EP3023556A1 - Fire barrier element and fire barrier formed from fire barrier elements - Google Patents

Abstract

The invention relates to a Brandriegeleleinent with a facade side attachable first side (also called facade side), wherein the first side has an average orientation, which is a rectified two-dimensional plane assignable, a second side (also called front), with an upper and a lower end wherein the second side extends from the lower end to the upper end, wherein the side facing the front side of the second side and / or the entire second side facing away from the facade side, facing the upper end and adjacent to the lower end lower third side (also called the bottom), one at the upper end facade side adjacent deletion or depression with a front bounding inner wall, wherein the inner wall is bounded above by the upper end of the front, the front side at least in sections a continuous and / ode r has stepped decreasing distance to the two-dimensional plane towards the upper end, said distance being determined orthogonally from the two-dimensional plane. Furthermore, the invention relates to fire bars, composite thermal insulation system and building facades, which include said fire bolt elements, Also, the invention relates to the use of such fire bolt elements as a fire barrier.

Description

The present invention relates to a fire bolt element and a fire bar, comprising at least two, in particular a plurality of inventive fire bolt elements, as well as the use of the invention Brandriegelelements or the fire bar as a fire barrier in external thermal insulation systems for building facades and to connect or obstruct a cross-floor fire forwarding in the insulation layer of EIFS. Furthermore, the invention relates to thermal insulation composite systems comprising at least one such inventive fire lock element or a fire bar and building facades comprising at least one inventive fire lock element or at least one inventive fire bars or at least one inventive thermal insulation system.

Thermal insulation systems, for example based on foamed styrene polymers, when installed on building walls, in case of fire, in comparison with non-insulated building walls, do not regularly increase the risk of increased fire propagation. This is partly due to the fact that thermal insulation systems are usually provided immediately after installation on the building wall with a mineral plaster layer, not least this also to avoid bowl formation by sunlight when using graphite or soot-containing Styrolpolymerisatdämmsysteme.

In Germany, flame-retardant EPS rigid foams are regularly used in construction for thermal insulation. These begin to soften and shrink slowly at temperatures above 100 ° C. Only with further warming does the melting process begin. From the melt can be at prolonged heat develop gaseous, combustible decomposition products. These can form flammable gases under fire conditions at temperatures above 350 ° C. Without a source of ignition, these thermal decomposition products ignite only at temperatures in the range of 450 ° C to 500 ° C. Up to these temperatures, EPS foam is not self-igniting, and it does not cause smoldering fire. As soon as the contact with an extraneous flame, a so-called primary fire, is interrupted, generally no further burning or afterburning or afterglow is observed when the EPS rigid foam contains the customary flame retardants. Accordingly, in Germany, EPS rigid foam equipped with conventional flame retardants is a product that has been classified by the DIBt as having low flammability (B1 according to DIN 4102). It has also been shown that fire and carbonization gases, which emanate from EPS rigid foams, are less dangerous than the thermal decomposition products of cellulosic building materials such as wood fiber boards or cork.

Structural fire protection measures are required in particular for external thermal insulation systems with insulation thicknesses greater than 100 mm in order to prevent the facade system from contributing to fire propagation through the façade. Here, for example, Stcinwollestreifen over lintels or so-called fire bars are used. Such fire bars may e.g. be formed of mineral wool or polyurethane.

In a fire bar, also called fire protection bar, it is usually a substantially complete horizontal interruption of the foam insulation preferably in at least every other floor of a material that prevents or prevents the spread of fire. Especially with façade fires, a fire bar prevents the formation of a chimney. Thus, a fire bar must withstand at least for a certain time a fire or fire. Fire bars are therefore usually made of non-combustible materials which have a sufficient height to prevent the spread of fire. Even material that breaks quickly in case of fire is usually unsuitable.

Conventional fire bars are cuboidal products that are matched in their external dimensions to the thermal insulation composite system in which they are to be integrated. A generic fire bar would be, for example, a 200 mm high solidified mineral wool strip with a melting point> 1000 ° C. The components are usually installed in the form of a fire-retardant liner between the insulation boards. Accordingly, the foamed insulation material rests on the upper side of the rectangular fire bar, so that it does not come to form a thermal bridge.

The approved compositions and dimensions of fire bars are subject to the building regulations of the respective countries, so that the expert usually takes these into account when designing a new fire bar.

For ventilated thermally insulated building facades beats the EP 731 685 A2 the use of a firestop in combination with a flame arrester of non-combustible material extending horizontally substantially over the entire width of the vent gap. It is preferable to use polyurethane foam materials for the fire barrier and a support structure of a metallic or ceramic profile material for the flame barrier element. In the manner described should be avoided that the ventilation gap acts like a fireplace in case of fire.

In the DE 20 2007 007 225 U1 a component for a thermal insulation composite system is described, on the one hand get the problem of fire propagation under control and on the other hand, an inhomogeneity in the material characteristics in the facade surface should be avoided. This is achieved by arranging a fire protection layer of, for example, mineral wool, glass fabric, needle felt, a coated glass mesh or mortar between two foamed insulation elements, this fire protection layer has to extend over the entire cross-sectional area of the device. In this way, one would obtain a cuboid structure, which should be easy to integrate into conventional thermal insulation systems.

From the DE 10 2007 034 112 A1 is a fire protection element with a provided with Intumeszenzmasse protection means carrier, in which at least transversely to a longitudinal extent strength conferring foam rope is added in a formed by a fabric or by a nonwoven wrapping. At least part of this sheath or the foam part are used here as a protective agent carrier. By this fire protection element is a more advantageous continuous Get fire bars. However, a special arrangement of the bonded pieces of fabric is needed to ensure a perfect connection with the facade.

The AT 506 103 B1 deals with a fire barrier made of fire-resistant or fire-resistant material based on expanded polystyrene particles. Here, the polystyrene granulate particles or beads are to be coated at least over partial areas of their surface with at least one fire or fire propagation inhibiting or refractory silicate. A Brandriegel made of it should be easy to install while ensuring adequate thermal insulation.

From the DE 20 2008 001 750 U1 is a cuboid fire barrier consisting of PUR or PIR hard foam out, which has a homogeneous cell structure over its entire thickness and at the same time free of cover layers. For example, from glass / mineral fleece, adhesive layers or fasteners to be. In addition, there should be an optimal edge dynamic rigidity in this fire barrier. Such a fire barrier should be particularly easy to manufacture and deliver in exactly the same thickness as the intended for each construction projects Polystyroldämmstoffplatten.

