The present invention relates to a method for forming a sound-dampening inner wall construction comprising a building stud comprising a first flange portion of a wood fibre material having a first mounting surface for mounting a building board, a second flange portion of a wood fibre material having a second mounting surface for mounting a building board, and a middle portion connecting the flange portions forming a space between the flange portions, which flange portions have a substantially rectangular cross section and are arranged substantially in parallel with each other, and which middle portion comprises a plane metal plate with a thickness of less than 0.7 mm, extending substantially orthogonally between the flange portions.

The middle portion is formed by a relatively thin metal plate, which makes the middle portion relatively flexible, contributing to giving the wall construction its sound-dampening properties. A thin middle portion leads to less sound transmission between the flange portions than a thicker middle portion.

The flange portions being made of a wood fibre material enables attachment of wall boards to the building studs by a spike connection. Thereby the wall boards can be fixed by spikes to the building stud instead of being screwed, which simplifies the mounting of the wall boards and also shortens the time consumption for mounting.

For certain sound-dampening inner wall constructions, it is necessary that the thickness of the middle portion does not exceed 0.7 mm for the desired sound dampening to be obtained. As regards building studs of the type described initially, the inventor has disclosed that in certain cases, it can be a challenge to obtain a reliable connection between a building stud and a wall board while maintaining the sound-dampening capacity of the wall construction. An object of the present invention is to at least partially solve this problem.

According to one aspect, the present invention relates to a method for forming a sound-dampening inner wall construction, comprising: a building stud comprising first and second substantially parallel flange portions of a wood fibre material, which flange portions each has a substantially rectangular cross section, a predetermined thickness and a substantially plane mounting surface, wherein the mounting surface of the first flange portion is arranged substantially in parallel with and turned away from the mounting surface of the second flange portion as well as a middle portion connecting the flange portions, forming a space between the flange portions, which middle portion comprises a plane metal plate with a thickness of less than 0.7 mm, extending substantially orthogonally between the flange portions, at least one wall board with a predetermined thickness, and a spike connection comprising a spike device with a length that is greater than the sum of the wall board thickness and the flange portion thickness, but smaller than the sum of the wall board thickness, the flange portion thickness and the length of the middle portion.

The method comprises the following steps: the building stud is mounted between a floor support element and a roof support element, and the wall board is mounted to the building stud by the wall board being disposed against the mounting surface of one of the flange portions and attached to the flange portion by said spike device being driven through the wall board and into and through the flange portion at an orthogonal distance from the middle portion, which is in the interval of 5-20 mm. Said at least one wall board can comprise a first wall board and a second wall board, and the method can comprise the first wall board being mounted to the building stud by the first wall board being disposed against the first mounting surface and attached at the same by driving the spike device through the first wall board and through the first flange portion at an orthogonal distance from the middle portion, which is in the interval 5-20 mm, and the second wall board being mounted to the building stud by the second wall board being disposed against the second mounting surface and attached thereto by the spike device being driven through the second wall board and through the second flange portion at an orthogonal distance from the middle portion, which is also in the interval 5-20 mm. Thereby wall boards can be arranged on both sides of the building stud.

Said space can have a first space portion arranged on a first side of the middle portion and a second space portion arranged on a second side of the middle portion, and the method can comprise said at least one wall board being attached to the flange portion by a first spike device being driven through the wall board, through the flange portion and into the first space portion at an orthogonal distance from the middle portion, which is in the interval 5-20 mm, and a second spike device being driven through the wall board, through the flange portion and into the second space portion at an orthogonal distance from the middle portion, which is also in the interval 5-20 mm. Thereby the said at least one building stud can be attached to the building stud with spike devices arranged on both sides of the middle portion, which further increases the reliability of the spike connection.

The method can comprise a first wall board being attached to a flange portion by a first spike device being driven through the first wall board, through the flange portion and into the first space portion at an orthogonal distance from the middle portion, which is in the interval 5-20 mm, and a second spike device being disposed edge to edge with the first wall board and attached to the flange portion through a second spike device being driven through the second wall board, through the flange portion and into the second space portion at an orthogonal distance from the middle portion, which is also in the interval 5-20 mm. Thereby two wall boards can be joined over a building stud. Preferably, the wall studs are disposed on the mounting surface of the flange portion, so that the edge portions of the wall boards are brought to the centre of or in alignment with the middle portion.

Said spike device can comprise staples or spikes, and said operation of the spike device can be carried out with a spike or staple gun.

According to yet another aspect, the present invention relates to a sounddampening inner wall construction comprising a building stud and a wall board with a predetermined thickness, which is attached to the building stud, which building stud comprises: first and second substantially parallel flange portions of a wood fibre material, which flange portions each has a substantially rectangular woodcut, a predetermined thickness and a substantially plane mounting surface, wherein the mounting surface of the first flange portion is arranged substantially in parallel with and turned away from the mounting surface of the second flange portion, and a middle portion connecting the flange portions, forming a space between the flange portions, which middle portion comprises a plane metal plate with a thickness of less than 0.7 mm, extending substantially orthogonally between the flange portions.

