GB2306182A

GB2306182A - Acoustic material and method of use

Info

Publication number: GB2306182A
Application number: GB9520967A
Authority: GB
Inventors: Keith Anderson
Original assignee: Instafibre Ltd
Current assignee: Instafibre Ltd
Priority date: 1995-10-13
Filing date: 1995-10-13
Publication date: 1997-04-30
Anticipated expiration: 2015-10-13
Also published as: GB2306182B; GB9520967D0

Abstract

A method of soundproofing a structure comprises the steps of providing one or more battens 14 and securing the or each batten to the surface 10 and providing an acoustic material comprising a relatively massive layer having opposing first and second surfaces and a layer of reverberation absorbing material bonded to at least one of those opposing surfaces. The acoustic material is attached to the battens and a layer of boarding 26 is secured to the or each batten in such a way that the acoustic material and the or each batten is interposed between the boarding and said surface. An acoustic material for use in soundproofing or modifying sound comprises a relatively massive layer having opposing first and second surfaces and a respective layer of reverberation absorbing material bonded to each of said opposing surfaces.

Description

ACOUSTIC MATERIAL AND METHOD OF USE The present invention relates to an acoustic material for use in soundproofing or modifying sound and to a method of soundproofing a structure having at least one surface.

In the past the internal surfaces of a building have often been formed by securing a plurality of battens to a wall and then securing a layer of boarding material, such as plasterboard, to the battens. Typically the boarding material is then skimmed with a layer of plaster, left to dry and subsequently decorated. Where it has been desired to soundproof or modify the sound within such a building, this has been done by adding various materials either to the external surface of the plasterboard or, more commonly, to the skimmed layer of plaster.

In contrast to this mainstream approach, it has now been identified that the act of securing battens to an existing wall and the subsequent attachment of boarding material to the battens creates a cavity between the boarding and the wall which may provide the composite wall structure with unwanted acoustic properties. To date no attempt has been made to modify the acoustic properties of this cavity.

According to a first aspect of the present invention there is provided a method of soundproofing a structure having at least one surface, the method comprising the steps of providing one or more battens and securing the or each batten to said surface; providing an acoustic material comprising a relatively massive layer having opposing first and second surfaces and a layer of reverberation absorbing material bonded to at least one of said opposing surfaces; attaching the acoustic material to said one or more battens; providing a layer of boarding; and securing the boarding to the or each batten in such a way that the acoustic material and the or each batten is interposed between the boarding and said surface.

Advantageously the acoustic material is interposed between the or each batten and the boarding. Alternatively, the acoustic material may be interposed between the surface and the or each batten and the or each batten secured to the surface by one or more attachment means which pass through the acoustic material and into the surface thereby also attaching the acoustic material to the or each batten.

According to a second aspect of the present invention there is provided an acoustic material for use in soundproofing or modifying sound comprising a relatively massive layer having opposing first and second surfaces and a respective layer of reverberation absorbing material bonded to each of said opposing surfaces.

A number of embodiments of the present invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 is a fragmentary perspective view of a composite wall structure in which part of the layers of boarding and acoustic material have been broken away for the sake of clarity; Figure 2 is a cross-sectional view through the composite wall structure of Figure 1; Figure 3 is a cross-sectional view of a composite wall structure in accordance with a further embodiment of the present invention; and Figure 4 is a cross-sectional view of the further embodiment of Figure 3 as applied to a ceiling.

Referring to Figure 1, there is shown a wall 10 to which there are attached a plurality of battens 12.

The battens 12 may be of any convenient dimensions but might typically be 50mm wide and have a thickness of 25mm. The battens 12 may be secured to the wall 10 in any convenient or conventional arrangement and so, as shown, might comprise a plurality of mutually spaced, vertically extending ribs 14 joined at top and bottom by upper and lower, horizontally extending cross members 16 and 18. The vertically extending ribs 14 may be spaced apart to any convenient extent but each might typically be separated from its neighbour on either side by a distance of, say, 600mm. The battens 12 may be attached to the wall 10 in any convenient manner but typically this is achieved by a plurality of counter-sunk screws 20.

