DK2678491T3

DK2678491T3 - Roof beam and prefabricated roof element with roof beams

Info

Publication number: DK2678491T3
Application number: DK12714553.0T
Authority: DK
Inventors: Peehr Mathias Ørnfeldt Svensson
Original assignee: Svensson Peehr Mathias Ornfeldt
Priority date: 2011-02-25
Filing date: 2012-02-22
Publication date: 2015-07-20
Also published as: CN103562474B; WO2012113406A1; EP2678491B1; EP2678491A1; PL2678491T3; CN103562474A

Description

DESCRIPTION

Field of the Invention [0001] The present invention concerns a roof girder of the kind indicated in the introduction of claim 1.

[0002] The invention also concerns a prefabricated roof plate element with one or more roof girders according to the invention. Background of the Invention [0003] Prefabricated roof girders and roof plate elements, respectively, of this kind can be made of 100% inorganic materials which is very significant to durability and maintenance. Besides, it is of great significance that the roof plate elements in question can have a free span of up to 22 metres, i.e. one single roof plate element may cover about 80 m2, which of course is very essential with regard to reducing the construction time.

[0004] EP 2 145 056 A1 (W02008/125109A1) describes a prefabricated roof plate element, including one or more longitudinal box-shaped roof girders that each consists of two predominantly U-shaped metal sections which at mutually facing, open sides are interconnected along narrow outwards bent lateral edges, the roof girders being connected at upper and lower narrow sides corrugated in longitudinal direction with metal plates corrugated in transverse direction and having approximately the same width as the roof plate element, the roof girders/support girders and roof plate element, respectively, designed with reduced height at an end part intended to form eaves.

[0005] WO 02/092937 A1 discloses a method of handling and joining at least two sectional steel elements together to form a load-bearing beam element, preferably for interaction with a separately-formed post footing, a beam element made from at least two sectional elements, and a beam element/post footing combination. The method being characterised in that detached angle section elements are joined together to form a hollow sectional beam, and that at least one sleeve plate is externally attached around the hollow sectional beam thus obtained and is locked to this forming stop for receiving preferably board-shaped elements.

Object of the Invention [0006] It is the purpose of the invention to indicate a further improved roof girder of the kind mentioned in the introduction and a further improved roof plate element which by means of simple technical measures may entail very substantial projecting advantages, and which furthermore has appeared to enable an architecturally very simple and light construction of the visible part of the roofing on a building. In addition, at the same time is furthermore achieved that the roof girder and the roof plate element according to the invention in a simple way are provided the required space for meeting the raised requirements to insulation, i.e. meet the current standards of the building regulation to reduced λ- and U-values (coefficient of thermal conductivity and thermal conductivity, respectively).

Description of the Invention [0007] The roof girder according to the invention is peculiar in that the metal sections at the lower and lower open sides, respectively, are interconnected by means of a plurality of connecting plates which are fastened to inner, substantially vertical sides of the metal sections in such a way that there is a spacing between the narrow outwardly bent edges of respective lower and upper metal sections; that the cavity is filled with insulation material; and that the plurality of connection plates are provided at different positions along the rood girder. By means of simple technical provisions can hereby be achieved substantial projecting advantages and which furthermore have appeared to enable an architecturally very simple and light construction of the visible part of the roof plate on a building.

[0008] At the same time is furthermore achieved that the roof girder invention in a simple way is provided the required space for additional layers of insulating material in order to fulfil the raised requirements to insulation, i.e. meet the current standards of the building regulation to reduced λ- and U-values (coefficient of thermal conductivity and thermal conductivity, respectively), which particularly is due the fact that the thermal bridge known from prior art roof girders is effectively counteracted in that the metal sections are not directly connected with each other.

[0009] The roof girder according to the invention may at the same time be provided a significantly increased span of up to more than 24 metres in that the spacing between the narrow outwardly bent edges amount to 50-500 mm, preferably 100-200 mm. In that connection it is to be emphasised that due to the mutual spacing between upper and lower metal sections, a considerable reduction in the steel consumption between 20 and 50% can be achieved, compared with a prior art roof girder with correspondingly higher upper and lower metal sections.

[0010] A roof girder according to the invention may advantageously be designed such that a lower of the U-shaped metal sections is shorter than an upper of the U-shaped metal sections, and that the upper U-shaped section is closed downwards at a projecting end part intended to form eaves in a roof plate element by means of a preferably U-shaped metal section, which is disposed internally of the upper U-shaped metal section and fastened to the latter.

