preferably, as insulation material a cellulose-based insulation material or an insulation material based on wood fiber is applied. Cellulose-based insulation materials are renowned for their good acoustic insulation value; moreover, they also have an acceptable up to very good thermal insulation value. The cellulose-based insulation material either can be provided dry in the building element, as a separate layer, or can be provided in the building element as a viscous liquid substance, after which it was hardened or dried. Insulation materials based on wood fiber also show good acoustic insulation values in combination with an acceptable up to very good thermal insulation value. Preferably, so-called wood fiber insulation boards are used. Herein, the wood fibers, for example, may be connected to each other by means of a polyolefin. It is also possible that this insulation material is provided with fire-retardant additives, such as with one or more inorganic nitrogen-containing mineral acids. For example, the houtFlex insulation boards marketed by the company HOMATHERM® are highly suitable for application in the building elements of the present invention according to all of its aspects.

[0022] Of course, instead of cellulose or wood fiber, also other insulation materials may be used, such as flake foam, which comprises, for example, foam flakes connected by means of polyurethane, wherein these foam flakes are obtained, for example, as a waste product in the production of mattresses or couches.

[0023] Possibly, also the typical thermally insulating materials can be used, such as an insulation foam chosen from the series of polyurethane, polyisocyanurate, polystyrene, extruded polystyrene, expanded polystyrene phenol insulation, perlite, vermiculite and glass foam, or an insulation material chosen from the series of mineral wool, such as glass wool or rockwool, wood wool, flax wool, sheep's wool and feathers, such as duck feathers or the like. In the case of glass wool, a significant fire-retardant effect is obtained, and in the case of an insulation material of animal origin a very environmentally-friendly building element is obtained.

[0024] According to a preferred embodiment, the building element of the invention has an acoustic resistance (Ra) of at least 40 dB(a) and/or at least a thermal resistance (Rc) of 4 m²K/W. Such insulation values can be obtained with an insulation material on the basis of cellulose, wherein this insulation material as such has a thickness between 10 and 20 centimeters.

[0025] Preferably, at least one of said boards, preferably the board directed outward in the roof construction or the top board, is realized heavier than the other of said boards. Making this board heavier results in a better acoustic resistance. For example, as the outwardly-directed board, a board can be applied having a thickness of 12 millimeters or more, such as a board of 18 millimeters or more, whereas the other board is realized thinner. As already mentioned, it is possible that, amongst others, the inwardly directed board is finished at the respective side with decorative material, for example, with a laminate layer, laths or the like.

[0026] According to another preferred embodiment, it is the board directed inward in the roof construction or the basic board, which is made heavier than the other of the aforementioned boards. Making this board heavier results to a reduced emission of transferred sound. For example, as an inwardly directed board, a board can be applied having a thickness of 12 millimeters or more, such as a board of 18 millimeters or more, whereas the other board is made thinner. The inwardly directed board further may be made heavier by the presence of decorative material, intended for interior finishing. The inventor has booked good results with a 12 millimeter basic board, which further also had been provided with a sandwich-type plasterboard as interior finish. By such element, sound reductions of 50 dB(A) can be achieved.

[0027] According to another preferred embodiment of the invention, the building element is oblong and is provided with two or more ribs extending in the longitudinal direction of said basic board, wherein insulation material is located between said ribs, and wherein, viewed in a cross-section of the building element, there is a difference between the height of at least one of the ribs and the thickness of the insulation material, wherein the height of said rib is smaller than the thickness of the insulation material and wherein the possible distance between said basic board and said rib is smaller than one half of said difference. Herein, said distance is viewed in cross-section of the building element and measured perpendicular to said board. It is clear that according to this preferred embodiment, said possible distance may be non-existent or as good as non-existent. Preferably, said possible distance is smaller than 40% or still better smaller than 30% of said difference.