To this network of battens 12 there is attached a sheet-like layer of flexible acoustic material 22. The attachment of the acoustic material 22 defines a cavity 23 with the wall 10 and the battens 12.

In order to be effective in preventing the transmission of sound to the cavity 23, the acoustic material 22 needs to be relatively massive.

Nevertheless, should some sound be transmitted to the cavity 23, the acoustic material 22 preferably also includes one or more reverberation absorbing layers to absorb the sound transmitted to the cavity 23 and thereby provide an additional damping effect. The or each reverberation absorbing layer is preferably formed of a material having a plurality of interconnecting pockets of air. Such a material might therefore be fibrous, downy or fleecy although this need not necessarily be the case as an open-cell foam would be equally effective.

One material which combines both these attributes may be formed by bonding a fibrous carpet underlay manufactured by Gaskell Textiles Limited of Lee Mill, Bacup, Lancashire, OL13 ODJ, United Kingdom and sold under the trade mark BRITANNIA 32 with the relatively massive sound barrier material sold under the trade mark REVAC by Wardle Storeys Plc of Durbar Mill, Hereford Road, Blackburn, Lancashire, BB1 3JU, United Kingdom. Preferably the acoustic material 22 is formed with a respective layer of the fibrous carpet underlay bonded to each of the opposing surfaces of the sound barrier material so as to form a sandwich with the sound barrier material interposed between the two layers of fibrous carpet underlay.

The acoustic material 22 is attached to the battens 12 by a plurality of attachment means 24 and with the reverberation absorbing layer facing towards the wall 10 and thus towards the cavity 23. The attachment means 24 may be of any convenient type and might typically comprise screws, nails, tacks or staples.

One advantage of providing an acoustic material 22 having a respective reverberation absorbing layer bonded to each side of the sound barrier material is that then the attachment means 24 may be so driven into the battens 12 that any head with which the attachment means is provided is received within the outer of the two reverberation absorbing layers. In this way the attachment means 24 may be decoupled from any additional layers of material which may be subsequently applied to the wall.

The composite wall structure is completed by a layer of boarding 26 which overlies the acoustic material and which is attached to the battens 12 by means of a further plurality of attachment means 28.

The further attachment means 28 are driven through the acoustic material 22 and may be of any convenient type such as screws, nails, tacks or staples.

If required the layer of boarding 26 may be skimmed with a layer of plaster which is then left to dry and subsequently decorated.

Despite the fact that the further attachment means 28 comprises a rigid connection between the layer of boarding 26 and the battens 12, it has again been found that by additionally providing an acoustic material 22 having a layer of reverberation absorbing material on that side of the relatively massive layer which faces the layer of boarding 26, the further attachment means 28 may be sufficiently decoupled as to prevent or substantially reduce the transmission of sound to the cavity 23.

Although the method described above is the preferred method for soundproofing a structure comprising at least one wall, it has been found that an alternative method of construction provides equally acceptable results. In this alternative method, the acoustic material 22 is placed adjacent the wall 10 with the layer of reverberation absorbing material facing outwards and is overlain by a network of battens 12. As before the battens 12 are secured to the wall 10 by appropriate attachment means 20 which are driven through the acoustic material 22 and into the wall and thereby serve to retain the acoustic material with respect to the battens. As in the first arrangement, the composite wall structure is then completed by a layer of boarding 26 which is again secured to the battens 12 by a plurality of further attachment means 28.

It will be appreciated by those skilled in the art that in this alternative arrangement the further attachment means 28 provide a rigid connection between the layer of boarding 26 and the battens 12 which enables sound within the building to be transmitted to the cavity 23 which is this time defined between the acoustic material 22, the battens 12 and the layer of boarding 26. However, as in the first embodiment, provided the acoustic material 22 is provided with a layer of reverberation absorbing material on that surface of the relatively massive layer which faces the cavity 23, the sound transmitted to the cavity may be readily absorbed.

