The invention relates to a device to be arranged in a floor construction according to the independent claim.

The invention contributes to the technical field of floor constructions and in particular to those constructions, which can comprise a layer of screed but is not limited thereto (e.g. oriented strand boards (OSB), high density fiberboards (HDF), medium density fiberboards (MDF), low density fiberboards (LDF) or plywood are also possible). The invention relates to the problem of impact sound reduction (or footfall insulation) and airborne sound insulation in vertical and horizontal directions in such a floor construction as well as the mechanical stability of the layer of screed, e.g. prefabricated screed.

In construction, there is an increase in efforts to reduce sound transmission within and between rooms and/or storeys of a building. New norms such as DIN 4109-1 :2018-01 specify sound transmission limits, particularly for apartment buildings, hotels and hospitals, that are often not achieved. To reduce the sound transmission, e.g. the vertical sound transmission, a dampening layer can be positioned beneath hard flooring. Additionally sound insulating strips can be positioned between the flooring and adjacent walls to decrease the sound transmission to neighbouring rooms, e.g. to the rooms below, via the walls.

For example, a floor construction can be arranged on a floor substrate or raw floor (respectively a raw ceiling). A layer of insulating material which might comprise, or allow to fix, an underfloor heating can be arranged on the floor substrate. A layer of screed can be arranged atop the insulating layer as prefabricated screed (also known as dry screed, e.g. gypsum fibre board) or as screed mortar (e.g. flowing screed). Among others, the above mentioned prefabricated screed or screed mortar may comprise calcium sulfate or cementitious materials (e.g. cement, Portland cement, etc.). Typically, floor covers such as tile, parquet, vinyl, carpet, etc. can be disposed atop a prefabricated screed or screed mortar.

Structurally similar elements to the device of this invention are used as expansion or movement joints to avoid crack formation in concrete floors or different screeds. However, these joints generally do not sufficiently decouple acoustically. In addition, particularly prefabricated screed elements tend to buckle and tilt on impact, because the necessary load transfer of the free ends is often not taken into account.

In conventional floor constructions it is known to arrange a resilient partition strip at expansion joints in the screed layer of a floor construction. For example, in the state of the art, DE 197 44 350 A1 discloses a strip that is fixed by a U-shaped fastening bracket which cannot separate adjacent screed sections acoustically. The fastening bracket is of a solid material and allows the propagation of sound waves along the plane of the surface of the floor construction. This results in poor impact sound and poor airborne sound properties of the floor construction. Another disadvantage is that the fastening bracket has no means to support a screed element from below. Hence, the use of these fastening brackets in e.g. a dry screed layer would result in the dry screed elements sinking into the insulation layer below, especially in the case of a vertical impact on the edge of the dry screed element.

Moreover, it is known from DE 295 18 574 U1 to arrange a T-shaped profile to form an expansion joint in a screed. The T-shaped profile comprises a first cardboard angle element and a second cardboard angle element in between which an insulation material is placed. However, this expansion joint requires many parts and the cardboard material is disadvantageous at the construction site because of its structural weakness, in particular in the presence of water. Also, this expansion joint cannot prevent the edges of the screed from breaking off or sinking into the insulation below.

The object of the invention is therefore to provide a device to be arranged in a floor construction comprising screed (or any of the other options mentioned above) which overcomes or at least reduces the disadvantages known from the prior art and in particular allows for an easy assembly, for decreasing the sound transmission between adjacent flooring sections, as well as for improving the mechanical stability. The object of the invention is solved by a device according to the subject matter of the independent claim. The subject matter of the dependent claims relate to preferred technical aspects.

The invention comprises a device to be arranged in a floor construction in between a first flooring section and a (adjacent) second flooring section. The device comprises a base plate (of a size and shape to be) capable of supporting the (edge portion of the) first and second flooring section. Attached to the base plate is a first decoupling element capable of decreasing the sound transmission between the first and second flooring section. The base plate allows for improving the mechanical stability in the floor construction, wherein the first flooring section and the second flooring section are preferably adjacent flooring sections, more preferably adjacent screed sections, even more preferably adjacent prefabricated screed sections.