[0028] According to an independent second aspect, the invention also relates to a roof construction which results in a better sound insulation. To this aim, the invention relates to a roof construction, wherein this roof construction comprises one or more building elements of the type comprising at least a board, ribs and insulation material located between these ribs, wherein said building elements are attached directly or indirectly to the truss, with the characteristic that the building elements are attached to the truss such that at least said board is acoustically uncoupled in respect to the truss. It is clear that herein, the building elements of preceding aspects can be applied, however, this is not necessarily so. According to the second independent aspect, use can also be made of building elements which, as such, comprise only one board, or, in other words, there is no top board available. As will become clear from the detailed description, it is possible to realize an acoustically uncoupled roof construction with such building element, too. Preferably, such building element is oblong and provided with two or more ribs, which extend in the longitudinal direction of said basic board, wherein insulation material is located between said ribs, and wherein, seen in a cross-section of the building element, there is a difference between the height of at least one of these ribs and the thickness of the insulation material, wherein the height of said rib is smaller than the thickness of the insulation material and wherein the possible distance between said basic board and said rib is smaller than one half of said difference. Herein, said distance is viewed in the cross-section of the building element and measured perpendicular to said board. It is clear that in such case said possible distance can be non-existent or as good as non-existent. Preferably, said possible distance is smaller than 40%, or still better smaller than 30% of said difference. By limiting the possible distance between the ribs and the basic board, it can be achieved that said ribs are arranged asymmetrically in respect to the neutral fiber during bending load. Hereby, an increased moment of inertia during bending is obtained. For preferred embodiments of a roof construction according to the second aspect, reference is made to the detailed description.

[0029] Preferably, the building elements of the invention are self-supporting. This means that such building elements can form a self-supporting construction, or, in other words, in such construction are able to carry their own weight without any considerable deformation. This property may result in very simple constructions.

[0030] With the intention of better showing the characteristics of the invention, hereafter, as an example without any limitative character, some preferred embodiments are described, with reference to the accompanying drawings, wherein:

Figure 1 in perspective represents a building element having the characteristics of the invention;

Figure 2, at a larger scale, represents a cross-section according to the line II-II indicated in figure 1;

Figures 3 to 7, in a similar view, represent variants;

Figure 8 in perspective represents a roof construction having the characteristics of the invention;

Figure 9, at a larger scale, represents a cross-section according to the line IX-IX in figure 8;

Figures 10 and 11, at a still larger scale, represent a view according to the areas F10, F11, respectively, indicated in figure 9, wherein figure 11 represents a variant;

Figure 12, in a view similar to that of figure 9, represents a variant;

Figure 13, at a larger scale, represents a view to the area F13 indicated in figure 12;

Figure 14, in a view similar to that of figure 10, represents another variant of a roof construction;

Figures 15 and 16, in a view similar to that of figure 1, represent some other preferred embodiments of building elements according to the invention; and

Figure 17 represents a cross-section according to the line XVII-XVII represented in figure 16.

[0031] Figure 1 represents a building element 1, more particularly a roof element or roof panel, having the characteristics of the first aspect of the present invention.

[0032] The roof element 1 of figure 1 is composed of a basic board 2 and a top board 3, between which insulation material 4 is located. Herein, said boards 2-3, in this case, the basic board 2 only, are provided with ribs 5. In the example, use is made of three ribs 5, which extend in the longitudinal direction of the oblong building element 1. In respect to the insulation material 4, for example, use can be made of cellulose-based material. Possibly, the insulation material 4 as such can be composed of a plurality of layers, whether or not consisting of the same material. Such multi-layered composition of the insulation material 4 is not represented here.

[0033] The top board 3, which is intended for being directed outward in a roof construction, is provided with batten laths 6 attached thereto, which batten laths also extend in the longitudinal direction of the element 1. The batten laths 6, for example, may be glued onto the top board 3, as it is the case here, or can be attached thereto by means of nails or screws. Of course, a combination of said attachment techniques is possible, too. Such batten laths 6 can be provided in all embodiments of the present invention, whether or not already during the production of the building element 1. They do not necessarily, as is the case in the example, have to be provided in positions which correspond to said ribs 5. In roof constructions in which the longitudinal direction of the building elements 1 is parallel to the width of the roof construction, it is, of course, possible that the batten laths 6 extend perpendicular to the longitudinal direction of the element 1. In such case, the batten laths 6 preferably are attached to the element only when it already has been incorporated in the roof construction.