[0011] In some cases there is a desire for a lower extension, i.e. lower eaves, and in such case the lower metal section is longer than the upper metal section.

[0012] With the object of further simplifying mounting, the roof girder according to the invention may suitably be designed such that the connecting plates are constituted by prefabricated units, the width of which adapted to the internal width of the U-shaped metal sections, and the height and length of which varying in dependence on the height of the roof girder and the actual longitudinal disposition of the units in the roof girder.

[0013] In an embodiment, the roof girder according to the invention can be designed such that the prefabricated units are constituted by box-shaped units having a core of mineral wool or insulating foam, where the core is connected at opposing outer sides by metal plates with low thermal conductivity (U-value), the metal plates preferably externally being covered with an insulating layer of e.g. so-called integral foam (Figs. 7 and 8).

[0014] In an alternative embodiment, the roof girder according to the invention can be designed such that the prefabricated units are constituted by box-shaped units with opposing outer sides and transverse sides consisting of fibre-reinforced construction plates or composite plates, and which have a core of mineral wool or insulating foam (Figs. 9 and 10).

[0015] By a further alternative embodiment, the roof girder according to the invention can be designed such that the prefabricated units are constituted by box-shaped units with opposing outer sides and transverse sides consisting of fibre-reinforced construction plates or composite plates, and which have a core of mineral wool or insulating foam, the outer sides further provided with upper and lower metal plates disposed with vertical spacing (Figs. 11 and 12).

[0016] According to yet an embodiment, the roof girder according to the invention can be designed such that the connecting plates are constituted by connecting plates of metal or composite plates with low thermal conductivity (U-value) adapted to be connected with opposing vertical inner sides of the upper and lower U-shaped metal sections, and in the form of a transverse connecting partitioning integrated with the connecting plates.

[0017] With the intention of further reducing the heat conductivity and to obviate an actual thermal bridge, it may furthermore be advantageous that between the outer side of the connecting plates of metal or composite plates with low heat conductivity and the inner side of the vertical sides of the metal section there is provided a layer of non-woven material or other suitable intermediate layer of non-conducting material.

[0018] The invention additionally concerns a roof plate element of the kind indicated in the preamble of claim 9, the roof plate element being peculiar in that it includes an upper connection between the longitudinal roof girders, the connection consisting of a construction plate of inorganic and non-flammable material, a trapezoidal steel sheet or a sandwich panel, a layer of compression-resistant insulation, an upper roof membrane and an underside lining of laths and insulating plates.

[0019] In an alternative embodiment of a prefabricated roof plate element according to the invention, the underlining consists of trapezoidal sheets of steel or light-alloy metal, the sheets optionally including suitable insets of insulating material. The underlining may alternatively consist of ceiling boards of non-flammable, inorganic construction plates. The roof girders and the roof plate elements can be made with heights adapted to span and loads. According to the invention, it is possible to produce roof girders and roof plate elements with built-in slope to one or two sides (Figs. 23 and 24), implying a very great cost-saving as the roof slope is not to be built up on the construction site.

[0020] Moreover, roof girders and roof plate elements according to the invention all fulfil current standards for environmental sustainability and CC>2-saving, which is particularly due to the much prolonged service life because of the use of inorganic materials. In that connection it has furthermore appeared that the use of steel sections as load-bearing elements rather than e.g. laminated wood also gives a much increased service lift in addition to increased span.

[0021] An alternative application can be that girders and elements according to the invention can advantageously be used as fapade covering and as storey partitionings with a span up to even 15 metres.

Description of the Drawing [0022] The invention is explained more closely in the following with reference to the drawing, on which:

Fig. 1 shows a plan view of a cross-section of an embodiment of a roof plate element according to the invention with eaves at a side edge;

Fig. 2 shows a plan view of a longitudinal section of the roof plate element shown in Fig. 1 according to the invention;

Fig. 3 shows a plan view of a cross-section of a second embodiment of a roof plate element according to the invention;

Fig. 4 shows a plan view of a partial longitudinal section of the roof plate element shown in Fig. 3 according to the invention;

Fig. 5 shows a plan view of a cross-section of a third embodiment of a roof plate element according to the invention;