Clearly, in such an arrangement there would be no need to provide a layer of reverberation absorbing material on that side of the relatively massive layer which faces the wall 10.

In another arrangement shown in Figure 3, the battens 12 are decoupled from the wall 10 by means of a pair of resilient grommets 30 and 32. Each grommet 30 and 32 has a top hat cross-section and comprises a cylindrical stem portion 34 and, at one end of the stem portion, a flanged portion 36 of increased diameter. Both the cylindrical stem portion 34 and the flanged portion 36 are provided with a communicating throughbore 38 of sufficient diameter as to be capable of receiving a respective one of the attachment means 20.

In use the battens 12 are prepared so as to present a throughbore 40 of stepped cross-section.

The narrower portion 42 of the throughbore 40 is nevertheless sufficiently sized as to be capable of receiving the cylindrical stem portions 34 of the grommets 30 and 32 while the portion of larger crosssection 44 is sized so as to be capable of receiving one of the associated flanged portion 36. In order to decouple the battens 12 from the wall 10 one of the grommets 30 is inserted into the throughbore 40 from a side of the batten 46 remote from that portion of the throughbore 44 of larger cross-section. In this way only the stem portion 34 of the grommet 30 is received within the throughbore 40, leaving the flanged portion 36 to act as a spacer between the wall 10 and the batten 12.The second grommet 32 is inserted into the throughbore 40 from the opposing surface of the batten 48 in such a way that the stem portion 34 abuts the stem portion of the first grommet 30 and the flanged portion 36 is wholly received within that portion of the throughbore 44 of larger cross-section. A selected one of the attachment means 20 having a head 50 is then inserted into the throughbore 38 of the second grommet 32 and guided through the coaxial throughbore 38 of the first grommet 30 and into engagement with the wall 10. As the attachment means 20 penetrates the wall 10, the head 50 is brought into abutting relationship with the flanged portion 36 of the second grommet 32 thereby retaining the batten 12 in spaced relationship with the wall 10.

It will be apparent that by forming the grommets 30 and 32 of a resilient material, such as rubber, the battens 12, and any items attached to the battens, are vibrationally decoupled from the wall 10.

The stepped throughbore 40 is so dimensioned that when the battens 12 have been attached to the wall 10 the head 50 of the attachment means 24 is flush with the outer surface of the battens 48. In this way the composite wall may be completed by the sequential attachment to the battens 12 of the acoustic material 22 and the layer of boarding 26 in a manner similar to that described above in connection with the first embodiment.

Although the present invention has been described with regard to the soundproofing of a wall, it will be apparent that it is equally applicable to any surface within a building such as a floor or ceiling.

Likewise, it will also be apparent that, whereas in the past a separate method of soundproofing has been required for the floor and walls within a particular structure, the present method may be employed to soundproof a structure comprising two or more surfaces which meet at an intersection. For example, where the wall 10 of Figure 1 meets the floor 30, the acoustic material 22 may be arranged so as to extend in a continuous manner over the intersection and overlie both the wall and the floor. The same is true of an intersection between the wall 10 and the ceiling (not shown). The acoustic material 22 overlying the floor or ceiling may then in turn be overlain by a further layer of boarding.In the case of a floor, this further layer of boarding may comprise floorboards, hardboard, chipboard, cement particle board, HDF or MDF board, blockboard, plywood or the like whereas for a ceiling the further layer of boarding may comprise plasterboard, fire liner board or fire protection sheeting.

The bending of the acoustic material 22 at the intersection through the required angle, typically 900, may be facilitated by scoring a groove in one side of the acoustic material of sufficient depth to penetrate the relatively massive sound barrier material.

By extending the acoustic material over the intersection between two adjoining surfaces in this way it will be apparent that the soundproof properties of a building need not be compromised at the intersection as they might otherwise be if the two surfaces were merely overlain by two mutually abutting sheets of acoustic material.