[0034] The building element 1 of figure 1 shows various particular characteristics. A first particular characteristic consists in that the top board 3 is acoustically uncoupled from the basic board 2. This feature is obtained in this case in that the top board 3 is in contact with the insulation material 4 only. Thus, the top board 3 is connected to the basic board 2 in an elastic manner. Hereby, it is obtained that sound waves, which reach the top board 3 and penetrate into the building element 1, have to propagate substantially, if not exclusively, via the insulation material 4. By using an acoustic insulation material 4, such as wood fiber insulation board, a high absorption of the sound waves in the building element 1 can be obtained, such that the possible remaining sound emitted by the basic board 2 can be restricted.

[0035] The connection of the top board 3 with said insulation material 4 is in this case at least partially, and here even entirely, obtained in that the top board 3 is glued flat onto the insulation material 4.

[0036] Figure 2 clearly shows a second particular characteristic of the building element 1, namely, that the basic board 2 is connected to the top board 3 via the insulation material 4, and that in other words, the ribs 5 thus do not connect these boards 2-3 directly, as this is the case with the sandwich elements from the state of the art, for example, with the elements of EP 0 450 731, EP 1 253 257 and EP 1 162 050. Preferably, said top board 3, as is the case here, is connected to said insulation material 4 by means of a glue connection 7. Preferably, the lower board 2 is also connected to this insulation material 4 at least by means of a glue connection 7. In the example, said glue connection 7 with the insulation material 4 is not performed over the entire surface of the boards 2-3, but is interrupted at the height of the ribs 5. The large surface of the boards 2-3 in self-supporting elements 1, however, results in a sufficient strength of the glue connection 7 with the insulation material 4 in order to take up, for example, possible wind loads.

[0037] It is clear that the pressure strength or pressure stiffness of the represented element 1, under a load perpendicularly to one of the boards 2-3, is determined substantially by the pressure strength or pressure stiffness of the insulation material 4, and thus not or practically not by the pressure strength or pressure stiffness of the applied ribs 5. In the represented example, an elastic connection between the boards 2-3 is obtained.

[0038] Figure 2 also represents that the ribs 5 are connected to the basic board 2 and preferably also to the insulation material 4 located in between by means of glue connections 7. However, these glue connections 7 have little or no influence on said pressure stiffness or pressure strength of the element 1, but indeed a positive influence on the resistance against possible bending and/or torsion loads.

[0039] From figure 2, a third particular characteristic becomes clear, namely, that the possible distance x1 between the ribs 5 and the basic board 2, which here is non-existent or as good as non-existent, differs and, in the example, is smaller than the distance x2 between these ribs 5 and the top board 3. In the example of figure 2, the ribs 5 namely are connected to the basic board 2 via a glue connection 7, whereas no connection, but indeed an air chamber 8 is present between these ribs 5 and the upper board 3. This property leads to an improved acoustic insulation in combination with a good bending stiffness.

[0040] From the above, it is clear that the building element 1 of figures 1 and 2 also shows a fourth particular characteristic, namely, that there is a difference between the height H of the ribs 5 and the thickness D of the insulation material 4, wherein the height H of the ribs 5 is smaller than the thickness D of the insulation material 4 and wherein the possible distance x1 between said basic board 2 and the ribs 5 is smaller than one half of said difference. In this case, this possible distance x1 is non-existent or almost non-existent, as the ribs 5 are attached directly onto the basic board 2 by means of a glue connection 7. In respect to the height H of the ribs 5, it is also noted that these do not necessarily all have to be of the same height, however, preferably all have such a height that an acoustic uncoupling between top board 3 and basic board 2 remains possible.

[0041] It is noted that a building element or roof element 1, such as the one of figure 1, in practice may show a length L which may be a plurality of times the width B thereof. The length L can be provided according to the size of the roof construction and preferably is between 2 and 8 meters, whereas the width B of the element 1 depends on the number of ribs 5 the roof element 1 is showing, wherein a width B situated between 60 and 150 centimeters is preferred. Herein, the overall height A of a roof element 1 preferably can be chosen between 7 and 25 centimeters. The overall thickness D of the insulation material 4 then corresponds thereto.