The DE 10 2009 040 203 A1 describes a molded foam element of polyurethane foam or Polyisocyanuratschaum for thermal insulation composite systems on buildings with a cell structure having in at least two mutually perpendicular spatial directions distinguishable geometry structures.

The EP 2 604 763 A1 is concerned with a fire bar, which is connected to a spacer which extends with a rear gap gap bridging portion between an outside of the fire bar and the inside of the facade cladding. This fire bar has to be made of an elastically deformable material. In this way, a building facade should be obtained with a simple, easy to assemble construction.

The DE 10 2012 001 613 A1 relates to a thermal insulation composite system in which the fire barrier is formed from plate-shaped or profile-shaped thermal insulation elements, which airgel particles and at least one water-based inorganic and / or have organic binder and have a thermal conductivity less than or equal to 0.028 W / (mk). In this thermal insulation composite system, the fire barrier should be flexible and can be integrated, for example, in a lintel or soffit area of an opening in a building exterior wall.

The DE 20 2012 100 418 U1 discloses a one-piece fire-barrier made of fibrous material which extends over the surface of an insulating layer in the direction of the facade cladding and which has a compressibility and / or flexibility oriented at least predominantly between the building wall and facade cladding. This fire bar is to allow a simple and inexpensive equipment of building facades with thermal insulation elements without additional structural elements are provided.

In the DE 20 2007 007 225 U1 describes a thin fire-resistant layer, which is incorporated in an insulating element of polystyrene. Said layer may be designed, for example, 1 mm thin and channel-shaped. An advantage of the fire protection layer should be the avoidance of discoloration of Fassadcnputzes, which usually occurs in Brandricgeln.

The DE 196 43 618 A1 also discloses a thin fire protective layer of fabric impregnated with a flame retardant. This should foam and harden in the event of a fire. Here too, the use of a fire protection layer, instead of a firestop, avoids a façade discoloration.

Conventional fire bars are often afflicted with the disadvantage that during a fire of a still unplastered facade liquefying burning material of a thermal insulation facade collects on the fire bar and maintains the fire there or reignited. Nor is it ensured that burning material is kept away from the remaining facade.

The present invention therefore an object of the invention to minimize or completely eliminate the above-mentioned disadvantages of conventional fire bars and fire bar elements. In particular, the contact between falling burning material and dripping liquefying material of the facade be reduced or minimized. Also, the direct or indirect transfer of energy, in particular thermal energy, between said falling burning and dripping liquefied materials and by a fire below the fire bar should be reduced. In particular, so Brandriegelelemente or fire bars should be made available with which a fire retransmission can be effectively prevented.

The object underlying the invention is achieved by a fire-locking element with a facade side attachable first side (also called facade side), wherein the first side has a central orientation, which is a rectified two-dimensional plane can be assigned, a second side (also called front), with a upper and a lower end, wherein the second side extends from the lower end to the upper end, wherein the façade side opposite portion of the second side and / or the entire second side facing away from the facade side, facing the upper end and adjoining the lower end of the lower third side (also called the bottom), an adjoining the upper end facade side of the omission or depression with a front delimiting inner wall, wherein the inner wall is bounded above by the upper end of the front, characterized in that the front side has a continuously and / or gradually decreasing distance to the two-dimensional plane in the direction of the upper end, said distance is determined orthogonally from the two-dimensional plane. The inventive fire bar system has a structure that allows the discharge of burning materials and at the same time has a catchment system for liquefying parts of a thermal insulation facade.

For the purposes of the present invention, the two-dimensional plane is to be understood to mean an infinitely extended plane which is rectified with the middle orientation of the facade side. The said two-dimensional plane is a mathematical auxiliary construct in order to be able to describe the structure of the firing bolt precisely, that is to say in the form of a mathematical auxiliary construct. an infinitely extended two-dimensional plane as a concrete physical object is not part of the inventive fire bar.

Under the facade side of the invention Brandriegelelements that page or surface of the fire bolt element is to be understood that in a building wall mounted state of the fire bar facing the building wall and on the generally takes place, for example by means of bonding or with dowels, the connection to the building wall. In the context of the invention, a building wall is to be understood in this context as a building wall or wall not provided with an insulating material. Preferably, the surface of the building wall, on which the fire bar or the fire lock elements are attached, partially or completely from a solid mineral substrate. Preferably, the building wall side is apart from surface structures substantially flat or only slightly curved. The building wall is to be distinguished from the building facade according to the invention, the latter generally additionally comprising the external thermal insulation composite system together with fire barrier elements. Fassadcnseitig means in the sense of the present invention in the direction of the building wall with generic use of the fire lock element.

The front of the fire bolt element, however, at least partially faces the visible side in generic use. On the side facing the visible side, it can preferably be provided with a coating, for example a plaster layer, together with the external thermal insulation composite system into which the fire barrier element is integrated. In principle, the inventive fire-retardant element can be partially or completely coated. In an advantageous embodiment, the inventive fire-barrier element is coated at the locations which are exposed to flames or radiant heat in the event of a fire. Such a coating may be single or multi-layered. In a variant embodiment, this coating of the inventive fire-retardant element helps to prevent it from being heated or at least temporarily to delay it. For example, it is possible to resort to mineral and / or organic coatings. These coatings may contain flame retardants and / or intumescent constituents or are already fire retardant as such. It is also possible that these coatings, even on the basis of their heat capacity alone, contain the desired reduced heating of the inventive fire-retardant element.

The front is bounded up and down by the top and bottom of the front. The upper end is in generic use, the highest point of the front and the front inner wall. The upper end, especially if the Facade-side inner wall is not higher, preferably also the highest point of the fire bolt element. Under the underside of the invention Brandriegelelements shall be understood in the context of the invention, that surface or side, which faces in conventional horizontal attachment of the fire bolt element of the lower bearing surface of the fire in the thermal insulation composite system or represents this. It is limited in its dimensions by the lower end of the front side and by the adjoining façade side laterally. Preferably, the underside is substantially flat and, when used in general, has a substantially horizontal average orientation, wherein the substantially flat underside may nevertheless be structured. The designation of the boundary surfaces of the inventive fire-barrier element with facade side, front side and underside generally does not exclude that these surfaces or sides themselves may or may not be structured in themselves.

