GB2395495A

GB2395495A - Building system with acoustic damping

Info

Publication number: GB2395495A
Application number: GB0227101A
Authority: GB
Inventors: Keith James Hunter Anderson
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-11-20
Filing date: 2002-11-20
Publication date: 2004-05-26
Anticipated expiration: 2022-11-20
Also published as: GB0227101D0; GB2395495B

Abstract

A building system with acoustic damping used to provide floors, walls or ceilings comprises a supporting structure 2, a layer of resilient strips 4, a sheet of acoustic insulator 6 which fills the gaps between the strips and a layer of acoustic sound barrier 8 positioned over the strips and insulator. The resilient strips may be rubber. The acoustic insulator may comprise open celled foam, polyester or bubble wrap. The sound barrier may comprise a mixture of bitumen and aggregate or sand.

Description

Acoustic Building Systems This invention relates to an acoustic building

system and in particular to a system which can be used to provide acoustic floors, walls, or ceilings.

5 A number of acoustic building systems are known and these are predominately flooring systems. These are usually laid on existing floors. One known acoustic flooring systems typically comprise one or more layers of acoustic absorbing material, or isolation fibre laid onto the floor. This material may be e.g. polyester fibre or foam, fibre glass or rockwool. It is relatively low density and has a high degree of compressibility. On top of these layers is laid what is known as the massive layer. This is typically formed from dense rubber or 15 particle board, chipboard, plywood, or plasterboard. On top of this, an overlay flooring board is laid.

The system works on the basis that when e.g. someone walks across the floor the sound created by that person on the overlay board is transmitted into the massive layer 20 which deflects slightly thereby absorbing some of the sound. The acoustic insulation absorbs sound not absorbed by the massive layer thereby preventing it from passing through to a lower floor. The overlay board and the massive layer flex in response to someone walking on the 25 floor and in response to loud noises made above the floor and any sound not absorbed by the flexing is absorbed by the acoustic layer.

One problem with such a system is that because the resilient acoustic layer is compressible, the floor can so seem somewhat spongy to walk upon. Also, if pieces of heavy equipment or furniture, stud partition walls or boards are positioned on the floor the acoustic layer will tend to be compressed by this thereby reducing its efficiency at absorbing sound.

- 2 - Another known system is the cradle and batten system.

In this, a plurality of rubber cradles are used to support wooden battens. The spaces between the battens are filled with acoustic insulation and an overlay board is fixed 5 with screws to the wooden battens. The absence of the massive layer means that these systems are not as efficient at absorbing sound since there is no longer the spreading of sound into the thermal insulation by the massive layer. The efficiency of the system is also lo dependent on the voids between the battens being filled with the insulation material. Also, the system is quite fiddly to install because the cradles have to be positioned correctly and the battens cut to the right length. 15 A variation on this system has a batten provided with a rubber base to give some direct absorption between impacts on the overlay board and the supporting surface.

Preferred embodiments of the present invention seek to overcome some of the drawbacks of the prior art in a

to simple to install system.

In accordance with a preferred embodiment of the invention there is provided an acoustic building system comprising a supporting structure of resiliently compressible strips defining spaces therebetween and 25 positioned adjacent to a surface, an acoustic insulator positioned within the spaces the acoustic insulator having less resilience than the resiliently compressible strips, and an acoustic sound barrier positioned over the strips and acoustic insulator.

so Preferably the resiliently compressible strips comprise rubber strips.

Preferably the acoustic insulator comprises open celled foam or polyester fibre or bubble wrap.

Preferably the sound barrier comprises a board formed 35 from a mixture of bitumen and an aggregate or sand.

Preferably there are two or more layers of sound barrier. Preferably the acoustic insulator is provided in a sheet and overlays the resiliently compressible strips and 5 is compressed in the region of the strips by the sound barrier. In one embodiment, the acoustic building system is a flooring system.

In another embodiment, the acoustic building system 10 is a system fixed to a wall to prevent external sound from entering a room.

In a further embodiment, the acoustic building system is fixed to a ceiling to prevent sound from entering the room in which it is fitted.

In a further embodiment, the acoustic insulator may be provided as a single sheet positioned underneath the resiliently compressible strips.

Preferably, the resiliently compressible strips are provided in a lattice structure which can be cut to a 20 desired size when installing the system.

Preferred embodiments of the invention will now be described in detail by way of example with reference to the accompanying drawings in which: Figure 1 is a cross-section through a flooring system 25 embodying the invention; Figure 2 is a walling system embodying the invention; and Figure 3 is a ceiling system embodying the invention.

In Figure 1 a cross-section through a floor embodying So the invention can be seen. This comprises an existing floor 2 which may be formed from concrete or timber or some other suitable flooring material. On top of this are positioned resiliently rubber strips 4. The strips are

- 4 formed of dense rubber or rubber granules glued together.