[0042] Said basic board 2 and/or top board 3 may be chosen, for example, from the series of wood particle board, sandwich-type plasterboard, plaster fiberboard, multiplex board, OSB board (Oriented Strand Board) and silicate board.

[0043] Said ribs 5 or strips preferably consist of wood, such as spruce wood or pine wood, and preferably extend over the entire length L of the roof element 1. Preferably, each rib 5 in longitudinal direction consists of a single piece and preferably has a thickness of 20 to 45 millimeters. Instead of being composed of a single piece, one or more of said ribs 5, in the longitudinal direction thereof, also can be composed of a plurality of parts, for example, by attaching shorter ribs to one another. Such attachment can be performed by means of a so-called finger joint. For an example of such technique, reference is made to the already named EP 1 162 050. It is noted that the basic board 2 and/or the top board 3 also can consist of parts joined together.

[0044] It is expected that by means of a building element 1, such as that from figure 1, wherein such acoustically uncoupled top board 3 is provided, an acoustic resistance value of Ra=44 dB(a) can be achieved, whereas a thermal resistance of Rc=4 m²K/W is achieved, whereas from experiments with a quasi identical, however, not uncoupled element, constructed according to the state of the art, namely, wherein the ribs connect the basic board and the top board, an acoustic resistance value of Ra=35 dB(a) only is resulting. Thus, the acoustic uncoupling of the invention provides for a very significant improvement of the sound-insulating properties of building elements 1.

[0045] Figure 3 represents a variant, wherein ribs 5 are attached to the basic board 2 as well as to the top board 3. Herein, it is obtained that the connection between the top board 3 and the insulation material 4 can resist wind loads even better. Possibly, such building element 1 also shows an improved bending and/or torsion stiffness. It is clear that this element 1 also shows the already above-mentioned particular characteristics.

[0046] Figure 4 represents a further variant, wherein the configuration of the ribs 5 is such that the basic board 2 and the top board 3 show comparable, if not identical mechanical properties. Thus, in the example, this relates to an entirely symmetrically constructed building element 1, wherein on the basic board 2 as well as on the top board 3, ribs 5 are provided. In the present case, the ribs of the basic board 2 are separated from the ribs 5 of the top board by an air chamber 8, which provides for said acoustic uncoupling. It is clear that good results may also be obtained with other materials, which are situated at the locations of the air chamber 8 represented here. Preferably, however, a material is applied which has a smaller pressure strength of pressure stiffness than said ribs 5 and/or the insulation material 4. For example, the insulation material 4 itself can be applied or a material with a still smaller pressure strength or pressure stiffness. It is clear that the building element of figure 4 shows the characteristics of the first aspect of the present invention.

[0047] Figure 5 shows another variant, wherein the ribs 5 are not directly attached to the basic board 2 or the top board 3, but are situated in the mass of the insulation material 4. Such element as well shows all particular characteristics mentioned herein above, however, in comparison to the elements 1 of figures 1 through 3 results in a lesser bending stiffness.

[0048] It is noted that with the building elements 1 of the invention it is not necessary to work exclusively with glue connections 7 for connecting the boards 2-3 and/or ribs 5 with the insulation material 4. One or more connections can have been realized by the insulation material 4 itself. This may be the case, for example, when working with polyurethane, which, in the production of the building element 1, is foamed on one of the boards 2-3, between both boards 2-3 and/or between the ribs 5. During testing, the connection obtained between foamed polyurethane and particle board has proven stronger than a separate glue connection between particle board and, for example, glass wool. One or more connections can have been realized by mechanical connecting means, such as by means of barbs, which grip into the insulation material. It is clear that all these connecting techniques can be combined with each other.

[0049] Figure 6 represents another variant, wherein a heavy top board 3 is applied, wherein this top board 3 preferably is made heavier than said basic board 2. For example, OSB board having a thickness of 18 mm or more could be used. Furthermore, the element 1 is made identical to the building element 1 represented in figures 1 and 2 and thus shows the same particular characteristic as the element 1 from those figures. By means of such element 1, an acoustic resistance value of Ra=50 dB(a) can be achieved. It is clear that also particularly effective acoustic resistance values can be obtained when the basic board is made heavier than the top board.