According to the invention, a recess in the form of a depression or omission joins the upper end of the front side in the direction of extension to the facade side or the two-dimensional plane. Recess is the generic term for omission and depression in the present document. For the purposes of the present invention, an omission is to be understood as meaning a recess which has no facade-side inner wall. For the purposes of the present invention, the recess, in particular trough-shaped depression, should differ from the described deletion in that the corresponding recess has a facade-side inner wall.

The front inner wall of the recess or omission extends to the lowest point of the recess. Preferably, in the case of the depression, the façade-side inner wall or, in the case of omission, the façade side or, in the case of recessing as well as omission, adjoins this front-side inner wall, if appropriate, in particular essentially horizontal, collecting tray. Horizontal in the sense of the present invention is orthogonal to the two-dimensional plane. For the purposes of the present invention, essentially horizontal means that the mean orientation is not more than 10 °. preferably not more than 5 °, deviates from the orientation orthogonal to the two-dimensional plane. At the, in particular substantially horizontal, collecting tray can in the case of depression, a facade-side inner wall or in the Case of omission connect the facade side. In one embodiment, the inner wall is at least partially substantially vertical. Vertical means in the sense of the present invention parallel to the two-dimensional plane. For the purposes of the present invention, essentially vertical means that the average orientation does not deviate more than 10 °, preferably not more than 5 °, from the orientation of the two-dimensional plane. The above definitions of vertical, substantially vertical, horizontal and substantially horizontal are the basis of the entire publication.

The front-side inner wall preferably extends from the upper end to a substantially horizontal collecting base or to the façade side or to the inner side of the façade, the inner wall having an average height of at least 5 cm. preferably at least 10 cm and more preferably at least 15 cm.

The recess as well as the omission can thus have different cross-sectional shapes. For example, the cross-sectional shape of the recess may be V-shaped, square, rectangular, trapezoidal (i.e., undercut), circular cut, or otherwise configured in cross-section. The omission may be L-shaped, for example. But other variants for the omission are conceivable, with preferred embodiments can be derived from the wells described above, by the facade side inner wall is removed.

According to one embodiment, the fire bar element is circumscribed by the facade side, front and bottom and by the recess or omission, wherein the depression or omission of the upper end of the front side adjoins the facade and is bounded on the other side by the facade side. This does not exclude that the depression or omission on one side or possibly also on both sides may comprise a more or less wide edge region and / or collecting base.

It is advantageous if the depression or omission is separated by a collecting bottom layer from the bottom, wherein said layer is preferably at any point thinner than 1 cm, in particular 5 cm, and most preferably at any point thinner than 10 cm. Due to the sufficient thickness of the material layer in combination with the preferably low thermal conductivity of the material of the fire bolt element is a good insulation against fire located under the fire element or fire guaranteed. Preferably, said material layer does not differ substantially in composition from the remaining material of the firestar.

A height difference between two points is to be distinguished from the distance between two points, if the two points are not arranged vertically one above the other. In the sense of the present description, the height is determined in each case in a cross-section, orthogonal to the two-dimensional plane, of the fire bolt element or of the firestar, parallel to the two-dimensional plane (vertical). If the height or the corresponding height difference is used, for example, between the upper and the lower end of the front, this always means the mean height or height difference over the entire length of the fire lock element. Distances between predominantly or entirely substantially horizontal surfaces are also measured vertically. Distances between predominantly or entirely substantially vertical surfaces, however, are determined horizontally. The mean distance means in particular the average distance over the entire length of the fire-locking element. Analogously, other average measures are to be treated in particular. Preferably, the fire bolt elements according to the invention are designed substantially uniform over their entire length, so that, for example, the local height or height difference of a cross section corresponds approximately to the mean height or height difference over the entire length.

By graduated decreasing distance to the two-dimensional plane is to be understood a stepped structure in which the distance to the two-dimensional plane in the direction of the upper end of the front side gradually decreases. In this case, for example, two angularly, in particular orthogonally, mutually arranged surfaces form a stepped structure only if at least one of these surfaces is adjoined by a third surface discontinuously at an angle, for example a third surface with a generic use of a substantially horizontal or substantially vertical tilt. Thus, for a stepped structure according to the invention at least three discontinuously connected surfaces are necessary. Preferably, a stepped structure comprises at least three surfaces, which are preferably connected at an angle of 30 ° to 175 °. Also, according to the invention stepped structure with deformed, ie not flat surfaces possible. Stepped structures can, for example, by discontinuous transitions between arched surfaces are formed. Also, if the transition between the surfaces is continuous, it is usually a continuously decreasing distance, as described below. However, mixed forms with continuous and discontinuous transitions are also provided according to the invention.

For the purposes of the invention, at least two stages, each formed of two surfaces, are preferably required for a stepped structure. Stages in the context of the present invention are formed by two discontinuously connected surfaces, wherein different interconnected stages are also connected discontinuously. Each step is in a, preferably in generic use substantially vertical. Stepped paragraph and a, preferably in generic use substantially horizontal, stepped essay subdivided. A typical example of steps are stairs. In this case, for example, the stepped shoulder or stepped attachment of a first stage can have the upper end of the front side, while a second stage adjoins this first stage. Said steps may in a preferred embodiment be composed of alternately substantially horizontal and substantially vertical surfaces. Instead of an orthogonal angle, acute and obtuse angles are also suitable for forming stepped structures or steps. In an expedient embodiment, it is therefore provided that the front side has a graduated decreasing distance in at least one first section, wherein at least one, in particular essentially horizontal, step attachment or one, in particular substantially vertical, stepped shoulder and / or a stepped structure up to the extends the upper end.

Accordingly, in one embodiment of the invention, from the upper end of the front side first a stepped shoulder, then a step attachment and finally subsequently a stepped shoulder extend. Alternatively, it is possible that from the upper end of the front only a step attachment then a step paragraph and finally then a step attachment extends.

By the front side between the upper end and lower end at least partially having a stepped structure, molten and / or combustible material which falls from the front of the upper end of the front of the invention fire bar or the fire lock element according to the invention and in this case not in the Deepening or omission passes away from the facade. In this case, particularly preferred are also stepped structures which on average describe the inclination of a surface.

