GB2322146A

GB2322146A - Acoustically-insulating floor

Info

Publication number: GB2322146A
Application number: GB9802875A
Authority: GB
Inventors: John Finlayson Danskin
Original assignee: Danskin Flooring Systems Ltd
Current assignee: Danskin Flooring Systems Ltd
Priority date: 1997-02-14
Filing date: 1998-02-12
Publication date: 1998-08-19
Anticipated expiration: 2018-02-12
Also published as: GB2322146B; GB9802875D0; GB9703028D0

Abstract

A floor construction comprising a supporting structure and a floating raft construction on said supporting structure and said floating raft construction comprises floor boards (3) attached to battens (4). Each batten has at least one horizontal surface faced with a resilient fibrous layer (5) adapted to provide resilience under load whilst providing enhanced sound attenuation properties. The fibrous layer preferably comprises polyester fibres in the form of a felted and thermally bonded web with an upper, denser stratum, and a lower, less dense stratum.

Description

Improved Floor Construction This invention relates to a floor construction and in particular a sound attenuating floor construction for use on sub floors such as screeds, concrete sub-floors or units, or joisted sub floors in a timber frame construction.

Traditional floor systems comprise raft type arrangements especially where building regulations specify that floors must be built to comply with a certain standard for airborne and impact sound attenuation. Several types of arrangements have been used in order to provide adequate attenuation to the transmission of impact and airborne sound by using mineral wool quilt or glass fibre quilt which is placed underneath the timber battens associated with the raft construction. Strips of closed cell foam have been used underneath the battens also to attenuate impact sound.

As a result of current building regulations, all specified acoustic floor constructions in the Building Regulations utilise a combination of timber battens with or without resilient closed cell foams on the underside in combination with mineral wool quilts to reduce impact and airborne sound in party floors.

These traditional floor constructions have the disadvantage that there is evidence to suggest that the mineral wool quilt (which performs well when initially laid) breaks down and compacts completely over a period of time because its fibres are generally brittle in structure. This compaction and breakdown of the fibres impairs the floors springiness and ability to absorb vibrations thereby allowing impact sound to pass to the floor below.

Another disadvantage of using the mineral wool quilt is that it is an irritant and can cause handling and health problems to the hands and lungs of those working with it.

Furthermore it tends to degrade in the presence of water.

The aim of the present invention is to overcome and mitigate the disadvantages in traditional specified floor constructions by providing in one resilient layer the sound attenuation properties required by the current Building Regulations.

According to one aspect of the present invention there is provided a floor construction comprising a supporting structure and a floating raft construction on said supporting structure and said floating raft construction comprising floor boards fixably attached to battens, each batten having at least one horizontal surface faced with a resilient fibrous layer adapted to provide resilience under load whilst providing enhanced sound attenuation properties.

Preferably the fibrous layer is polyester fibre.

Preferably the fibrous layer is attached to the lower surface of the batten, Advantageously the fibrous layer can be attached to the upper surface of the batten.

Preferably the adapted fibrous layer has at least two distinct strata to provide reliance under load whilst providing enhanced sound attenuation properties.

Advantageously each strata has a differing distinct and discrete density.

Preferably at least one stratum should be of a great enough density to prevent a sound bridge being formed between the timber batten and the concrete sub-floor where the sub-floor is uneven.

Advantageously another stratum will be of a sufficiently low density to permit vertical deflection under a load thereby allowing impact sound to be absorbed in the fibrous layer.

Advantageously the fibrous nature of the resilient layer will absorb airborne sound and reduce the reverberation of airborne sound in the floor cavity.

In another aspect of the invention the fibrous layer is positioned directly on top of the timber joists.

According to a further aspect of the invention there is provided a floor construction comprising a supporting structure and a floating raft construction on said supporting structure and said floating raft construction comprising a floor panel having a resilient fibrous layer attached to the lower horizontal surface thereof, said fibrous layer adapted to provide resilience under load whilst providing enhanced sound attenuation properties.

The invention will now be described in more detail with reference to the accompanying drawings.

Figure 1 A cross sectional view of the floor construction in accordance with a first embodiment of the invention.

Figure 2 A cross sectional view of the floor construction in accordance with a second embodiment of the invention.

Figure 3 A cross sectional view of the floor construction in accordance with a third embodiment of the invention.

Figure 4 A cross sectional view of the floor construction in accordance with a fourth embodiment of the invention.

A floor construction is provided which comprises a supporting structure for example concrete (1) slab (as shown in figures 1 and 4) or floor or joisted floor (2) (as shown in figure 2 and 3), onto which is positioned a floating raft construction.

The floating raft construction comprises timber floor boards or lengths of suitable chipboard or plywood (3) fixed to timber battens (4). The battens (4) are of any suitable length but are generally determined by the length dimensions of the supporting structure. The battens (4) have a substantially square or rectangular cross sectional area and can be made from any suitable material such as softwood timber but may also include sheet material such as plywood, oriented strand board (OSB), chipboard, hardboard, medium density fibreboard (MDF), and the like.

The floor boards (3) are attached to the upper horizontal surface of the timber batten (4) by any suitable fixing means such as nails, screws or adhesive.

Generally, on the lower and/or upper surface of each batten (4) is located a strip of the resiliently pliant fibrous material (5). The fibrous material (5) is of substantially the same dimensions as the aforementioned surfaces of the batten (4) and is attached to the surface of the batten (4) by a suitable bonding material, adhesive or staples.