It will also be apparent to those skilled in the art that using the above method the acoustic properties of a particular structure may be modified using a continuous layer of acoustic material which extends from the floor to the walls, from the walls to the ceiling and from the ceiling to the opposing walls thereby totally enclosing the interior space defined by the structure. In this way, for example, the acoustic properties of all three flats in a three tiered structure may be modified simply by soundproofing the central flat.

In applying the third embodiment to ceilings it will be apparent from the modification shown in Figure 4 that only one resilient grommet need be used since the weight of the battens 12, acoustic material 22 and boarding 26 may be relied upon to bias the battens away from the ceiling by whatever distance is permitted by the fastening means 20. However, in order to prevent the battens 12 from riding up towards the ceiling as the acoustic material 22 and the boarding 26 are attached to it, an additional biasing means 52 is preferably provided between the battens and the ceiling. This biasing means 52 may be of any convenient form and might typically comprise either a spring or a sleeve of resilient material surrounding the attachment means 20.

It will be apparent to those skilled in the art that whilst a particular form of acoustic material has been described, both the relatively massive layer and the or each reverberation absorbing layer may be tailored to suit a particular application and, in particular may be of different weights or thicknesses depending upon the application concerned.

Claims

CLAIMS:

1. A method of soundproofing a structure having at least one surface, the method comprising the steps of: providing one or more battens and securing the or each batten to said surface; providing an acoustic material comprising a relatively massive layer having opposing first and second surfaces and a layer of reverberation absorbing material bonded to at least one of said opposing surfaces; attaching the acoustic material to said one or more battens; providing a layer of boarding; and securing the boarding to the or each batten in such a way that the acoustic material and the or each batten is interposed between the boarding and said surface.

2. A method in accordance with claim 1, wherein the acoustic material is interposed between the surface and the or each batten and the or each batten is secured to the surface by attachment means which pass through the acoustic material and into the surface thereby also attaching the acoustic material to the or each batten.

3. A method in accordance with claim 2, wherein the acoustic material is arranged with the layer of reverberation absorbing material facing towards the layer of boarding.

4. A method in accordance with claim 1, wherein the acoustic material is interposed between the or each batten and the layer of boarding.

5. A method in accordance with claim 4, wherein the acoustic material is arranged with the layer of reverberation absorbing material facing towards the surface.

6. A method in accordance with any preceding claim, wherein the surface comprises all or part of a wall or floor and the boarding comprises plasterboard, chipboard, fibreboard, hardboard, HDF or MDF board, blockboard, cement particle board, plywood or the like.

7. A method in accordance with any of claims 1 to 4, wherein the surface comprises all or part of a ceiling and the boarding comprises plasterboard, fire liner board, fire protection sheeting or the like.

8. A method in accordance with any preceding claim, wherein the or each of batten is vibrationally decoupled from the surface.

9. A method in accordance with claim 8, wherein a resilient member is interposed between the or each batten and the means by which the or each batten is secured to the surface.

10. A method in accordance with any preceding claim, wherein the structure comprises a second surface which meets the first surface at an intersection, the acoustic material extending in a seamless manner over said intersection so as to at least partially overlie both said first and second surfaces.

11. A method in accordance with claim 10, wherein the acoustic material overlying said second surface is in turn overlain by a layer of boarding.

12. A method in accordance with claim 10 or claim 11, wherein a groove is scored in the acoustic material to facilitate the bending of the acoustic material at the intersection.

13. An acoustic material for use in soundproofing or modifying sound comprising a relatively massive layer having opposing first and second surfaces and a respective layer of reverberation absorbing material bonded to each of said opposing surfaces.

14. An acoustic material in accordance with claim 13 wherein one or both of said reverberation absorbing layers are formed of a material having a plurality of interconnecting pockets of air.

15. An acoustic material in accordance with claim 13 or claim 14, wherein one or both of said reverberation absorbing layers are formed of a fibrous material.

16. A method of soundproofing a structure substantially as herein described with reference to the accompanying drawings.

17. An acoustic material for use in soundproofing or modifying sound substantially as herein described with reference to the accompanying drawings.

18. A structure which has acoustic properties which have been modified in accordance with the method of claim 16 or the method of any of claims 1 to 12.