The building stud and the wall board are connected with each other by a spike connection comprising a spike device with a length that is greater than the sum of the wall board thickness and the flange portion thickness, but smaller than the sum of the wall board thickness, the flange portion thickness and the length of the middle portion, whereby the spike devices are arranged through the wall board and attached in the flange portion at an orthogonal distance from the middle portion, which is in the interval 5-20 mm.

Said flange portions can be made of homogeneous wood or wood fibre elements manufactured of chipboard or wood fibre laminate.

Said flange portions can have a thickness in the interval 12-20 mm.

Said middle portion can have a thickness in the 0.4-0.6 mm interval, for example 0.5 mm, and the wall boards can be gypsum boards.

With building studs of the present type, i.e. comprising a middle portion formed of a metal plate with a thickness of no more than 0.7 mm, good sound properties are obtained as mentioned above. However, the inventor has disclosed that if the spiking of the wall boards takes place in a region relatively far away from the middle portion, there is a risk that the middle portion will bend at the spiking moment, which may lead to an unsatisfactory spike connection.

Experiments have shown that this problem can be avoided if the spiking takes place within an orthogonal distance from the middle portion, not exceeding 20 mm. Generally, the closer the middle portion is to the spiking, the more stable the spike connection.

Spiking too close to middle portion gives rise to another problem, though. As mentioned above, the relative flexibility of the middle portion contributes to the good sound properties of the building stud. If the spike device gets into contact with the middle portion, for example if the spike device is mounted in contact with the middle portion or so close to the middle portion that it risks getting into the contact with it at a later building moment, there is a risk that the sound properties of the building stud deteriorate, because contact between the spike device and the middle portion restricts the flexibility of the middle portion and thereby also its sound-dampening properties.

Experiments have shown that this is avoided by the spike device being arranged at an orthogonal distance from the middle portion, which is greater than 5 mm.

By the spike connection being established at an orthogonal distance from the middle portion, which is in the 5-20 mm interval, a reliable spike connection can thus be established between the wall board and the building stud without risk of the sound-dampening properties of the building stud being compromised.

By using a spike device with a length exceeding the total thickness of the wall at the attachment of the wall boards and the flange portion, but which is smaller than the sum of the thickness of the wall board, the thickness of the flange portion and the length of the middle portion, the advantage is obtained that the tips of the spike device, after mounting, are not surrounded by stud material. This prevents movements in the flange portion, for instance due to moist variations, from causing the spikes to "come loose" and thereby cause protruding spike heads in the wall boards.

The width of the building stud, meaning the distance between the mounting surfaces, can be in the 40-100 mm interval, for instance 45 mm, 70 mm or 95 mm. The cross section dimensions of the flange portions can be adapted to the desired measures and performance. The thickness of the flange portion can be in the 12-20 mm interval. For mounting gypsum wall boards, the cross section dimension of the respective flange part can for example have a width of 40 mm and a thickness of 15 mm. This width provides ample space for joining two wall boards on the same building stud, and at the same time this thickness offers good conditions for attaching the wall boards securely to the building studs.

The floor and roof support elements can be formed by plate rails, but other support elements that provide the required support to the building studs can alternatively be used. Floor and roof support elements can for example be formed of lying studs of homogeneous wood attached in a floor and roof construction, respectively.

In the following the invention will be described in more detail with reference to accompanying patent drawings, where, unless stated otherwise or implicitly appears from the context, the same reference numerals indicate the same components.

Fig. 1 shows an inner wall construction comprising wall boards mounted on a stud framework.

Fig. 2 shows an embodiment of a building stud with mounted wall boards.

Fig. 3 shows a further embodiment of a building stud with mounted wall boards.

Fig. 1 shows an inner wall construction 1 comprising a building stud and wall boards 20 mounted on the building stud. The building stud comprises lying floor support elements 2 4 roof support elements 4 and standing building studs 10 mounted between the support elements 2, 37. The support elements 2, 4 are attached in a floor and roof construction, respectively (not shown in the figure). In the shown embodiment, the support elements 2, 4 consist of rails with U-shaped cross section in which the building studs 10 are mounted. However, the support elements can be configured in other manners as long as they provide the required support to the building studs. The support elements can for example consist of lying studs of homogeneous wood attached in a floor and roof construction, respectively.

Fig. 2 shows an embodiment of a building stud 10, which can be included in the inner wall construction 1 according to Fig. 1. The building stud 10 comprises a first flange portion 12 and a second flange portion 14 of a wood fibre material and a middle portion 16 connecting the flange portions 12, 14. Each flange portion 12, 14 has a substantially rectangular cross section. In the shown embodiment, the respective flange portion 12, 14 is formed of uniform boards of homogeneous wood, but the flange portions 12, 14 can have different shapes and comprise or be made of other types of wood fibre elements, for instance wood fibre elements made of chipboard or wood fibre laminate.

The flange portions 12, 14 can for instance have a cross section dimension of 15 mm times 40 mm, but it appears that the cross section dimension can be adapted to the desired wall construction.