A continuously decreasing distance to the two-dimensional plane towards the upper end of the front fulfills a similar function. Here, the material is kept away from the depression or omission. Embodiments which have both stepped and continuous sections are also preferred. For example, the fire bolt element at the top of a first stage, to which a second stage connects, which has a more or less inclined surface instead of a horizontal surface. Particularly preferred embodiments are those in which said continuously decreasing upward distance adjoins the upper end of the front side, wherein the continuously increasing the upward decreasing distance associated surface preferably has a substantially concave or convex curvature or is flat. As a result, falling, burning material is particularly effectively led away from the depression or omission.

Embodiments which, when used in general, have substantially vertical subsections of the front side, are preferred. Also suitable are embodiments in which, in general use, the front side has at least one section with a gradient of 3 to 90%, preferably 5 to 60% and in particular 10 to 50%. Proper inclination ensures that the material drains off. Flat inclinations ensure that an area is provided on which falling material can hit.

In a preferred embodiment extends from the upper end of the front side, a first portion of the front, with a continuously increasing distance to the two-dimensional plane towards the lower end of the front, to an edge, from which a second, preferably in generic use substantially vertically extending portion of the front extends in the direction, preferably to the lower end of the front side. Preferably, the edge is substantially straight and / or the second portion of the front side substantially flat. Said second section may be provided with plaster and / or another coating or paint layer, such as a fire-resistant paint layer.

In a further particularly preferred embodiment, the stepped structure is formed by at least a portion of a delimiting strip. Such a boundary strip in the form of an obstacle prevents particularly effective way that burning material overcomes the upper end of the front and falls into the depression. Preferably, the boundary strip is made of another, in particular thermally conductive, material than the remaining material of the fire-locking element.

Usually, a boundary strip has a longitudinal extent (strip length) in the direction of the longitudinal extent of the fire bar element and a strip height and a strip thickness, wherein the average strip thickness is preferably smaller than the mean strip height of the fire bar, in particular at least three times smaller. The average strip length preferably corresponds to the average length of the fire bar element. Preferably, the average strip thickness of the delimiting strip at the upper end of the froncites is greater than 0.1 cm, in particular greater than 0.2 cm and particularly preferably greater than 0.3 cm. In a preferred embodiment, the average strip thickness of the delimiting strip is less than 2 cm, preferably less than 1.5 cm and particularly preferably less than 1.0 cm and / or the mean strip height is greater than 2 cm, preferably greater than 6 cm and particularly preferably greater than 10 cm. Preferably, the boundary strip has a constant strip thickness over the entire strip length and in particular also the strip thickness. The dimensions of the boundary strip on the one hand cause heat in the event of fire is well dissipated and the boundary strip is stable for a sufficient period of time and on the other hand, that the material consumption of the often expensive heat conductor is not too high and the insulation of the thermal insulation facade is not reduced too much. Due to said strip thickness, the boundary strip in corresponding embodiments can also form a first step in the sense of the invention.

In a preferred embodiment, the boundary strip tapers in the direction of the upper end of the front side. It is conceivable that the boundary strip does not form a step, but only has a continuously decreasing in the direction of the upper end of the front side distance according to the invention. An upwardly tapering boundary strip is advantageous because no burning material comes to rest on the boundary strip.

The boundary strip can be connected to the rest of the material of the fire-locking element by being attached, in particular by gluing, fixed on the remaining material or poured into the material of the fire-locking element.

Preferably, a partial section of the delimiting strip is free on the front and on the facade side, wherein the partial section exposed on both sides preferably has a height of at least 1 cm, preferably at least 2 cm, particularly preferably 4 cm and in further expedient embodiments also at least 8 cm. Here, the upper end of the front is part of the boundary strip and separates the exposed facade side surface of the delimiting strip, which is attributable to the inner wall, from the opposite, exposed surface of the delimiting strip, which is attributable to the front. The exposed part ensures a barrier between the front and the recess or omission. On the one hand, the dimensions of the delimiting strip cause heat to be well dissipated in case of fire and, on the other hand, the material consumption of the often expensive heat conductor is not too high and the insulation of the thermal insulation facade is not reduced too much.

Said material of the boundary strip, which preferably does not correspond to the remaining material of the fire bar, is preferably a thermally conductive material, in particular more thermally conductive than the material of the fire bar element. The thermal conductivity of the delimiting strip is preferably greater than 0.1 W / (m * K), in particular greater than 2 W / (m * K) and particularly preferably greater than 5 W / (m * K). Heat conductors with a thermal conductivity of more than 15 W / (m * K) or 25 W / (m * K) are very particularly preferred.

Preferably, the materials used or material mixtures of the fire bar are not flammable according to DIN EN 13543-1. The regularly low thermal conductivity prevents the fire bar from disproportionately affecting the efficiency of the rest of the thermal insulation facade. Also, in case of fire, the depression or omission is better isolated.

Preferably, the materials used or material mixtures of the fire bar - apart from the boundary strip - only to a small extent thermally conductive.

More preferably, said thermal conductivity is in the range of 0.001 to 0.3 W / (m * K) and preferably in the range of 0.005 to 0.15 W / (m * K). The low thermal conductivity prevents the fire bar from disproportionately affecting the efficiency of the rest of the thermal insulation facade.

Preferably, the fire locking element is at least partially, in particular predominantly or completely, made of a material which is non-combustible, non-melting and dimensionally stable at 550 ° C. preferably 800 ° C and especially preferably 1000 ° C. Preferably, the fire barrier element is dimensionally stable even at room temperature (i.e., 25 ° C).

Preferably, the fire barrier element itself comprises - apart from the boundary strip - at least partially, preferably predominantly or completely, a material which is selected from the group consisting of mineral wool, in particular in the form of mineral wool lamella strips or mineral wool strip, Duroplasartart, especially rigid polyurethane foam (PUR foam), rigid polyisocyanurate foam (PIR foam) and / or phenolic rigid foam (PF foam), mineral foam, in particular water glass, phosphate-bonded, autoclave-hardened, hydraulically curing and / or hydratically curing mineral foam. Composites of silicates and foamed styrene polymers or mixtures thereof. Said material preferably has usually a low thermal conductivity and also a very low flammability.

The average orientation of the boundary strip is preferably substantially vertical in generic usage. In a further preferred embodiment, the average orientation of the delimiting strip does not deviate more than 45 °, preferably not more than 25 °, from the orientation of the two-dimensional plane.

The boundary strip may be formed in an expedient embodiment as an extension of the inner wall, for example, in one piece or as a separate component, for example, attached directly to this inner wall. Furthermore, the boundary strip can be mounted as a separate element also spaced from the inner wall in the direction of the front side, for example at a distance of more than 0.3 mm. Suitable distances are for example in the range of 0.5 to 3 cm.