Fig. 6 shows a plan view of a partial longitudinal section of the roof plate element shown in Fig. 5 according to the invention;

Fig. 7 shows a perspective view of an embodiment of a connecting plate for a roof girder according to the invention;

Fig. 8 shows a perspective view of a lowermost steel section of a roof girder according to the invention with a connecting plate screwed on cf. Fig. 7;

Fig. 9 shows a perspective view of a second embodiment of a connecting plate for a roof girder according to the invention;

Fig. 10 shows a perspective view of a lowermost steel section of a roof girder according to the invention with a connecting plate screwed on cf. Fig. 9;

Fig. 11 shows a perspective view of a third embodiment of a connecting plate for a roof girder according to the invention;

Fig. 12 shows a perspective view of a lowermost steel section of a roof girder according to the invention with a connecting plate screwed on cf. Fig. 11;

Fig. 13 shows a perspective view of a prior art roof girder with an embodiment with a connecting plate;

Fig. 14 shows a perspective view of a roof girder according to the invention with an embodiment with a connecting plate;

Fig. 15 shows a plan view of a longitudinal section of a roof plate element with longitudinal eaves (cantilever and saddle notch) according to the invention;

Fig. 16 shows a perspective view of a roof girder with longitudinal eaves according to the invention with an alternative connecting plate;

Fig. 17 shows a perspective view of an alternative embodiment of a box-shaped connecting plate;

Fig. 18 shows a plan view of a cross-section through a roof girder according to the invention for illustrating use of the connecting plate shown in Fig. 17;

Fig. 19 shows an alternative embodiment of a connecting plate for a roof girder according to the invention;

Fig. 20 shows a plan view of a cross-section through an alternative roof girder where the thermal bridge effect in the metal section is reduced by means of lateral slits forming a labyrinth for the heat conducting path;

Fig. 21 shows a plan view of a part of a steel plate designed with rows of oblong lateral slits;

Fig. 22 shows an enlarged plan view of the lateral slits shown in Fig. 21;

Fig. 23 shows a plan view of a cross-section in a roof construction with a roof plate element with a slope according to the invention; Fig. 24 shows a plan view of a cross-section in a roof construction with a roof plate element sloping at two sides according to the invention;

Fig. 25 shows a perspective view of an alternative embodiment of a roof plate element with roof girders designed as lattice girders; Fig. 26 shows a perspective view of a roof girder designed as a lattice girder;

Fig. 27 shows a perspective view of side part of the roof girder shown in Fig. 26;

Fig. 28 shows a perspective view of an end fish plate connection to the roof girder according to the invention shown in Fig. 26;

Fig. 29 shows a perspective view of a plate strut to the roof girder shown in Fig. 26;

Fig. 30 shows a perspective view of the plate strut in Fig. 29, as seen from the opposite side;

Fig. 31 shows a perspective view of a solid insulation block for use in constructing a roof girder where struts of steel sheeting are fastened at the side of the insulation block by gluing before the insulation block is fastened between an upper and a lower U-shaped metal section;

Fig. 32 shows a perspective view of a solid insulation block for use in constructing a roof girder where struts of steel sheets with bent out side edges are fastened at the side of the insulation block by pressing in the side edges in the latter and by supplementary gluing;

Fig. 33 shows a perspective view of a solid insulation block for use in constructing a roof girder where mutually crossing struts of steel sheets are fastened at the side of the insulation block by gluing; and Fig. 34 shows a plan view of a joint between two roof plate elements to illustrate how a joint between mutually overlapping edges of vapour barrier can be assembled in an entirely pressure-tight way.

Detailed Description of the Invention [0023] Figs. 1 and 2 show sectional views of an embodiment of a roof plate element 2 according to the invention where side eaves 6 are established at a side of the roof plate element 2, as an outer protruding part 4 of the roof plate element 2 has reduced thickness which is produced by means of insert girders 5 supporting the upper extended part of the roofing, and which are inserted at the side of the roof plate element 2 and disposed in an interspace between upper reversed U-shaped metal sections 8 and lower U-shaped metal sections 10.

[0024] According to the invention, the upper and lower metal sections 8, 10 are not interconnected at the mutually facing narrow outwardly bent edges 14, 16. As the narrow outwardly bent edges 14, 16 have a vertical spacing A, roof girders 12 with increased height and thereby increased bending stiffness are thereby provided. In practice, the spacing A can vary between 50 and 500 mm, preferably between 100 and 200 mm.

