WO1998011313A1

WO1998011313A1 - Improvements in or relating to flooring

Info

Publication number: WO1998011313A1
Application number: PCT/AU1997/000605
Authority: WO
Inventors: Michael Anthony Luke Hynes
Original assignee: T & G Hynes Pty Ltd
Current assignee: T & G Hynes Pty Ltd
Priority date: 1996-09-13
Filing date: 1997-09-12
Publication date: 1998-03-19
Anticipated expiration: 1999-03-13
Also published as: AUPO232096A0

Abstract

A method for forming a floating floor is disclosed. The method includes the steps of laying a bottom layer (11) of cushioning material over a subfloor, overlaying the bottom layer (11) with a substantially rigid intermediate layer (12) without adhering the bottom layer (11) to the intermediate layer (12), overlying the intermediate layer (12) with an upper floor surface layer (13) and bonding the intermediate and floor surface layers (12, 13) to one another, to form a floating floor. A floating floor constructed according to the methods described is also disclosed.

Description

IMPROVEMENTS IN OR RELATING TO FLOORING

The present invention is directed to improvements in or relating to flooring, and more particularly but not exclusively to improvements to floating floors.

BACKGROUND OF THE INVENTION

Floating floor systems are generally known, and their use is becoming increasingly widespread. One arrangement of the published prior art comprises three layers laid over a sub floor such as a concrete slab. This arrangement of three layers comprises a bottom iayer of cork, an intermediate layer of cement sheet adhered to the bottom layer, and an upper layer comprising wooden boards adhered to the intermediate layer. The bottom and intermediate layers of this arrangement are normally pre-fabπcated by adhering the two layers together in a factory, following which the pre-assembly comprising the two adhered layers is transported to the site for installation by laying the pre-assembly over the sub floor, followed by adhering the wooden boards to the intermediate layer of the pre- assembly.

It has been observed that the performance of floating floors is influenced to a significant extent by moisture changes in the environment in which the floor is installed. Variations in moisture, and particularly increases in moisture, tend to have an adverse effect on the integrity of the floor. In addition, it is generally accepted practice that the materials to be used in the arrangement described need to be delivered to the installation site in the region of 48 to 72 hours prior to installation to assist the materials to acclimatise to local temperature and humidity conditions.

Accordingly whilst the arrangement described above may provide satisfactory performance in some circumstances, an intermediate layer in the form of masonite is particularly susceptible to attack by moisture, which can lead to swelling of the masonite sheet and hence to unevenness in the floorboards laid over the masonite sheet.

Any ingress of moisture into the intermediate layer in these circumstances is difficult to treat, and can lead to eventual breakdown in the structural integrity of the intermediate layer. Depending on the severity of damage, it can lead to the layered floor having to be lifted and replaced.

In addition, the prior art arrangement described above requires a significant degree of plant and labour involving pre-assembly, including cutting the bottom layer to size in the factory, pre-fabrication of the bottom and intermediate layers by adhering them to one another followed by transportation of the pre-assembly to the site for installation has been observed to add to the cost of the flooring system as a whole. It has now surprisingly been found that a satisfactory flooring system can be achieved even though the bottom and intermediate layers are not adhered to one another.

SUMMARY OF THE INVENTION

The present invention accordingly provides in one embodiment a method for forming a floating floor, the method including the steps of laying a bottom layer comprising a cushioning material over a sub floor, overlaying the bottom layer with a substantially rigid intermediate layer without adhering the bottom layer to the intermediate layer, overlaying the intermediate layer with an upper floor surface layer, and adhering the intermediate and upper layers together, whereby to form a floating floor.

The present invention provides in another embodiment a flooring system constructed according to the methods described herein.

A floating floor according to the invention is a floor which is not fixed to the sub floor but is capable of expansion and contraction without significant or undue separation of the floor boards from one another in the case where the upper layer comprises floor boards.

A sub floor according to the invention is preferably a concrete slab or other suitable foundation. The sub floor is preferably constructed and arranged to receive bottom, intermediate and upper layers according to the invention laid over the sub floor.

A bottom layer according to the invention preferably comprises a material capable of providing cushioning for the floor in conventional manner. The bottom layer is preferably substantially water-resistant. The bottom layer may have sound attenuating properties to attenuate the sound of the footfall of persons walking over the finished floor, and to attentuate other airborne sound.

The bottom layer may be in the iorm of an underlay or equivalent as is generally known in the art.

The bottom layer may be formed from a foam material. The oam material may be an open cell foam or a closed cell foam. One example of a closed cell foam considered suitable for use in the practice of the present invention comprises Soflon™, which is a material formed as a closed cell foam and arranged to prevent moisture passing through the material. Other open cell and closed cell foam materials are envisaged as being within the scope of the present invention.