The thermal conductivity of the boundary strip effectively dissipates energy. As a result, burning material coming in contact with the boundary strip is cooled down. In addition, high local temperatures are avoided on the inner wall of the omission or depression. Both regularly prevent in a particularly efficient way that the material can ignite within the depression or the omission. If, however, inflammation does occur in isolated cases, a controlled burn-off takes place at most, which is itself not suitable for contributing to a further spread of the fire. The boundary strip also impedes the oxygen supply in the omission or depression, which additionally makes inflammation and / or the emergence of an uncontrolled fire more difficult.

According to the invention, a wall region exists between the inner wall and the front side, said wall region preferably tapering in the direction of the upper end of the front side. As a result, burning material can be particularly effectively removed by gravity, without it rests in the region of the upper end.

In the inventive fire-retardant element, it has proved to be particularly favorable if the mean distance between the inner wall and the opposite section of the front side, in particular in the upper region, is 5 to 80%, preferably 10 to 70% and particularly preferably 20 to 60% of the mean distance of said portion of the front to the two-dimensional plane, the mean distances being determined orthogonal to the two-dimensional plane. By the above measure is ensured in a particularly advantageous manner that the depression or the omission have a sufficient width to accommodate the liquid facade material can. Preferably, the mean distance of the inner wall from the two-dimensional plane is at least 5 cm, in particular at least 7 cm and particularly preferably at least 8 cm. The average distance of the inner wall from the opposite section of the front side is preferably at least 5 cm, in particular at least 8 cm and very particularly preferably at least 10 cm.

Further, it is preferable that the average distance of the upper end of the front side to the two-dimensional plane is 10% to 90%, preferably 20% to 80% and particularly preferably at least 30 to 70% of the mean distance of the lower end of the front side to the two-dimensional plane the distances orthogonal to two-dimensional level can be determined. The mean distance of the upper end is preferably at least 5 cm, in particular at least 7 cm and particularly preferably at least 9 cm from the two-dimensional plane. As a result, on the one hand, enough space is ensured from the upper end of the front side to the facade, so that the opening area of the recess is sufficiently wide. On the other hand, it is advantageous if the upper end of the front side is closer to the facade than the lower end of the front side. This increases the design options in the formation of the continuously and / or gradually decreasing distance.

Furthermore, it is advantageous if the maximum depth of the omission or depression, i. the mean height difference between the upper end of the front and the lowest point of the omission or depression. 10 to 90%, preferably 15 to 80% and particularly preferably 20 to 70% of the mean height difference between the lower and upper end of the front side and / or that the average distance between the upper end and lower end of the front side is greater than the average distance of upper end to the maximum of this remote area of the omission or depression. The maximum depth or minimum height of the omission or depression is preferably at least 5 cm, in particular at least 10 cm and especially preferably at least 15 cm.

For the purposes of the present invention, the maximum horizontal distance between the facade side and the two-dimensional plane, the thickness of the fire bolt element and the height difference between the uppermost point of the fire bolt element, in particular the upper end of the front side and the lowest point of the bottom reflect the height of the fire bolt element, the latter being determined vertically as described above. The heights and thicknesses of a cross section of the fire bolt element thus correspond to the maximum extent parallel or orthogonal to the two-dimensional plane. Preferably, the height is greater than the thickness. The height may, for example, be in the range of 10 to 60 cm or 20 to 50 cm, in particular if the thickness of the firestop is in the range of 20 to 60 cm, for example about 20 cm. Here, the thickness of the fire bars correspond regularly with the thickness of the insulating layers, which are separated from the fire bars within an insulated facade.

The length of the fire bolt element according to the invention. i.e. the distance of the opposite side walls of the same, between which extend the bottom, the facade and the front side may be greater than, equal to or less than the height or the thickness of the fire bolt element. It has proven to be expedient to resort to such inventive fire lock elements, in which the length of this fire lock element is greater, in particular by a multiple greater than the thickness or in particular height of the same. Usually, the length of easily manageable fire bar elements in the range of 0.4 m to 1.2 m. Preferably, the recess or omission extends over the entire length of the fire bolt element. This has the advantage that over the entire length of the spread of a fire is effectively prevented.

In one embodiment, the front side is aligned substantially vertically in a partial region, preferably in a lower partial region, which comprises at least 5%, preferably 25% and in particular preferably at least 50%, and / or the underside represents at least sections, preferably completely, a substantially planar surface which is substantially horizontally aligned. This is advantageous. Said underside can be inserted so better in the facade. It is also conceivable to use the said area for applying a plaster.

According to the invention, the depression has a facade-side inner wall. In addition, the recess in the generic use of the fire bar preferably front side can be limited, if the inner wall has a lower height than the upper end of the front. In principle, the inner wall according to the invention can be higher than, lower than or equal to the upper end of the front side. The latter two variants represent preferred embodiments. The omission is preferably limited in the generic use of the firestop on the facade side by a building wall.

By the above measures, a groove is formed along the longitudinal side of the fire bar, which is suitable and designed for collecting molten facade material. In a recess with an inner wall, the facade side is increased, so that a better fixation of the bolt in case of fire is possible. At an omission or a depression with a low inner wall of the Reduced material consumption and used the low flammability of the facade without insulation to form said gutter.

In a suitable embodiment, the omission or depression is at least partially, in particular substantially completely, filled with at least one heat-shrinkable material, in particular with foamed styrene polymer. which preferably has a maximum heat conduction of 0.060 W / mK. Even if the depression or omission, unlike the fire barrier element itself, is filled with a heat-shrinkable material and the overall component thereby forms a square or rectangular cross-sectional area, there is still an omission or depression within the meaning of the invention. Because as soon as the fire occurs, the omission or depression is released and can thus fulfill their effect according to the invention. The above measures improve the insulation and still ensure that the omission or recess is available in case of fire. The stability of the facade insulation is also increased. It can be provided that rests on the heat-shrinkable material, a no or only flame-retardant layer, which has a greater thermal conductivity than the heat-shrinkable material.

If the depression or the omission is filled with a styrene polymer with pronounced heat shrinkage, a possible convection in the integrated in a composite thermal insulation system omission or depression can be prevented and the thermal insulation of the bolt can be further improved. If a primary firing takes place in front of the unpainted façade, this fitting piece shrinks and / or melts directly into the recess or depression, so that the desired catch basin automatically forms before and while molten foamed insulating materials such as styrene polymers are removed from the overlying insulating material or foam Polystyrene foam drips off.