[0025] Furthermore, the interspace 7 established between the metal sections 8, 10 provide for passing e.g. electric installations through tubes 9 provided in the interspace 7 (Fig. 2). Instead of the direct mechanical connection of the narrow outwardly bent edges 14, 16 which until now has been made by clinching (press joint), the mechanical assembly between vertical inner sides of upper and lower metal sections 8, 10 takes place by means of the connecting plates shown in Figs. 7 - 12, 14 and 16 -19, where each will be explained separately in detail in the following.

[0026] In a simple way, the required space for additional layers of insulating material is provided in order to fulfil the raised requirements to insulation, i.e. meet the current standards of the building regulation to reduced λ- and U-values (coefficient of thermal conductivity and thermal conductivity, respectively).

[0027] Figs. 1 - 6 show prefabricated roof plate elements 2 including one or more longitudinal roof girders 12 which are placed along opposing sides and at the centre between the opposing sides of the roof plate element 2 which includes an upper mechanical connection 18 between the longitudinal roof girders 12, the mechanical connection 18 consisting of a construction plate of inorganic and non-flammable material, a trapezoidal steel sheet or a sandwich panel, a layer of compression-resistant insulation 20, an upper roof membrane 22 and an underside lining 24 of laths 26 and insulating plates 30. Alternatively, the underlining 24 may consist of trapezoidal sheets 32 of steel or light-alloy metal and possibly insulation integrated in the trapezoidal sheets.

[0028] The cavities of roof girders 12 and roof plate elements 2 are filled with suitable insulation which, as most clearly shown in Figs. 1, 2, 3 and 5, provide that the longitudinal spacing A between the metal sections 8, 10 can get additional insulation, the thickness of which as spacing A can vary between 50 and 200 mm.

[0029] The mechanical connections between metal sections 8, 10 are most clearly shown in Figs. 4, 6 and 15 where the metal sections 8, 10 at opposite ends of the roof plate element 2 are joined by a relatively wide connecting plate 34 that provides space for ten screws 36 in each of the metal sections 8, 10 and the connecting plate 34, respectively. Besides, there is shown a narrower central connecting plate 36 with a width providing space for four screws 36 in each of the metal sections 8, 10 and the connecting plate 38, respectively.

[0030] In practice, the situation will be as follows by a roof girder 12 and a roof plate element 2, respectively, with a span of 24 metres. Connecting plates will have a length with space for (10-20) x 2 screws 36. Over the first 5 metres measured from each their end of the roof girder 12 and the roof plate element 2, respectively, there will be a spacing between narrow connecting plates of about 750 mm, where e.g. there is space for (4-6) x2 screws 36, whereas at the central about 14 metres, there will be a spacing of about 2000 mm between narrow connecting plates with space for (4-6) x 2 screws 36.

[0031] It is to be mentioned that connecting plates generally can be connected with the vertical inner sides of the metal profiles 8, 10 by means of gluing whereby the thermal conductivity can be further reduced.

[0032] Fig. 7 shows a box-shaped connecting plate 40 having a core 42 of mineral wool or insulating foam, where the core 42 is connected at opposing outer sides by metal plates 44 with low thermal conductivity (U-value), the metal plates 44 preferably externally covered with an insulating layer 46 of e.g. so-called integral foam. In Fig 8 is shows how connecting plate 40 has been mounted in a lower metal section 10 by means of eight screws 36 which are screwed from the outer side of the metal section 10 and through the latter and the insulating layer 46 and fastened in the metal plate 44.

[0033] Fig. 9 shows a second embodiment of a box-shaped connecting plate 48 with opposing outer sides and transverse sides consisting of fibre-reinforced construction plates 50, and which has a core 52 of mineral wool or insulating foam.

[0034] In Fig 10 is shows how connecting plate 48 has been mounted in a lower metal section 10 by means of eight screws 36 which are screwed from the outer side of the metal section 10 and through the metal section 10 and fastened in the construction plate 50.

[0035] Fig. 11 shows a third embodiment of a box-shaped connecting plate 54 with opposing outer sides and transverse sides consisting of fibre-reinforced construction plate 50 and having a core 52 of mineral wool or insulating foam, the outer sides further provided with upper and lower metal plates 56, 58 which are disposed with vertical spacing B which in practice will correspond to the spacing A between the narrow outwardly bent edges 14, 16 of the metal sections 8, 10.