Where the bottom layer is in the form of an underlay or equivalent, the bottom layer is preferably provided in sheet or roll form whereby the material can be laid over the sub floor by being spread or rolled out over the sub floor. Preferably the bottom layer is laid to the edges of the sub floor, wall or other boundary defining the floor area desired to be laid, and cut to the desired dimension. A plurality of rolls may be provided whereby to cover the desired floor area. In this embodiment the bottom layer may comprise a plurality of longitudinal strips. The strips may be joined together if desired such as by stapling, nailing, adhesion or other form of joining. In one particularly preferred arrangement the strips forming the bottom layer are joined together by means of water-resistant tape or equivalent placed along the edges of adjacent strips. The intermediate layer may then be laid over the bottom layer.

In one particularly preferred embodiment, the bottom layer is rolled onto the sub floor in a plurality of longitudinal strips, and tape is applied to the bottom layer along the longitudinal edges of adjacent strips to hold the strips together whereby to form a substantially continuous bottom layer.

It is preferred that the bottom layer is not adhered to the sub floor, whereby a floating floor can be established having no adhesion between the bottom layer and the sub floor as well as having no adhesion between the bottom layer and the intermediate layer.

The bottom layer may in another embodiment comprise a material which is settable on applying the bottom layer over the sub floor. The material may be thermosettable. The arrangement is preferably such that the settable material is capable of bonding to the sub floor following application of the material to the sub floor. In this form of the invention, whilst there is a bonded interface between the bottom layer and the sub floor, there is no bonded interface between the bottom layer and the intermediate layer, and hence the characteristics of a floating floor can be established wherein the intermediate and upper layers are not fixed to the sub floor.

The bottom layer may comprise a flowable material. The material may be sufficiently flowable to facilitate trowelling, pumping or spraying of the material over the sub floor. The material may be selected so as to be substantially self-levelling when pumped onto the sub floor.

Where the material comprising the bottom layer is pumpable, the material may be provided in a suitable container capable of facilitating pumping of the material over the desired floor area of the sub floor. The material is preferably cured for a sufficient time to allow it to set, following which the intermediate layer may be laid over the bottom layer.

In another embodiment, the bottom layer may comprise a polymeric material, such as rubber or a rubber -like material.

The intermediate layer preferably has sufficient density and/or thickness so that the intermediate layer is stabilised by its own weight and by gravity whereby to prevent shifting such as slipping of the layer relative to an adjacent layer when the floor is walked upon. A floor produced in accordance with the present invention is accordingly maintained substantially stable by gravity.

The intermediate layer preferably has sufficient rigidity to provide structural support for the upper layer laid over the intermediate layer. The intermediate layer preferably provides the finished floor with the desired stability when downward pressure, such as the pressure of a furniture item, or a combined downward and shear force such as that generated by a person's foot when walking, is applied to the laid floor surface.

The intermediate layer preferably comprises a material selected so as to be resistant to attack by moisture. The moisture content of the intermediate layer is preferably controlled so as to be within a predetermined range prior to installation. Close control of the moisture content of the intermediate layer has been found to assist in maintaining the desired structural integrity of the laid floor.

In one embodiment the intermediate layer may be formed from a material selected so as to be substantially non-porous. Other materials for forming the intermediate layer are envisaged as being within the scope of the present invention.

In one preferred embodiment the intermediate layer comprises a fibre cement sheet. The fibre cement sheet may be any suitable thickness. The fibre cement sheet preferably has a thickness in the range of about 2 to 8mm, and more preferably in the range of about 4 to 7mm.

Another example of an intermediate layer suitable for use in the practice of the present invention is plywood. An intermediate layer of plywood may be any suitable thickness. The plywood preferably has a thickness in the range of about 2 to 8mm, and more preferably in the range of about 4 to 7mm.

The intermediate layer may be provided in sheet or roll form whereby the intermediate layer material is laid over the bottom layer, such as by being placed or rolled out over the bottom layer where the intermediate layer is in sheet, strip or roll form, to the edges of the bottom layer, wall or other boundary defining the floor area desired to be laid, and cut to the desired dimension. The upper layer may then be laid over the intermediate layer.

Where the intermediate layer is in the form of a plurality of sheets, strips or rolls, the sheets, strips or rolls are preferably laid over the bottom layer with gaps between adjacent sheets or strips to allow for the possibility of expansion of one sheet or strip relative to another.

The bottom and intermediate layers preferably have a combined thickness of in the region of about 4 to 10mm, and more preferably in the range of about 6 to 9mm when laid. The intermediate layer may comprise a plurality of longitudinal strips. The strips may be joined together if desired such as by stapling, nailing, adhesion or other form of joining. In an embodiment where the intermediate and upper floor surface layers each comprise a plurality of longitudinal strips, the strips of one layer are preferably laid in a direction transverse to the direction of the other layer. This arrangement has been observed to assist in contributing to the structural integrity of the layers when lai .