By juxtaposing the fire bolt elements according to the invention flush over their respective side surfaces, one obtains a fire bar according to the invention, which is sometimes referred to as a rotating, preferably horizontally encircling, fire bars. In general, fire bars that extend along the length of a building, not cinstückig executed, but from a variety of individual Brandriegelelementen formed. Of course, such individual fire bolt elements can also be used, for example, to be mounted only above a building opening or a fall. Fire bar elements or fire bars which, preferably horizontally, are arranged in the region above falls, in particular door and / or window lintels, or above building openings, in particular door and / or window openings, are preferred. In such cases, for the sake of simplicity, one also regularly speaks of the presence of a bolt. Preferably, the inventive fire bar is a circulating fire bar. Although inventive fire bolt elements and Brandriegcl can also be installed at an angle, they are preferably installed substantially horizontally. Preferably, at least two inventive, in particular a plurality of inventive fire barrier elements, as described above, form a fire bar according to the invention.

The fire bar or the fire bar element are often heated by the fire from below. By applying a, in particular mineral, coating, a cooling effect can be achieved. By using such a coating, the height of the fire bar can be made smaller. This creates a greater freedom of design. Accordingly, it can be provided that the fire-locking element has a, in particular mineral or organic, coating, preferably on the front side and / or the top and / or the bottom and / or on a portion or the entire region of the depression or omission. It is particularly expedient here, at least a partial area or the entire area of the depression or omission and / or the underside with the said, preferably mineral. To provide coating.

Furthermore, the use of the above-described fire bars or fire bar elements is the subject of the present invention. Preferably, the arrangement, preferably horizontal arrangement, of at least one inventive fire lock element or at least one inventive fire bar in the area above falls, especially door and / or lintels, or above building openings, in particular door and / or window openings. Preferably, the inventive fire lock element or the fire lock according to the invention also provides a, in particular substantially continuous, interruption of a facade insulation comprising or consisting of foamed styrene polymers. Particular preference is also the use of the invention Brandriegelelements or the fire bar for obstructing or obstructing a cross-fire propagation in the insulating layer of thermal insulation systems comprising or consisting of foamed styrene polymers.

Furthermore, thermal insulation composite systems comprising insulating materials, in particular foamed or extruded styrene polymers or foamed polyurethanes, for a building facade and at least one inventive fire lock element or a fire bar according to the invention. Subject of the invention.

Building facades, comprising at least one inventive fire lock element or at least one inventive fire bars or the above-described thermal insulation composite system, are the subject of the invention. Preferably, the fire lock element or the fire bar thereby represent a horizontal fire barrier. Particularly preferred are building facades in which these comprise at least one building exterior wall and the fire bolt element or the fire bar on its facade side directly or indirectly to this building exterior wall by means of at least one mineral adhesive and / or organic adhesive , and / or by means of dowels or a rail construction is attached. Preferably, the fire bar is attached substantially continuously to the building.

The fire-blocking element according to the invention is based on the surprising finding that, in the event of fire, liquefied material of the facade usually runs down or drips or falls down very close to the facade. In contrast, burning material usually drips or drips away from the façade. Surprisingly, the inventive fire-blocking element can be selectively used to separate burning material from the material that runs down the facade. It is advantageous that, in particular despite the apparently uncontrollable conditions of a facade fire, a targeted separation of said burning and molten materials can be achieved. The molten material that drips from the facade is now no longer available as a fuel and is basically just as ineffective as a fire-resistant material that dissolves from the facade. The invention Fire barrier elements also prevent them from being supplied with a sufficient amount of energy in the form of heat energy. The molten material caught in it does not ignite anymore. Material that still burns enters the recess or omission of the invention Brandriegelelements extinguished there as a rule. The fire barrier element according to the invention ensures that the molten material trapped in the depression or extinction is no longer able to promote fire propagation. In this way, an essential part of the runaway or falling or dripping material can be withdrawn from the fire, so that the fire is less severe fuel shortage or completely extinguished. In particular, it is advantageous that the aforementioned structural changes compared to the known from the prior art fire bars cause a significant improvement in fire safety.

Figur 1 a) - g)

schematische Querschnittsansichten verschiedener Ausführungsformen eines der erfindungsgemäßen Brandriegelelemente;

Figur 2

perspektivische Ansicht eines erfindungsgemäßen Brandriegelelements gemäß Fig. 1 a):

Figur 3

perspektivische Ansichten eines longitudinalen Brandriegelelements;

Figur 4 a)

schematische Querschnittsansicht einer Ausführungsform einer erfindungsgemäßen Gebäudefassade mit einem Brandriegelelement gemäß Figur 3;

Figur 4 b)

schematische Querschnittsansicht einer Ausführungsform einer weiteren erfindungsgemäßen Gebäudefassade mit einem Begrenzungsstreifen;

Figur 5

eine schematische Querschnittsansicht einer erfindungsgemäßen Gebäudefassade gemäß einer weiteren Ausführungsform bei einem Fassadenbrand.

Further features and advantages of the invention will become apparent from the following description, are explained in the preferred embodiments of the invention by way of example with reference to schematic drawings. Showing:

FIG. 1 a) - g)

schematic cross-sectional views of various embodiments of a fire locking elements according to the invention;

FIG. 2

Perspective view of a fire lock element according to the invention Fig. 1 a) :

FIG. 3

perspective views of a longitudinal fire bolt element;

FIG. 4 a)

schematic cross-sectional view of an embodiment of a building facade according to the invention with a fire lock element according to FIG. 3 ;

FIG. 4 b)

schematic cross-sectional view of an embodiment of another building facade according to the invention with a boundary strip;

FIG. 5

a schematic cross-sectional view of a building facade according to the invention according to a further embodiment of a facade fire.

FIGS. 1a) to g) show various variants of the invention Brandriegelelemente, with a facade side 1 (first side), a front side 2 (second side), a bottom 3 (third side) and a surface of the recess or omission 4. The front side 2 is through the upper end 5 and the lower end 6 limited. At the upper end 5 of the front side 2, the inner wall 11 of a recess 9 connects in the form of a depression or omission. The facade side 1 can be a rectified two-dimensional plane 8 assign. In addition, a horizontal collecting tray 7 is shown. Although all embodiments have a collecting tray 7, it should be noted that, for example, semicircular or V-shaped depressions are also the subject of the invention. Said wall between the inner wall 11 and the front side 2 tapers in the direction of the upper end 5 of the front side 2 in all embodiments.