[0036] In Fig 12 is shows how connecting plate 54 has been mounted in a lower metal section 10 by means of eight screws 36 which are screwed from the outer side of the metal section 10 and through the metal section 10 and fastened in the construction plate 50.

[0037] Fig. 13 shows a roof girder known per se where outwardly bent edges 14, 16 of the metal sections 8, 10 do not have any vertical spacing and where the previously used mechanical connection by clinching (press joint) is replaced by a connecting plate 60 fastened to each of the metal sections 8, 10 by means of 8 x 2 screws 36. Possibly, with regard to reducing the effect of a thermal bridge, non-woven material is placed between the inner sides of the metal sections 8, 10 and the outer side of the connecting plate 60.

[0038] Fig. 14 shows a roof girder 12 according to the invention where the mechanical connection between the metal sections 8, 10 that are disposed with spacing A is effected by means of a connecting plate 60 consisting of metal with modest heat conductivity, e.g. stainless steel. The latter is fastened to each metal section 8, 10 by means of 8 x 2 screws 36. Flere also, with regard to reducing the effect of a thermal bridge, non-woven material is placed between the inner sides of the metal sections 8, 10 and the outer side of the connecting plate 60.

[0039] Fig. 15 shows a roof plate element 2 with eaves 7 supported on a support in the form of a strong steel beam 11. The eaves 7 is established in that the roof girders 12 consist of an upper metal section 8 which has greater length than the lower metal section 10.

[0040] Fig. 16 shows a roof girder 12 according to the invention with eaves 7, i.e. the upper metal section 8 has greater length than the lower metal profile 10, where the mechanical connection between the metal sections 8, 10 disposed with spacing A is effected by means of a connecting plate 61 consisting of metal with modest heat conductivity, e.g. stainless steel. The latter is fastened to each metal section 8, 10 by means of 8 x 2 screws 36. Flere also, with regard to reducing the effect of a thermal bridge, non-woven material is placed between the inner sides of the metal sections 8, 10 and the outer side of the connecting plate 60.

[0041] Fig. 17 shows yet an alternative embodiment of a connecting plate 62 which is very similar to that of Figs. 11 and 12, as the opposing side plates 64 have greater height than the transverse plates 66, which is also shown in Fig. 18 showing a cross-section through a roof girder 12 where the side plates 64 are bearing directly against opposite short sides of the upper metal section 8 and the lower metal profile 10.

[0042] Fig. 19 shows a further embodiment for a connecting plate 68 which in a simple way can be made by shortening of a longer pre-bent metal section.

[0043] Figs. 20-22 show a completely alternative way of reducing the heat conductivity in a roof girder. Fig. 20 shows a cross-section through an upper part of a roof girder 70 where the mutually facing outwardly bent edges of an upper and lower metal section are directly connected in a known way, e.g. by clinching. The metal sections are made from coil sheets that have prefabricated lateral slits 72 disposed in relation to each other in such a pattern that a kind of labyrinth is formed with the object of increasing the heat conduction path through the side of the metal section, as indicated in Fig. 22 with broken line 74.

[0044] Fig. 23 shows a roof construction 76 with unilateral slope which is "incorporated" in the applied roof girders 78, i.e. the spacing increases upwards between upper inclined metal sections 8 and lower horizontal metal sections 10. At the bottom is used a standard connecting plate 34 whereas the other connecting plates are adapted to the increasing spacing between the metal sections 8, 10.

[0045] Fig. 24 shows a roof construction 80 with slope at two sides which is also "incorporated" in the applied roof girders 82. At opposing sides are used standard connecting plates 34 whereas the other connecting plates are adapted to the varying spacing between the upper inclined metal sections 8 and the lower horizontal metal sections 10.

[0046] Figs. 25-30 shows an alternative embodiment of a roof plate element 82 where three roof girders 84 are designed as lattice girders (Fig. 26) constructed from two U-shaped metal sections 8, 10 where between is mounted end fish plate connections 86 (Fig. 28) and plate-shaped struts 88 (Figs. 29 and 30).

[0047] Fig. 31 shows a block 90 of insulating material intended to be mounted directly between two U-shaped steel sections 8, 10 as the insulating block 90 previously has been provided with cross-braces 92 of steel sheeting which is glued to opposite sides of the insulation block 90, and which subsequently is connected with side edge parts of the U-shaped metal profiles 8, 10 by means of screws.