The middle portion 16 is formed of an elongated board element of plate with a thickness of less than 0.7 mm, which gives the building stud 10 good sounddampening properties. The thickness of the middle portion can for instance be in the 0.4-0.6 mm interval, for example 0.5 mm.

The connection between the middle portion 16 and the flange portions 12, 14 can be a spike connection, a screw connection, a glue connection or a combination of a spike, screw or glue connection. Alternatively or as a supplement a groove (not shown) can be accommodated in the respective flange portion, in which groove a free edge of the middle portion 16 can be attached. The first flange portion 12 has a first mounting surface 13 for mounting one or more wall boards on a first side of the inner wall construction 1. The second flange portion 14 has a second mounting surface 15 for mounting one or more wall boards on a second side of the inner wall construction 1. The middle portion 16 forms a space 17 between the flange portions 12 and 14. The middle portion 16 is thus an element forming a distance between the flange portions 12, 14.

In order to form the inner wall construction 1 according to Fig. 1 , the floor support element 2 and the roof support element 4 are attached in said floor and roof construction, respectively, in a common vertical plane. Subsequently, building studs 10 are arranged between the support elements 2, 4, so that they obtain a substantially vertical alignment and are attached to the support elements 2, 4. The building studs 10 can for example be mounted in the support elements 2, 4 at a mutual centre-centre distance of 600 mm.

When the building studs 10 have been mounted in the support elements 2, 4, one or a plurality of first wall boards 20a are mounted to the building studs 10 by the one or more first wall boards 20a being disposed against the first mounting surfaces 13 of the building studs 10 and attached thereto by a spike device being 32 driven through the first wall board 20a and through the first flange portion 12, but not into the second flange portion 14. Each spike device has a length Ls, which is greater than the sum of the thickness Tv of the wall board 20a and the thickness Tpof the flange portion 12 and less than the sum of the thickness Tv of the wall board 20a, the thickness Tpof the flange portion 12 and the length LL of the middle portion 16, i.e. Tv + TF < LS < TV + TF + LL. Thereby, the advantage is obtained that the tips of the spike device 32, after mounting, are not surrounded by stud material. This prevents movements in the first flange portion 12, for instance due to moist variations, from causing the spike device 32 to "come loose" and thereby cause protruding spike heads in the wall board 20. A wall board 20a is mounted to a building stud 10 by the wall board 20a being disposed against the mounting surface 13 of the flange portion 12 and attached to the flange portion 12 by said spike device 32 being driven through the wall board 20a and into and through the flange portion 12 at an orthogonal distance A from the middle portion 16, which is in the interval of 5-20 mm. In other words, the wall board 20a and the flange portion 12 are, by a spike connection 30 arranged within a region R extending in parallel with and between 5 mm and 20 mm from the middle portion 16. As discussed above, a reliable spike connection is thereby obtained, while maintaining the good sound properties of the building stud 10.

If the inner wall construction 1 , is to be covered with wall boards on both sides, one or a plurality of second wall boards 20b are mounted to the building studs 10 by that or the second wall boards 20b being disposed against the second mounting surfaces 15 of the building studs 10 and attached thereto by a spike device 32 being driven through the second wall board 20b and through the second flange portion 14, but not into the first portion 12. In the same manner as for the wall board 20a, the second wall board 20b is mounted to the building stud 10 by the wall board 20b being disposed against the mounting surface 15 of the flange portion 14 and attached to the flange portion 14 by the spike device 32 being driven through the wall board 20b and into and through the flange portion 14 at an orthogonal distance A from the middle portion 16, which is in the interval of 5-20 mm.

The spike device 32 can for example be staples 32a or spikes 32b that are preferably applied by means of a staple pistol or a spike pistol, respectively.

The building stud 10 can have a substantially H-shaped cross section, whereby the space 17 has a first space portion 17a arranged on a first side of the middle portion 16 and a second space portion 17b arranged on a second side of the middle portion 16.

If so desired, the spike device can be arranged on both sides of the middle portion 16, as illustrated for the wall board 20c in Fig. 3, in which case the spike device 32 is driven through the wall board 20c and into and through the flange portion 14 on each side of the middle portion 16, i.e. within a region R, which on both sides of the middle portion 16 extends in in parallel with and between 5 mm and 20 mm from the middle portion 16.

If a first and a second wall board are to be joined over a mounting surface, it can be advantageous, as illustrated for the wall boards 20d and 20e in Fig. 3, if the first wall board 20d is disposed at the mounting surface 15 with its edge portion at the height of or at the centre of the middle portion 16 and attached to the flange portion 14 by the spike device being driven through the first wall board 20d and through the flange portion 14 and into the first space portion 17a and the second wall board 20e being disposed at the mounting surface 15 edge to edge with the first wall board 20d and attached to the flange portion 14 by the spike device being driven through the second wall board 14 and through the flange portion 14 and into the second space portion 17b.

The invention is described above on the basis of a plurality of possible embodiments. However, the person skilled in the art will realize that other embodiments, or variants thereof, are possible within the scope of the following patent claims.