According to a preferred technical aspect, the base plate and the first decoupling element are separate or formed in one piece. In case of a separate construction, the base plate and the first decoupling element can be attached to each other, in particular by using separate fastening elements or an adhesive material. In the case that the base plate and the first decoupling element are formed in one piece, the material of the base plate (e.g. a rigid material) is different to the material of the first decoupling element (e.g. a flexible material). Preferably, the base plate comprises a recess, e.g. a groove. The recess may have a size and shape to be capable of engaging a first end portion of the first decoupling element in a form fit. In one example, the first end portion has two edges, which can engage in a rectangular recess. Preferably, the recess extends along the entire base plate and accommodates the first end portion along the entire length. Advantageously, the recess is arranged at a top surface of the base plate in a distance of more than 20 mm, in particular more than 40 mm from an edge portion. The distance is sufficient to allow for arranging a portion of a flooring section thereon, preferably on both sides of the first decoupling element. Arranging the flooring section on the base plate with a large contact area between them results in a good mechanical stability of the flooring section. The maximum distance from the recess to the edge portion preferably does not exceed 500 mm, more preferably it does not exceed 200 mm. The recess can be in a central position but other positions are possible, too. According to another advantageous aspect, the first decoupling element is arranged perpendicular, i.e. at a right angle, to the top surface of the base plate. This arrangement allows the first decoupling element to protrude the flooring sections arranged on both sides of the first decoupling element.

In another preferred aspect, the base plate comprises a rigid material, preferably a cementitious material, calcium sulfate material or wooden material. The material is preferably chosen such as to have a high strength to receive compressive forces, which result from supporting the flooring section. The rigid base may have a sufficient thickness to support the edges of the first and the second section and may thus prevent deformation and/or stress of the overlying flooring by static or dynamic load.

In another preferred aspect, the base plate comprises a gypsum fiberboard, a gypsum plasterboard, a wood board or a wooden fiberboard. A gypsum fiberboard is particularly preferred, because of its inherent strength and the frequent use in dry construction.

According to a preferred aspect, the base plate has a thickness in the range of 8 mm to 20 mm, preferably in the range of 9 mm to 13 mm. The mentioned range allows for sufficient stability.

According to a preferred aspect, the first decoupling element may have a thickness of 8 mm to 20 mm, preferably a thickness of 10 to 14 mm.

According to a preferred aspect, the first decoupling element has openings arranged therein. The openings are of a size and shape to be capable of accommodating underfloor heating pipes therein.

In another preferred aspect, the device further comprises a second decoupling element arranged on the top surface of the base plate adjacent to the first decoupling element, preferably on both sides. Preferably, the second decoupling element covers more than 40 %, more preferably more than 60 %, even more preferably more than 80% of the surface area on each side of the base plate. However, it is also conceivable that the second decoupling element covers less than 40 %, e.g. as little as 10 % or less, depending on the material used. Highly efficient material could be applied punctually or as a thin strip or as a strip with recesses. If a flooring section, preferably prefabricated screed, rests on the base plate, the second decoupling element can allow for decreasing the sound transmission from the prefabricated screed to the base element. It is advantageous, if the device further comprises a third decoupling element arranged on the bottom surface of the base plate, i.e. the surface opposite to the first (and the second) decoupling element. In one example, the third decoupling element comprises a footfall insulation element.

The device comprises at least a first decoupling element. It may optionally further comprise a second and/or third decoupling element. The first decoupling element, the second decoupling element and/or the third decoupling element may each independently be made of a flexible material, in particular a natural flexible material or a synthetic flexible material or combination thereof.