[0050] Figure 7 represents a deviating variant of a roof element. Such roof element can be applied, for example, in a roof construction having the characteristics of the second aspect of the invention mentioned in the introduction. Herein, in this case, this relates to an element 1 which is realized almost identical to the element 1 from figures 1 and 2, however, which is not provided with a top board 3. From the further detailed description, it will become clear that such element 1 also can result in an inventive roof construction having a good sound-insulating effect. Such element 1 is particularly interesting for renovating existing roof constructions, wherein these roof constructions, for example, already comprise a cover consisting of boards, or any other roof floor, roof underlay or underlay board, which is provided on the truss, for example, on the outer side thereof. Such formwork, roof floor, roof underlay or underlay board prevents deformations of the insulation material in this deviating variant, when the insulation material is applied as a contact side with the existing roof construction.

[0051] Figure 8 represents how the roof element 1 from figure 1 can be applied in a roof construction 9. Herein, it can be started from a relatively simple roof framework 10, such as represented, wherein a limited number of girders 11 is used, onto which then the roof elements 1 are attached. As represented, the further roof covering 12 then can be provided on these roof elements 1. For example, as represented here, roof tiles can be provided after roof laths 13 have been provided. Herein, the roof laths 13, in the example, are attached to the batten laths 6 or battens. Although in the example the building elements 1 extend with their longitudinal direction from the gutter to the ridge, it is possible, according to a variant of such roof construction 9, to place the building elements 1 such that they extend with their longitudinal direction in the width of the roof construction 9. This is crosswise to the orientation of these elements 1 represented here. It is clear that with such crosswise orientation, the orientation of the remaining portions of the roof construction, such as the batten laths, the roof laths and the girders, preferably is performed unaltered, such as represented in figure 8.

[0052] Figure 9 clearly represents the composition of the roof construction 9 from figure 8. As is clear from the larger representation of figure 10, it is possible to attach the building elements 1 on the roof framework 10 without eliminating the acoustic uncoupling of the top board 3 and the basic board 2. To this aim, for example, U-shaped clamps 14 can be used, which are beaten with one extremity into the ribs 5 and with another extremity are beaten through the basic board 2 into the roof framework 10 or girders 11. In order to render the rib 5 accessible, in the case of figure 10 locally a hole 15 is provided in the top board 3. This may be realized, for example, by means of a holesaw. Such holes 15 may or may not be provided already during the production of these building elements 1. It is clear that by this manner of working, a roof construction 9 can be obtained having the characteristics of the second aspect of the invention. Instead of using such hook-shaped clamps 14, also two interconnected screws or nails can be used, of which one engages in the rib 5, whereas the other penetrates into the roof framework 10 or girder 11. In such case, the connection between the screws or nails can be realized, for example, by driving the respective screws or nails through a common connection element, which preferably is situated above said rib 5. Said holes 15 preferably are made air-tight again after attaching the clamps 14, for example, by placing caps therein.

[0053] Figure 9 shows that possible seams 16 between the roof elements 1 mutually can be finished both longitudinally as well as transversely, for example, by filling them with an insulation material 17, such as polyurethane foam. Such finishing also maintains the acoustic uncoupling between top board 3 and basic board 2.

[0054] Figure 11 represents a variant, wherein mechanical coupling means 18 are provided on the sides of the roof elements 1. In the example, the edges are provided with a profile, for example milled, in such a manner that they allow realizing a connection of a tongue 19 in a groove 20 among two adjacent building elements 1. Here, too, the remaining seam 16 is finished further with an insulation material 17, such as polyurethane foam.

[0055] Figure 12 shows how the building elements 1 of figure 7 can be applied for obtaining a roof construction 9 having a good sound-insulating effect. The roof construction 9 comprises a separately provided board-shaped covering 21, which is attached onto the roof framework 10 or the girders 11. This can be the case, for example, when renovating an existing roof construction. The building elements 1 from figure 7 are fixed thereon by directing them with their basic board 2 outwards. Due to the presence of the board-shaped covering 21, the risk of impressing or other deformation of the insulation material is minimized, by which an optimum sound reduction can be maintained. In the obtained result, the basic board 2 of the building element 1 is acoustically uncoupled from the board-shaped covering 21.