The fibrous material (5) layer itself comprises a resilient layer manufactured from 100% polyester fibre. The fibres are processed and layered into a web of a given weight. This weight is typically 1000-1500 grams/m2. The web is then felted to create a layer comprising two strata of a discrete densities. The web is then thermally bonded.

Although in this particular example there are only two strata this is only for the purposes of illustration and should not be regarded as limiting on the scope of invention as there can be more than two strata included in the adapted fibrous layer.

The upper stratum (5a) is typically 5-15 mm but preferably 5-12 mm thick with a typical density of in the range of 65-150 kg/m3 but preferably 85 kg/m3. The lower stratum (5b) is typically 8-25 mm (but can be as low as 5 mm) but preferably 10-15 mm (but can be as low as 7 mm) thick with a typical density in the range of 25-50 kg/m3 but preferably 45 kg/m3. The top stratum (5a) has to be of a high enough density to prevent a sound bridge being formed between the timber batten (4) and a concrete sub-floor (1) especially where the sub-floor (1) is uneven (as shown in figures 1 and 4). The more dense fibre protects the less dense fibre from damage and provides a better surface for adhesion to the timber battens or flooring panels. On the other hand the lower strata (5b) has to be of a low enough density to permit vertical deflection under a load which thereby allows impact sound to be absorbed in the fibrous layer (5). These two distinct strata (Sa, 5b) in the fibrous layer (5) prevent complete compaction of the layer (5) and over a period of time act as a resilient cushioning layer against impact from above preventing impact sound being transmitted through the floor construction. The less dense stratum (5b) compresses under loading from above and the fibrous nature of the resilient layer absorbs airborne sound preventing it from reverberating in the floor cavity.

The less dense stratum (5b) then recovers it position when the load is removed.

The overall thickness of the fibrous layer (5) can vary but is generally in the range of between 13-40 mm but preferably 17-25 mm (but it can be as low as 12 mm or as high as 27mm or thereabouts). The thickness and density of the strata (5a, 5b) can be varied in the manufacturing process as required depending on the type of floor construction in which it is to be used.

In another embodiment the fibrous layer (5) can be placed directly on top of the timber joists (2) as a sound insulating layer (as shown in figure 2).

In a further embodiment a sheet or strips of the fibrous layer (5) can be fixed directly to the underside of a flooring panel (3) such as chipboard, plywood medium density fibreboard or cement based particle board to provide a sound insulating layer for use in the refurbishment of existing buildings (as shown in figure 3).

It should be noted that in timber framed constructions it may be that there is also a layer of plasterboard immediately below the flooring panel for prevention of fire.

The advantages of the present invention are that construction costs are cheaper and installation times shorter because less components are used than in traditional specified constructions. In fact manufacture of the product is cheaper than prior art laminated products and traditional specified constructions as it is manufactured from a single low cost constituent. Unlike traditional mineral wool quilts, polyester fibre will absorb only a small amount of water causing little effect to the product. Furthermore the polyester fibre is physiologically inert. Unlike mineral wool quilt it does not cause skin irritations and breathing difficulties in the workers who are laying the floor system.

It should also be noted that mineral wool fibres are brittle and over time the resiliency of the product can deteriorate thus impairing its performance as a sound attenuator. However the polyester fibres in the present invention have much greater flexibility than mineral wool and are less likely to suffer such deterioration. This is because polyester fibre is extended and stretched to align the molecular structure in order to obtain good strength and modular characteristics.

Claims

1. A floor construction comprising a supporting structure and a floating raft construction on said supporting structure and said floating raft construction comprising floor boards fixably attached to battens, each batten having at least one horizontal surface faced with a resilient fibrous layer adapted to provide resilience under load whilst providing enhanced sound attenuation properties.

2. A floor construction according to Claim 1 wherein the fibrous layer is polyester fibre.

3. A floor construction according to Claims 1 or 2 wherein the fibrous layer is attached to the lower surface of the batten.

4. A floor construction according to Claims 1 or 2 wherein the fibrous layer can be attached to the upper surface of the batten.

5. A floor construction according to Claim 1 wherein the adapted fibrous layer comprises a fibrous layer having at least two distinct strata.

6. A floor construction according to Claim 5 wherein each strata has a differing distinct and discrete density.

7. A floor construction according to Claims 5 or 6 wherein at least one stratum should be of a great enough density to prevent a sound bridge being formed between the timber batten and the concrete sub-floor where the sub-floor is uneven.

8. A floor construction according to Claims 5 or 6 wherein another stratum will be of a sufficiently low density to permit vertical deflection under a load thereby allowing impact sound to be absorbed in the fibrous layer.

9. A floor construction according to any one of the preceding claims wherein the fibrous nature of the resilient layer will absorb airborne sound and reduce the reverberation of airborne sound in the floor cavity.

10. A floor construction according to claim 1 wherein the fibrous layer is positioned directly on top of timber joists.

11. A floor construction comprising a supporting structure and a floating raft construction on said supporting structure and said floating raft construction comprising a floor panel having a resilient fibrous layer attached to the lower horizontal surface thereof, said fibrous layer adapted to provide resilience under load whilst providing enhanced sound attenuation properties.