It is particularly preferred that the first decoupling element, the second decoupling element and/or the third decoupling element may each independently be made of one of the following group: mineral wool, polyethylene, natural fiber material, synthetic insulation material, EPS, XPS, expanded rubber, or any combinations thereof. According to a preferred aspect of the present invention, it is further possible that many combinations of the three decoupling elements (only first, first and second, first and third, and particularly preferred first, second and third) each made from different or the same materials are present in the device as described.

Another preferred aspect of the invention relates to a floor construction, comprising at least a first flooring section and at least a second flooring section, wherein a device as described herein is arranged in between, i.e. e.g. in between a first flooring section and a second flooring section.

Particularly preferred, the flooring sections are screed, comprising a cementitious material or a calcium sulfate material. In another preferred aspect, the flooring sections are screed, preferably prefabricated screed.

Another aspect of the invention relates to the use of a device as described herein for decreasing sound transmission between flooring sections and/or for stabilizing flooring sections, preferably the edges of flooring sections.

In the following, the invention will be explained in more detail with reference to the drawings. Like reference numerals denote similar features throughout the drawings. The drawings depict: Fig. 1 a device comprising three decoupling elements (first decoupling element, second decoupling element and third decoupling element) to be arranged in a floor construction in between a first flooring section and a second flooring section according to an embodiment of the invention; Fig. 2 a floor construction according to a first example in which the device of Fig. 1 with only the first decoupling element is arranged;

Fig. 3 a floor construction according to a second example in which the device of

Fig. 1 is arranged with the first and a special form of the second decoupling element;

Fig. 4 a floor construction according to a third example in which the device of Fig. 1 is arranged with the first and the third decoupling element; and

Fig. 5 a floor construction according to a fourth example in which the device of

Fig. 1 is arranged with the first and the second decoupling element.

Fig. 1 illustrates a device 1 , which is to be arranged in a floor construction (see Fig. 2 - 5, reference 10) in between a first flooring section and a second flooring section. The device is preferably arranged in a floor construction comprising a prefabricated screed in a manner that a base plate 2 is arranged under adjacent prefabricated screed sections and the first decoupling element 3 is arranged in between adjacent prefabricated screed sections. Hereby, the base plate 2 improves the mechanical stability of the floor construction by supporting the flooring sections, in particular the edges of the flooring sections. In addition, the first decoupling element 3 acoustically decouples the first and second flooring section. In any case, the advantages of the invention are not limited to flooring sections of prefabricated screed.

The shown device 1 comprises a base plate 2 of a sufficient width to be capable of supporting the first and second flooring sections (see Fig. 2 - 5; reference 11 , 12) at their respective side edges.

Attached to the base plate 2 is a first decoupling element 3, which is of a material (i.e. soft and flexible) to be capable of decreasing the sound transmission when mounted between the first and second flooring sections. The base plate 2 and the first decoupling element 3 are fixed to each other in a form fit. The base plate 2 has a recess 21 of a rectangular cross-section with a size, which allows for form fittingly accommodating a first end portion 31 of the first decoupling element 3. The first end portion 31 is shown in Fig. 1 as the lower edge of the first decoupling element 3. The recess 21 is arranged at a top surface 21 1 of the base plate 2, which extends along the entire base plate 2 in a distance of more than 20 mm (preferably more than 40 mm) from both opposite edge portions 212. In this example, the first decoupling element 3 is arranged perpendicular to the top surface 21 1 of the base plate 2.

In the shown example, the base plate 2 comprises a rigid material (i.e. cementitious material, calcium sulfate material or wooden material). It is of particular advantage when the base plate 2 comprises a gypsum fiberboard, a gypsum plasterboard, a wood board or a wooden fiber board. In the shown example, the base plate 2 has a thickness in the range of 8 mm to 20 mm (preferably 9 mm to 13 mm).

The illustrated first decoupling element 3 is made of a flexible material, which can be a natural material or a synthetic material. For example, the first decoupling element 3 is made of one of the following group: mineral wool, polyethylene, natural fiber material, synthetic insulation material, EPS, XPS, expanded rubber or combinations thereof.