[0056] Figure 13 represents that also in the case of the building elements 1 of figure 7, it is possible to prevent an acoustic coupling between the basic board 2 and the separate board-shaped covering 21 and in this manner realize a roof construction 9 having the characteristics of the second aspect of the present invention. In the example of figure 13, this is realized in that the nails or screws 22 applied are connected to the basic board 2 via a compressible material 23. To this aim, for example, a material 23 can be used having a compressibility which is closer to that of the insulation material 4 than to that of the ribs 5.

[0057] Figure 14 represents another view on a roof construction, which is very similar to that of figure 10. In this case, however, use is made of alternative attachment means instead of the U-shaped clamps 14 represented in figure 10. In this case, the attachment means comprise a screw 24 and a bracket 25, which in this case engages in the rib 5 as well as in the insulation material 4. Further, the hole 15 here is sealed again with a cap 26. Further, it is noted that in the example, the batten laths 6, instead of vertically above the ribs 5, here are provided on the top board at a certain horizontal distance from these ribs 5, such that the holes 15 do not have to interrupt these batten laths 6.

[0058] Figure 15 shows that the top board 3 of the building element 1 can be provided with holes, via which the ribs 5 are locally accessible to the attachment means 14-24-25. Figure 15 also shows that to this aim preferably the batten laths 6 are provided on the top board 3 at a position where they are shifted over a certain horizontal distance in respect to the ribs 5. Preferably, with such building element also caps 26 are supplied, which fit into said holes 15. According to a particular independent aspect, the present invention also relates to a building element 1, more particularly for roof, wall or floor constructions, wherein this building element 1 is at least composed of a basic board 2 and a top board 3, between which insulation material 4 is located, and wherein said boards 2-3 are provided with one or more ribs 5, with the characteristic that at least one of said ribs 5 is free from contact with at least one of said boards 3, and that this respective board 3, in this case, the top board 3, is provided with at least one hole 15, by which the rib 5 can be reached, independently of the fact whether any acoustic uncoupling has been achieved or provisions have been taken to this end. Preferably, each rib 5 has been made accessible by means of such hole 15 at least at one location. Still better, one or more of all ribs 5 have been made accessible 0.5 to 5 times per meter by means of such hole 15. It is clear that the respective holes 15 preferably are positioned at least partially vertical above said ribs 5. Preferably, said top board 3 is provided with batten laths 6, wherein these batten laths 6 preferably are positioned on a location which is displaced horizontally in respect to said ribs 5, such that they do not have to be interrupted in order to reach the ribs 5. Said holes preferably have a shape of which the diameter of the smallest inscribed circle is situated between 20 and 50 millimeters. The invention further also relates to a kit which comprises at least a building element according to this particular independent aspect and moreover comprises at least caps 26, which can be applied for sealing said holes 15. Preferably, said caps 26 allow obtaining a water-and/or air-tight sealing of the hole 15. Preferably, this relates to synthetic material caps, which effect such sealing already by fitting into the holes. Preferably, the kit of the invention also comprises attachment means, such as the above-mentioned attachment means. It is clear that the building element 1 of said particular independent aspect further also can show the characteristics of the above-mentioned first aspect and/or one or more of the preferred embodiments thereof, and that such building element 1 possibly can be applied for obtaining a roof construction 9 having the characteristics of the second aspect of the invention mentioned in the introduction.

[0059] Figure 16 represents a further particular possibility, which can be applied in the building elements 1 of the invention according to any aspect or preferred embodiment thereof. Herein, at least the side 27 of the building element 1, which is intended to be directed towards the roof gutter in the roof construction 9, thus, away from the ridge of the roof, is provided with a portion 28 which minimizes or even excludes the risk of a possible sliding off of the top board 3. As in some preferred embodiments, the top board 3 is connected to the insulation material 4 by means of a flat glue connection 7 only, this risk is real.