They are compressible but are highly resistant to compression and therefore do not deflect significantly when supporting a load. The strips can also be formed 5 from fibre board or closed cell foam or other equivalent materials which are highly resistant to compression. In this particular example, the strips are longitudinal strips extending across a room in which the acoustic building system is being fitted. They are laid at lo spacings sufficiently close for there to be no excessive deformation of the layers subsequently positioned above.

This will depend on the use to which the room in which the system is fitted is to be put.

Between the rubber strips there is a layer of 15 acoustic insulator 6. This may be open celled foam, polyester fibre, bubble wrap, or any other known acoustically insulating material. The acoustic insulator 6 is provided in strip form and laid between the rubber strips. If this method of construction is adopted, then so the preferred way to lay the system will be to lay alternate strips of rubber and acoustic insulator from one side of a room to the other.

Alternatively, the acoustic insulator (which is much more compressible than the rubber strips) is provided in a 25 single sheet which is laid over or under the rubber strips. When subsequently layers are laid on top of the acoustic insulator, it is severely compressed in the region of the rubber strips and substantially fills the gaps between the rubber strips.

So On top of all of this is laid what is know as the massive layer. This preferably comprises a board like material formed from a mixture of bitumen and an aggregate or sand. This can be a single board although in a preferred embodiment two or more layers of board are used 35 since when the boards flex they move against each other

- 5 - creating friction and thereby absorbing sound energy, and thereby providing additional sound absorption. The bitumen has a tacky surface which creates further friction and energy depletion in addition to the flexing of the 5 massive layer allowed by the deflection of the insulation layer between the rubber strips. The boards are preferably asphaltic boards comprising a sand filled bitumen compound layer sandwiched between two layers of reinforced asphaltic paper.

10 The flooring system is finished off with a flooring product such as a board or laminate 10 laid directly on top of the massive layer. When someone walks across the floor or some other sound occurs, the massive layer flexes, thereby absorbing much of the sound as a result of 15 its density. The remaining sound is absorbed by the acoustic insulator which clamps the reverberation of the massive layer. In addition, the acoustic insulator does provide some support to the massive layer but clearly much less than is given by the rubber strips.

20 When the acoustic insulator is provided in sheet form, it can be laid on top of the rubber strips as discussed above. Alternatively, it may be laid first beneath the rubber strips. The rubber strips are provided in varying depths according to the application to which 25 the acoustic building system is to be put so as to provide differing levels of noise reduction.

In an alternative embodiment, multiple layers of the acoustic building system can be provided. For example, a first layer could be constructed as described above with so rubber strips, a low density of acoustic layer and a massive layer. On top of this could be provided a further layer of rubber strips, a further layer of acoustic insulator, and a further massive layer. All of this could be finished off with a flooring board.

In an alternative embodiment, the rubber strips could be substituted with wooden battens with a resilient rubber layer on either their upper or lower sides.

In a further alternative, the system can be used on 5 top of a floor constructed using a cradle and batten system. In this, the battens sit in cradles provided on the floor. A layer of board or some other planar support is then laid across the battens and the acoustic building system installed on top of this, finishing off with a lo layer or overlay board. Some additional insulating material can be provided in the cavities formed between the lower layer of the board, the battens and the existing floor. In a further embodiment, the rubber strips may be 15 provided in a preformed lattice, which can be cut to the size of the room required, thereby increasing the speed of installation. Such a preformed lattice could be provided in roll form.

Figure 2 shows a modification of the system for use 20 on a wall. The purpose here, is to protect the room from external noise rather than the case of the floor which is to protect a room beneath from noise created within the room in which the product is laid.

The wall 12, has fixed to it isolated timber or steel 25 battens 14. To these are fixed the massive layer 16 using metal fixings. Preferably the fixings provided space the acoustic system from the wall.

Next are positioned the acoustic insulator 18 and the rubber strips 20. These may be fixed to the massive layer so by glue or by screwing or by nailing. As discussed in relation to the flooring system, the rubber strips can be either directly adjacent to the massive layer or may have the insulator between them and the massive layer. The wall is then finished with a layer of a chosen walling 35 product such as plaster board 22. This is fixed through

the acoustic system to the battens using specially adapted fixings. In this embodiment there is shown some insulation 24 provided between the massive layer 16 and the wall 12.

5 This is not essential but is preferably provided to make some additional acoustic insulation before any sound waves passing through the wall 12 reach the massive layer.

In use, the acoustic system primarily protects a room from external noise passing through the wall 12. Noise 10 which passes through causes the massive layer 16 to deform, thereby absorbing most of the noise but transmitting the remainder through to the acoustic insulator 18 which then absorbs a significant part of the remaining noise. Thus, little noise passes through.