According to a variant, which needs no further illustration, the first decoupling element 3 might comprise openings of a size and shape to be capable of accommodating underfloor heating pipes therein. Hence, the size and shape is to be chosen inter alia according to the size of the room and the dimensions of the underfloor heating in which the floor construction is to be arranged.

In the shown example, at the top surface 21 1 of the base plate 2 a second decoupling element 4 is arranged on both sides of the base plate 2 adjacent to the first decoupling element 3. In this example, the second decoupling element 4 may be made of one of the following group: mineral wool, polyethylene, natural fiber material, synthetic insulation material, EPS, XPS, expanded rubber or combinations thereof, preferably of expanded rubber. The second decoupling element 4 allows for reducing the transmission of sound from the flooring section to the base element 2. The illustrated example further comprises a third decoupling element 5 arranged on the bottom surface 213 of the base plate 2. In this example, the third decoupling element 5 may be made of one of the following group: mineral wool, polyethylene, natural fiber material, synthetic insulation material, EPS, XPS, expanded rubber or combinations thereof, preferably of synthetic insulation material. Therefore, good results concerning footfall insulation are achieved.

In Fig. 2 a first example for a floor construction 10 is shown, in which the device of Fig. 1 only with the first decoupling element is arranged.

In the illustrated floor construction 10, the device 1 is arranged with the base plate 2 directly on the floor substrate 6. The base plate 2 has a width in the range of 50 mm to 200 mm (e.g. 100 mm) and is a gypsum fiber board of a thickness in the range of 8 mm to 20 mm (e.g. 9 mm or 13 mm) with a central recess (see reference 21 in Fig. 1). The shown base plate 2 provides a surface of a width in the range of 40 mm to 50 mm (e.g. 44 mm) to arrange a respective flooring section thereon. In between the first flooring section 1 1 and the second flooring section 12, the first decoupling element 3 is arranged. At the sides of the first decoupling element 3 another decoupling element 8, preferably a footfall insulation element is arranged. The first decoupling element 3 is a mineral wool strip of a width in the range of 8 mm to 20 mm (e.g. 12 mm) and a height in the range of 50 mm to 150 mm (e.g. 100 mm). The first flooring section 1 1 and the second flooring section 12 are a calcium sulfate based prefabricated screed of gypsum fiber material with a thickness in the range of 15 mm to 25 mm (e.g. 18 mm or 23 mm). On top of the prefabricated screed sections 1 1 and 12, a floor covering may be arranged.

In Fig. 3, a second example for a floor construction 10 is shown, in which the device 1 of Fig. 1 with the first and a special form of the second decoupling element is arranged.

In this example, a decoupling element 13, preferably a footfall insulation element is integrally formed at the first screed section 1 1 and the second screed section 12 which are for example gypsum fiber boards having an insulation material fixed at the lower surface. In this special embodiment the decoupling element 13 corresponds to the second decoupling element 4. Thus, the decoupling element 13 is preferably made of the same material as the second decoupling element 4, e.g. natural fiber material. In Fig. 4, a third example for a floor construction 10 is shown, in which the device 1 of Fig. 1 with the first and the third decoupling element is arranged.

The illustrated example further comprises a third decoupling element 5 arranged on the bottom surface of the base plate 2, e.g. made of synthetic insulation material. The third decoupling element 5 is in direct contact with the floor substrate 6 and may preferably be present for footfall insulation.

In Fig. 5, a fourth example for a floor construction 10 is shown, in which the device 1 of Fig. 1 with the first and the second decoupling element is arranged.

At the top surface of the base plate 2 a second decoupling element 4 is arranged on both sides. The second decoupling element 4 allows for reducing the transmission of sound from the flooring sections 1 1 , 12 to the base element 2, i.e. by use of an expanded rubber.

However, combinations of the examples as shown above are possible and may have further advantages.