FIGS. 1a) to 1c) show embodiments without gradations in the context of the present invention with an upper portion in which a continuously decreasing distance to the two-dimensional plane 8 in the direction of the upper end 5 of the front side 2 is observed. FIGS. 1a) and d) each represent a recess 9 in the form of an omission, while FIGS. 1 b) and 1 c) such as e) to g) each show a recess 9 in the form of a depression. While Figure 1 a) and 1b) on the front side in each case comprises an edge and a continuously decreasing distance to plane 8 in the direction of the upper end 2, the transition to the vertical section is at FIG. 1c) continuous throughout. FIG. 1 d) also has front-side portions with continuously decreasing distances to the two-dimensional plane 8 in the direction of the upper end 5 of the front side 2, wherein the front side 2 is additionally stepped. FIG. 1 e) does not have a continuously decreasing distance to the two-dimensional plane 8 in the direction of the upper end 5 of the front side 2. The distance decreases gradually, wherein the upper end 5 is part of the boundary strip 13 and this limited upwards. The protruding over the surrounding material portion of the delimiter strip 13 can also be understood as a stepped paragraph, which is followed by the horizontal portion of the front as a step attachment. Since the boundary strip 13 projects beyond the surrounding material on both sides, ie on the front side and on the facade side, thus forming a barrier, this also becomes the case Prevents burning material from penetrating into the depression. FIG. 1 f) shows a boundary strip 13 to which a surface with a continuously increasing distance from the two-dimensional plane in the direction of the lower end 6 of the front side 2 connects. The front area of the limiting strip 13 and its upper edge together with said surface form the front side 2, which ends with the upper end 5. Also in the case of FIG. 1 e) the front 2 is partially formed by the boundary strip 13. FIG. 1 g) shows a modification of the inventive fire lock element according to FIG. 1 e) in that the boundary strip 13 is not formed in the sense of an immediate extension of the inner migration 11, but offset and further away from the facade side in the horizontal surface of the front wall in the illustrated embodiment is partially embedded. This can be done, for example, by inserting the boundary strip into the material of the front wall. Alternatively, there may be a groove in the front wall, in which the boundary strip is fitted in parts and glued, for example. It is also possible (not shown) to make the boundary strip angular, so that it flies in parts on the facade side facing the front surface of the front wall and preferably rests with another, unwound portion of the inner turning. These sections may be glued to the front wall, for example.

FIG. 2 shows the cross section of a firing bar of thickness B and the height H. For clarity, the elements and surfaces of the firestop were not quantified. Regarding the numbering of elements and areas be on FIG. 1 a) referring to the same embodiment. The lower end 6 of the front side 2 has a distance A1 from the upper end 5 of the front side 2 and a horizontal distance A3 from the two-dimensional plane 8. The inner wall 11 of the recess 9 in the form of an omission has a distance A6 from the front side 2, wherein the average distance between the inner wall 11 and the opposite portion of the front side 2 is slightly less, since it is determined over the entire length A7 of the inner wall 11 and this tapers in the direction of the upper end 5. The upper end 5 of the front side 2 has a distance A4 from the two-dimensional plane 8. The mean distance A1 between the upper end 5 and lower end 6 of the front side 2 is greater than the average distance A2 of the upper end 5 of the front side 2 to the maximum of this remote area of omission or depression. The average distance A4 of the upper end 5 of the front 2 to the two-dimensional plane 8 in the present case is about 55% of the average distance A3 of the lower end 6 of the front side 2 to the two-dimensional plane 8. The maximum depth A7 (in this particular embodiment also the length of the inner wall) of the omission, ie the average height difference between upper End 5 of the front 2 and the lowest point of the omission or depression, in the exemplary embodiment about 75% of the average height difference (A7 + A8) between the lower and upper end 5 of the front page 2.

FIG. 3 shows the perspective views of a longitudinal fire lock element. In this case, in contrast to the cross sections shown above, the length L can be recognized. Although this is not immediately apparent due to the perspective distortion, in the present case the length L is twice as large as the height of the firing bar. The thickness is about half the height. The numbering was analogous to the preceding figures.

FIG. 4 a) shows the schematic cross-sectional view of an embodiment of a building facade 17 according to the invention with a fire lock element 14 according to FIG. 3 , To said material is followed by the insulation or thermal insulation system 15, for example made of EPS rigid foam panels, a thermal insulation facade. These can, as well as the fire bar element 14 according to the invention, are connected by means of an adhesive 18 to the building wall 16. This may be a mineral adhesive. In order to avoid chimney effects, the building wall side of the fire bolt element according to the invention is connected to the building wall 16 over its entire area with the aid of the adhesive 18. Furthermore, the foamed insulation material directly adjoins both the underside 3 and a partial region of the front side 2 in order to avoid thermal bridges. In the recess 9 in the form of an omission is a heat-shrinkable material, in particular foamed styrene polymer containing.

FIG. 4 b) shows the schematic cross-sectional view of an embodiment of a building facade according to the invention 17 with a fire lock element 14. which has a boundary strip 13. The boundary strip is incorporated into the insulating material or thermal insulation composite system. The boundary strip 13 prevents material that falls on the front side 2, in the recess 9 in the form of an omission arrives. The second stage is formed by the remaining material of the fire bolt element.

FIG. 5 shows a building facade 17 in case of fire. The thermal insulation material melted by the fire, which was located above the fire barrier element 14 according to the invention, is dropped in molten form either along the path 20 on the facade into the recess 9 in the form of an omission, so that it forms a cooling melt 19, or to a lesser extent, passes over the path 21 on an inclined portion of the front side 2. The material dripped into the recess 9 in the form of an omission is protected from a primary fire, which originates, for example, from a building opening present below the fire bolt element 14 according to the invention. Due to the inclination of the upper portion of the front side 2, the burning material is led away on the way 20 of the omission. In particular, burning, if necessary, molten material is not conducted via the upper end 5 into the outlet, so that the molten material 19 advantageously does not ignite or at best a controlled burning takes place. Also, the height of the upper end 5 makes it difficult to supply oxygen to the region of the melt 19. The inner wall 11 prevents the molten material of the recess 9 escapes and forms together with the opposite wall 16 a groove. Also, the fire bar element 14 prevents heat input in the direction of the melt 19 present on the collecting tray 7. Although the term melt is used here, this includes any molten or fused and / or molten insulating material 19.