[0060] Figure 17 clearly represents that in this case a strip 29, for example, a wooden lath, is attached transversely on the ribs 5. This strip 29 forms a stop for a possible sliding off of said top board 3. Between this strip 29 and the top board 3 in this case also a piece 30 of compressible material is provided.

[0061] Referring to the figures 16 and 17, it is also noted that the present invention, according to a second particular independent aspect, relates to a building element 1, more particularly a building element 1 for roof, wall or floor constructions, wherein this building element 1 is at least composed of a basic board 2 and a top board 3, between which insulation material 4 is located, and wherein said boards 2-3 are provided with one or more ribs 5, with the characteristic that at least one of said boards 2-3 is connected at least partially, substantially or only by means of a glue connection 7 to the insulation material 4 and that the building element 1 is provided with means 28, which minimize the risk of the respective board 3 sliding off, such independently from the fact whether any acoustic uncoupling has been obtained or measures have been taken to this end. It is clear that such means can comprise a strip 29 and/or a piece of compressible material, which extend transversely over the ribs 5, such as it is the case in the figures 16 and 17. Further, it is clear that such means can be applied in any also above-mentioned building element. It is also clear that the building element of this second particular aspect can be applied in the roof constructions of the second aspect mentioned in the introduction.

[0062] Generally, it is also noted that said ribs 5, in the production of such building element 1, do not necessarily have to be provided on the respective board 2-3 prior to adding the insulation material 4 to the building element 1. It is also possible to provide recesses in or between the insulation material 4, in which recesses the ribs 5 afterwards can be fixed. For example, a technique similar to the technique known from EP 0 978 601 can be applied.

[0063] Further, it is also noted that where a basic board 2 and/or a top board 3 is mentioned, these preferably, however, not necessarily, are intended to be directed outward, inward, respectively, in the roof construction 9.

[0064] Further, it is clear that the building elements 1 of the invention can comprise any number of ribs 5 and that this number can vary from one to five or more, wherein these ribs 5 preferably all extend in the longitudinal direction of the building element 1. Preferably, the ribs 5 have a rectangular cross-section, wherein they are attached with one of the smallest sides of this cross-section on said boards 2 or 3, as it is the case in all examples represented here. Hereby, it is clear that the ribs 5 in the building elements 1 of the invention cannot be compared to roof laths 13, battens 6, attachment laths or the like. Moreover, preferably they have a larger cross-section than such laths, roof laths 13 or battens 6. Contrary to laths, roof laths 13 or battens 6, the ribs 5 which are applied in the building elements 1 of the invention, preferably show at least the feature that they are free or almost free from deformation by bending when they have a length of more than 5 meters and support their own weight. Preferably, the ribs 5 applied according to the invention have at least a cross-section which is larger than 10 square centimeters and still better is larger than 20 square centimeters. It is known that laths, roof laths 13 and battens 6 generally have a section which is smaller than 8 square centimeters. Preferably, the ribs 5, seen in cross-section, have a height H which is at least one half of the overall thickness A of the building element 1. However, this is not necessarily so. For example, in the case of a building element similar to the building element of figure 4, this may also be less than one half of the overall thickness A. Preferably, the ribs 5, in such case, too, have a height H which is at least one fourth and still better one third of the overall thickness A of the building element 1.

[0065] It is evident that the uncoupling attachment techniques, which are obtained by means of figures 9 to 14, mutatis mutandis also can be applied for obtaining wall or floor constructions having excellent sound-insulating properties. It is clear that the present invention, according to a variant of said second aspect, also comprises such wall or floor constructions.

[0066] The present invention is in no way restricted to the embodiments described herein above; on the contrary, such building elements and roof constructions can be realized according to various variants, without leaving the scope of the present invention. So, for example, is it possible to apply the invention with so-called curved building elements. These are characterized in that said basic board and/or top board are curved according to an arc with a radius of, for example, 2 to 10 meters, and this preferably around an axis which is parallel to the longitudinal direction of the building element. These building elements are suitable, for example, as an acoustic roof element in a roof construction which has a certain rounding. Preferably, such roof elements extend with their longitudinal direction in the width of the roof construction.