The moisture content of the material comprising the intermediate layer is preferably controlled whereby to minimise the effect of moisture changes in the intermediate layer causing expansion of the intermediate layer. Such expansion may create gaps between adjacent sheets of the intermediate layer. The intermediate layer preferably has a moisture content approximating the equilibrium moisture content of the environment in which a floor according to the invention is to be laid.

The upper floor surface layer is preferably a finished or substantially finished surface such as a pre-sanded surface suitable for being walked on, or for having items such as furniture placed on it.

The floor surface layer may be a wooden surface. The floor surface layer is preferably timber floorboards, parquetry or other finished floor surface as is known in the art. In the case where the floor surface layer comprises floor boards, the boards are preferably laid in side-by-side relationship whereby the edges of adjacent floorboards substantially abut one another. Preferably the edges of the floorboards merely abut one another and are not machined or otherwise modified which would otherwise produce an interlocking construction.

This arrangement in combination with an intermediate layer providing stability has been observed to obviate the need for tongue and groove or other interlocking constructions whilst allowing for expansion and contraction of the floor in response to ambient air temperature and/or humidity variations.

Where a wooden surface such as timber boards is used as the floor surface layer the moisture content of the wood is preferably controlled whereby to minimise the effect of moisture changes in the wood causing gaps to appear between boards. The boards preferably have a moisture content approximating the equilibrium moisture content of the environment in which a floor according to the invention is to be laid.

The floorboards may be sanded, varnished, stained or otherwise surface treated to give the desired finished effect.

The floorboards may be pre-sealed. Pre-sealing according to the invention may include one or more coats of a penetrating sealer. This may be followed by one or more coats of a gloss sealer. In one preferred embodiment the floor surface layer comprises pre-sanded floor boards. The floor boards may be given a desired finish by light sanding and/or lacquering.

Where the floor surface layer comprises floor boards, the floor boards are preferably pre-glued on their underside.

The intermediate and floor surface layers may be affixed to one another by contact adhesion between the layers. In one embodiment the floor surface layer is affixed to the intermediate layer by applying an adhesive to the upper surface of the intermediate layer, following which the pre-glued undersides of the floor boards are contacted with the upper surface of the intermediate layer, whereupon a bond between the floor surface layer and the intermediate layer is formed. In general no drying or curing time is required as a satisfactory bond between the layers is achieved in this way. Other forms of adhesion between the intermediate and floor surface layers are envisaged as being within the scope of the present invention.

In one preferred embodiment, a floor surface layer comprising floor boards pre- glued on their underside is affixed to an intermediate layer comprising fibre cement sheet by applying an adhesive to the surface of the fibre cement sheet facing the floor surface layer and allowing the adhesive to dry. The two layers are then placed in contact with one another whereby an adhesive bond between layers is achieved. The floor surface layer may then be struck repeatedly with a rubber mallet to assist contact between the layers, whereupon the layers are secured to one another and the floor is established.

Any adhesive capable of providing the level of adhesion required to maintain the integrity of the two layers is suitable for use in the present invention. One such suitable adhesive is a latex adhesive.

The intermediate and floor surface layers may in one embodiment be formed as a pre-assembly.

A moisture barrier may be provided for flooring according to the present invention. The moisture barrier is preferably capable of preventing the bottom layer from coming into direct contact with moisture on the sub floor. The moisture barrier may be in the form of a membrane. The membrane is preferably interposed between the sub floor and the underside of the bottom layer. In one embodiment the moisture barrier comprises a sheet of plastics material. The sheet may be formed from a black plastic. Other materials for forming a moisture barrier are envisaged within the scope of the present invention.

The bottom layer may of itself constitute a moisture barrier, particularly if the bottom layer is in the form of a closed cell foam. In an arrangement where the bottom layer comprises a closed cell foam a separate moisture barrier is not essential. Whilst not essential to the present invention, a surface of a layer according to the invention may be provided with frictional characteristics whereby to prevent the layer shifting unduly relative to an adjacent layer in response to a person walking over the floor. A layer surface may include roughening, ribs, ridges, or other treatment providing a frictional interface with an adjacent layer. Other constructions providing frictional characteristics are envisaged within the scope of the invention. In one arrangement the underside of the intermediate layer ie. the surface of the intermediate layer which is adjacent the bottom layer, may be provided with frictional characteristics. In another arrangement a flooring system according to the invention may include a separate layer having frictional characteristics. The frictional layer may be interposed between the bottom and intermediate layers and/or the intermediate and floor surface layers.

In one preferred embodiment according to the present invention, a moisture barrier in the form of a black plastic is laid over a sub floor, a bottom layer comprising a closed cell foam is laid over the moisture barrier to the desired thickness, following which an intermediate layer comprising fibre cement sheet is laid over the bottom layer without adhering the underside of the intermediate layer to the bottom layer. The underside of the floor surface layer comprising floor boards is then adhered to the intermediate layer to form flooring in accordance with the invention.