[0048] Fig. 32 shows a corresponding block 90 of insulation material where cross-braces 94 consist of steel sheeting, where opposite side edges 96 are bent in a right angle and where the cross-braces 94 are fastened to opposite sides of the block 90 by fitting the side edges 96 into the block and possibly by supplementary gluing..

[0049] Fig. 33 shows yet a block 90 of insulation material where intersecting cross-braces 98 are fastened to opposing sides of the block 90 by gluing before this as mentioned above is fastened between U-shaped metal sections 8, 10.

[0050] Fig. 34 shows an edge joint between two roof plate elements 100 where between lower adjacent side edges 102 of respective roof plate elements 100 there is established a good pressure-tight connection between overlapping side edges 104 of vapour barrier 106.

REFERENCES CITED IN THE DESCRIPTION

This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

Patent documents cited in the description • EP2145056A1 [0904] • WO20JJ812510.¾A1. [0004] . WQ02092937A1 100051

Claims

A roof beam (12) consisting of two predominantly U-shaped metal profiles (8, 10), the lower and upper open sides respectively facing each other, forming a cavity therebetween and formed with narrow outwardly curved edges (14, 16), said roof beam (12) being longitudinally corrugated at opposite upper and lower sides, characterized in that said metal profiles (8, 10) are connected to said upper and lower open sides, respectively, by means of a plurality of connecting plates (34) fixed for interior predominantly vertical sides of the metal profiles (8, 10) in such a way that there is a distance (A) between said narrow outwardly curved edges (14, 16) of respective lower and upper metal profiles (8, 10); that the cavity is filled with insulating material; and that a plurality of connecting plates (34) exist at different positions along the roof beam.

Roof beam (12) according to claim 1, characterized in that said distance (A) between said narrow outwardly curved edges (14, 16) is 50-500 mm, preferably 100-200 mm.

Roof beam (12) according to claim 1, characterized in that a lower of said U-shaped metal profiles (10) is shorter than an upper of said U-shaped metal profiles (8) and that the upper U-shaped metal profile (8) ) at a protruding end portion intended to form overhangs (7) in a roof plate element (2) is closed downwardly by a preferably U-shaped metal profile located internally in said upper U-shaped metal profile (8) , and attached to it.

Roof beam (12) according to claim 1, characterized in that said connecting plates are made of prefabricated units whose width is adapted to the internal width of said U-shaped metal profiles and whose height and length vary depending on the height of the roof beam and the concrete units. longitudinal placement in the roof beam.

Roof beam according to claim 4, characterized in that said prefabricated units are constituted by box-shaped units having a core of mineral wool or insulating foam, which core at opposite outer sides is connected to low thermal conductivity (U-value) metal sheets, which metal sheets are preferably externally coated with an insulating layer, for example of so-called integral foam (Figs. 7 and 8).

Roof beam according to claim 4, characterized in that said prefabricated units are made up of box-shaped units, the opposite outer and transverse sides of which consist of fiber-reinforced building plate or composite panels and which have a core of mineral wool or insulating foam (Figs. 9 and 10).

Roof beam according to claim 4, characterized in that said prefabricated units are made of box-shaped units, the opposite outer and transverse sides of which consist of fiber-reinforced building plate or composite plate, and which has a core of mineral wool or insulating foam, which furthermore is provided with upper and lower metal plates spaced apart (Fig. f. 12).

Roof beam according to claim f, characterized in that said connecting plates are made of metal or low heat conductivity (U-value) composite plates arranged to be connected to opposite vertical insides of said upper and lower U-shaped metal profiles. , and comprising an integral transverse connecting shot integrated with the connecting plates.

Prefabricated roof panel element comprising one or more longitudinal roof beams according to claim 1, said roof beams being located along opposite sides and between said opposite sides of the roof panel element, characterized in that it comprises an upper connection between said longitudinal roof beams, which consists of a building plate of inorganic and non-combustible material, a trapezoidal profiled steel plate or sandwich panel, a layer of pressure-resistant insulation, an upper roof membrane as well as a sub-liner of inserts and insulation boards.

Prefabricated roofing sheet element according to Claim 9, characterized in that the undercoat consists of steel, light metal or inorganic and non-combustible building boards.