Claims

1. Building element for a roof construction, wherein this building element (1) is at least composed of a basic board (2) and a top board (3) for providing batten laths (6) thereon, wherein insulation material (4) is located between said basic board (2) and said top board (3), and wherein said boards (2-3) are provided with one or more ribs (5), characterized in that said basic board (2) and top board (3) are acoustically uncoupled, wherein the basic board is connected to the top board via the insulation material.

2. Building element according to claim 1, characterized in that the possible distance (X1) between said rib (5) and the basic board (2) differs from the possible distance (X2) between said rib (5) and the top board (3).

3. Building element according to claims 1 or 2, characterized in that the building element (1) is oblong and that said ribs (5) extend in the longitudinal direction of the building element (1).

4. Building element according to any of the preceding claims, characterized in that said rib (5) is attached onto said basic board (2) without intermediary insulation material (4).

5. Building element according to any of the preceding claims, characterized in that the top board (3) is separated from said rib (5) by an air chamber (8).

6. Building element according to any of the preceding claims, characterized in that at feast the basic board (2) and/or at least the top board (3) consists of wood-based board material.

7. Building element according to any of the preceding claims, characterized in that said insulation material (4) relates to a cellulose-based insulation material or an insulation material based on wood fibers.

8. Building element according to any of the preceding claims, characterized in that one of said boards, either said top board (3) or said basic board (2), is realized heavier than the other of said boards (2-3).

9. Building element according to any of the preceding claims, characterized in that this building element (1) has an acoustic resistance (Ra) of at least 40 dB(a) and/or has at least a thermal resistance (Rc) of 4 m²K/W.

10. Roof construction, wherein this roof construction (9) comprises one or more building elements (1) having the characteristics of preceding claims, wherein said building elements (1) are attached directly or indirectly onto the truss or onto the roof framework (10), characterized in that the building elements (1) are attached to the truss (10) such that at least said board (2-3) is acoustically uncoupled in respect to the truss (10).

11. Roof construction according to claim 10, characterized in that instead of using the aforementioned building elements (1), a building element is used which shows the following characteristics, namely, that this building element (1) is oblong, comprises at least a basic board (2) for providing batten laths (6) thereon and is provided with two or more ribs (5) extending in the longitudinal direction of said basic board (2), and wherein insulation material (4) is located between said ribs, wherein, seen in a cross-section of the building element (1), there is a difference between the height (H) of at least one of the ribs (5) and the thickness (D) of the insulation material (4), wherein the height (H) of said rib (5) is smaller than the thickness (D) of the insulation material (4) and wherein the possible distance (X1) between said basic board (2) and said rib (5) is smaller than one half of said difference, and wherein the roof construction further is characterized in that the roof construction comprises a board-shaped covering (21), that said insulation material (4) comes into contact with this board-shaped covering (21) and that said acoustic uncoupling consists in an acoustic uncoupling of said basic board (2) and said board-shaped covering (21).

12. Roof construction according to claim 11, characterized in that said ribs (5) are connected to the insulation material (4) via glue connections (7).

13. Building element, more particularly for roof, wall or floor constructions, wherein this building element (1) is at least composed of a basic board (2) and a top board (3), between which insulation material (4) is located, and wherein said boards (2-3) are provided with one or more ribs (5), characterized in that at least one of said ribs (5) is free from contact with at least one of said boards (3) and that this board (3) concerned is provided with at least one hole (15) via which the rib (5) can be reached.

14. Building element, more particularly for roof, wall or floor constructions, wherein this building element (1) is at least composed of a basic board (2) and a top board (3), between which insulation material (4) is located, and wherein said boards (2-3) are provided with one or more ribs (5), characterized in that at least one of said boards (2-3) is connected to the insulation material (4) at least partially by means of a glue connection (7) and that the building element is provided with means (28), which minimize the risk of the respective board (3) of sliding off.

15. Building element according to claim 14, characterized in that said means (28) comprise at least a strip (29) and/or a piece of compressible material (30), which extend transversely over the ribs (5).

Drawing