With the fire bar elements according to the invention or the fire bars formed therefrom, as could be shown. Building facades, which are equipped with heat insulation composite systems based on foamed insulating materials, in particular styrene polymers such as polystyrene, are effectively protected against fire propagation or such fire propagation can be suppressed to a significant extent, i. be hampered if the thermal insulation system still has no plaster coating.

The features of the invention disclosed in the foregoing description, in the claims as well as in the drawings may be individually as well as in any arbitrary Combination for the realization of the invention in its various embodiments essential.

With the present invention, a system is provided which allows melting material of an insulating facade to be removed from the fire or supplied to a controlled burn-off, so that fire expansion can no longer take place. Thus, the function of the bolt goes beyond the prevention of the formation of a fireplace far out. Rather, molten material is removed in an efficient and effective manner from the melt nt, so that the melt can cool and is not available as a fuel or at most burns off controlled, without itself still be able to cause a fire or expansion. This is achieved by preventing said burning material from overcoming the edge of the depression. Further, this is accomplished by isolating the region of the depression from an underlying fire. Also, the oxygen supply through the inner wall and the raised upper end of the front side is effectively cut off.

The features of the invention disclosed in the ensuing description, in the claims and in the drawings may be advantageous both individually and in any combination for the realization of the invention.

Claims (17)

Fire bar element with a facade side attachable first side (also called facade side), wherein the first side has a middle orientation, which is a rectified two-dimensional plane assignable,
a second side (also referred to as a front side), with an upper and a lower end, wherein the second side extends from the lower end to the upper end, wherein the façade side opposite portion of the second side and / or the entire second side of the facade side facing away from,
a lower, third side (also called lower side) opposite the upper end and adjoining the lower end,
an outlet or depression adjoining the upper end on the facade side, with a front wall delimiting the inner wall, the inner wall being delimited by the upper end of the front side,
characterized in that the front side has, at least in sections, a continuously and / or graduated decreasing distance to the two-dimensional plane in the direction of the upper end, said distance being determined orthogonally starting from the two-dimensional plane. A fire latching element according to claim 1, characterized in that the front side has a continuously decreasing distance in at least a first portion, said first portion extending to the upper end and preferably having a concave or convex curvature or being substantially flat. A fire-interlocking element according to claim 1 or 2, characterized in that the front side has a stepped decreasing distance in at least a first section, at least one step attachment or a stepped shoulder and / or a stepped structure extending to the upper end. Fire-locking element according to one of the preceding claims, characterized in that the upper end is part of a delimiting strip.
in particular part of a bilateral exposed portion of a delimiting strip. A fire bolt element according to claim 4, characterized in that the boundary strip is made of a different material than the remaining fire bolt element forming a barrier between depression or omission and front, said material preferably having a higher thermal conductivity than the remaining material of the fire bolt element. Fire-stop element according to claim 4 or 5, characterized in that the delimiting strip comprises a metal or a metal alloy and / or a thermal conductivity greater than 0.1 W / (m * K), in particular greater than 5 W / (m * K), and particularly preferably greater 15 W / (m * K). A fire-interlocking element according to one of claims 4 to 6, characterized in that a part of the delimiting strip extending from the upper end is not enclosed by the material of the fire-interlocking element on the front side and on the façade side, wherein said sub-region has a height of at least 1 cm, preferably at least 2 cm and more preferably at least 4 cm and / or said portion, in particular the entire boundary strip, in its mean orientation not more than 45 °, preferably 25 °, deviates from the orientation of the two-dimensional plane. Fire-locking element according to one of the preceding claims, characterized in that there is a wall region between the inner wall and the front side, which tapers in the direction of the upper end and / or in that there is a delimiting strip which tapers in the direction of the upper end. Fire-locking element according to one of the preceding claims, characterized in that the mean distance between the inner wall and the opposite portion of the front side, in particular in the upper region. 5 to 80%, preferably 10 to 70%, and most preferably 20 to 60% of the mean distance of said front-side section to the two-dimensional plane, and / or
that the average distance of the upper end to the two-dimensional plane is 10% to 90%, preferably 20% to 80% and especially preferably at least 30 to 70% of the mean distance of the lower end to the two-dimensional plane, and / or
the maximum depth of the omission or depression, ie the mean height difference between the upper end and the lowest point of the omission or depression, is 10 to 90%, preferably 15 to 80% and most preferably 20 to 70% of the mean height difference between lower and upper end is and / or
in that the mean distance between the upper end and the lower end is greater than the mean distance between the upper end and the maximum distance of the recess or depression remote therefrom. Fire-locking element according to one of the preceding claims, characterized in that it has a longitudinal extent with a length which is greater than its thickness and / or width, preferably at least twice as large as the thickness and / or width of the fire-locking element and / or that Fire latch element is substantially uniform along its longitudinal extent. Fire-locking element according to one of the preceding claims, characterized in that the fire-locking element one, in particular mineral or organic. Coating, preferably on the front side and / or the top and / or bottom and / or on a portion or the entire region of the recess or omission. Fire bar element according to one of the preceding claims, characterized in that front side has at least one substantially vertical portion and / or that the underside has a substantially horizontal central orientation. A fire bar, preferably in a substantially horizontal orientation, comprising at least two or a plurality of fire bar elements according to any one of the preceding claims. Use of the fire bolt element according to one of claims 1 to 12 or the fire bolt according to claim 13 as an oblique or horizontal fire barrier in thermal insulation composite systems for building facades. Use according to claim 14, characterized in that the fire bolt element or the fire bar in the area above falls, especially door and / or lintels, or above building openings, in particular door and / or window openings is arranged as an oblique or horizontal fire barrier. Thermal insulation composite system comprising foamed insulation materials, in particular foamed or extruded styrene polymers, for a building facade and at least one fire-locking element according to one of claims 1 to 12 or a fire-barrier according to claim 13. Building facade, comprising at least one fire bolt element according to one of claims 1 to 12 or at least one fire bar according to claim 13 or a composite thermal insulation system according to claim 16, which comprises a building exterior wall and / or the fire bolt element or the fire bar on its facade side directly or indirectly on a facade by means at least one mineral adhesive and / or organic adhesive and / or fastened by means of dowels or a rail construction.

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