15 A system such as that illustrated in Figure 2 will also have some sound insulation properties in relation to noise generated within the room and will prevent much of these passing outwardly through the wall.

The details shown in Figure 2b illustrates a possible so form for metal fixings for the wall system. This comprises a U shaped fixing 24 which is positioned on the wall and within which is carried the metal or wooden batten 14 which is secured by screws or nails 26 which pass through the fixing 24 and into the batten 14.

25 In an alternative embodiment, a layer of board can be provided fixed to battens on the wall. On top of this is positioned a first layer of rubber strips followed by a layer of acoustic insulator and then the massive layer.

On top of this is positioned a further layer of rubber so strips and a further layer of acoustic insulator, the whole structure being finished with another layer of plasterboard or other walling material. Such an arrangement will act as an acoustic insulator for noise coming from either side of the wall.

- 8 - A system for use on a ceiling is shown in Figure 3a with a detail of metal fixings used at Figure 3b. The order of the various layers for use on the ceiling is the same as that of Figure 2 since the purpose of the system 5 is to prevent noise from above being passed into the room.

Thus, the layers are given the same reference numbers as in Figure 2. The system is supported by a number of acoustic hangers 30 which are fixed to the ceiling with screws 32. The hangers 30 support elongate steel angle lo beams 34. These extend across the width of a room being covered by the ceiling. Positioned over the vertical portion of the steel angle is provided, formed in extruded plastic or metal, a further angle member 36 on which a horizontal portion extends in the opposite direction to 15 the horizontal portion of angle 34. Angle 36 is fitted over the vertical portion of angle 34 using a preformed hook section 38. The two horizontal portions of the angle members 34 and 36 are used to support the rubber strips 14 of this embodiment of the invention. The vertical portion 20 of the angle extends upwardly through the massive layer 16. The hangers 30 and angle 34 are first positioned on the ceiling. Portions of the acoustic system are the fitted between adjacent the beams formed from steel angle 25 34. A section formed from the massive layer 16, the acoustic insular 18, and with a rubber strip 14 on either side are provided, preferably held together with some way.

The whole section can then be supported on the horizontal position of steel angle 34 whilst the other side is 30 brought up to an adjacent steel angle 34, the additional angle 36, is the brought up beneath it and its hook positioned over the vertical portion of steel angle 34, thereby gaining support on both sides to the acoustic system. This continues until the ceiling has been 3 5 covered.

- 9 Positioned above the massive layer there is preferably provided a further layer 44 of acoustical absorbent material such as fibre glass or rockwool.

Fitted beneath the angle 34 is a resilient batten 38 s to which is fixed the plaster board 22 which finishes the ceiling. It will be appreciated that the construction of this system is slightly more complex than that of the flooring and wall systems since the acoustic insulator 16 has to be lo provided in strips between the angle members 34 which are used to support the ceiling. Nevertheless, when the whole ceiling has been covered with the acoustic system it will provide a good sound insulation.

As with the wall, a further layer of insulation 24 IS can be provided between the massive layer 16 and the existing ceiling 40.

Claims

- 10 Claims

1. An acoustic building system comprising a supporting structure of resiliently compressible strips defining spaces therebetween and positioned adjacent to a surface, 5 an acoustic insulator positioned between the spaces the acoustic insulator having less resilience than the resiliently compressible strips, and an acoustic sound barrier positioned over the strips and the acoustic insulator. lo

2. An acoustic building system according to claim 1 in which the resiliently compressible strips comprise rubber strips.

3. An acoustic building according to claim 1 or 2 in which the acoustic insulator comprises open celled foam or is polyester fibre or bubble wrap.

4. An acoustic building system according to claim 1, 2 or 3 in which the sound barrier comprises a board formed from a mixture of bitumen and an aggregate and/or sand.

5. An acoustic building system according to any preceding 20 claim in which the sound barrier comprises two or more layers.

6. An acoustic building system according to any preceding claim in which the acoustic insulator is provided in a sheet.

- 11 -

7. An acoustic building system according to claim 6 in which the sheet is positioned between the resiliently compressible strips and the acoustic sound barrier.

8. An acoustic building system according to claim 6 in which the sheet of acoustic insulator is positioned between the resiliently compressible strips and the supporting structure.

9. An acoustic building system according to any preceding claim comprising a flooring system.

lo

10. An acoustic building system according to any preceding claim comprising an acoustic wall panel.

11. An acoustic building system according to any preceding claim comprising a ceiling panel.

12. An acoustic building system according to any preceding is claim in which the resiliently compressible strips are provided in a lattice structure.

13. An acoustic building system substantially as herein described with reference to any one of Figures 1, 2 or 3 of the drawings.