BRIEF DESCRIPTION OF PREFERRED EMBODIMENT

The invention will now be described with reference to particularly preferred embodiments in which:

Figure 1 is a cross-sectional representation of a flooring system in accordance with one embodiment of the present invention.

Turning to the drawing, Figure 1 shows generally a flooring system 10 comprising a bottom layer 11 laid over sub floor 14 which in the embodiment shown comprises a concrete slab, an intermediate layer 12 laid over bottom layer 11, and an upper floor surface layer 13 laid over intermediate layer 12.

In the preferred embodiment shown, the bottom layer 11 comprises Soflon™, which is a closed cell foam material, the intermediate layer 12 comprises fibre cement sheet, and the upper layer 13 comprises pre-sanded timber floor boards pre-glued on their underside. The fibre cement sheet and the floorboards are selected to have a moisture content falling within a predetermined range approximating the equilibrium moisture content of the surrounding environment. Close control of moisture content of the intermediate and upper layers has been observed to assist in producing flooring which can maintain the desired structural integrity over time.

In use, a bottom layer 11 comprising Soflon™ in roll form is laid out over the concrete slab 14, and cut to the desired dimensions. Intermediate layer 12 comprising fibre cement sheeting is placed over the bottom layer 11 without adhesion or other direct bonding to the bottom layer 11. The fibre cement sheeting is laid so that there is a gap between adjacent sheets to allow for expansion between adjacent sheets.

A latex adhesive is applied to the facing surface of the intermediate layer 12 and allowed to dry. The intermediate and upper floor surface layers are then affixed to one another by contact adhesion with the floorboards placed in substantially abutting side-by- side relationship. The floorboards are arranged so that their longitudinal axes are transverse to the longitudinal axes of the fibre cement sheeting of the intermediate layer. This arrangement is intended to prevent the timber floorboards from possibly collapsing along the joins of the intermediate layer. By laying the intermediate and upper layers transverse to one another, the gap between the sheets of the intermediate layer runs underneath timber boards and not along the length of the board. If the gap was to run the length of the board the chances of a board collapsing under the force of say a stiletto heel would be likely to increase.

The upper layer 13 is subsequently struck repeatedly with a rubber mallet to secure the two layers to one another.

Following establishment of the floor, the floorboards are given a light sanding and are lacquered to produce a finished floor.

Moreover, flooring produced in accordance with the present invention has been found to obviate the need for adhering the bottom and intermediate layers together whilst providing a satisfactory floating floor.

In addition, it has been observed that flooring constructed in accordance with the present invention allows for expansion and contraction of the floor boards without affecting the integrity of the flooring as a whole.

Furthermore, flooring produced according to the invention has been observed to have a finished appearance closely approximating a standard tongue and groove floor without the expensive machining of the edges of the floorboards required to produce the tongue and groove floor boards. While it has been convenient to describe the present invention in relation to particularly preferred embodiments, it is to be appreciated that various modifications, alterations and/or additions to the embodiments described herein may be made within the scope and ambit of the present invention.

Claims

1. A method for forming a floating floor, said method including the steps of laying a bottom layer of cushioning material over a sub floor, overlaying said bottom layer with a substantially rigid intermediate layer without adhering said bottom layer to said intermediate layer, overlaying said intermediate layer with an upper floor surface layer, and bonding said intermediate and floor surface layers to one another, whereby to form a floating floor.

2. A method according to claim 1, wherein said bottom layer is substantially water- resistant.

3. A method according to claim 1, wherein said bottom layer is formed from an open cell or a closed cell foam material.

4. A method according to claim 1. wherein said bottom layer is not adhered to said sub floor.

5. A method according to claim 1, wherein said bottom layer comprises a flowable material capable of being trowelled, pumped or sprayed onto said sub floor.

6. A method according to claim 5, wherein said flowable material is substantially self-levelling.

7. A method according to claim 1, wherein said floor surface layer comprises floor boards pre-glued on their underside and said intermediate layer comprises fibre cement sheet having adhesive on a face of said fibre cement sheet facing said floor boards, said method further including the step of contacting said layers with one another whereby to achieve an adhesive bond between said layers.

8. A method according to claim 7. wherein said fibre cement sheet has a thickness in the range of about 4 to 7mm.

9. A method according to claim 1 , wherein said intermediate layer has a moisture content approximating the equilibrium moisture content of the environment in which said floor is to be laid.

10. A method according to claim 1, wherein said intermediate layer is selected from the group consisting of plywood and fibre cement sheet.

11. A method according to claim 1 , and further including the step of interposing a moisture barrier between said sub floor and said bottom layer.

12. A method according to claim 1 , wherein said floor surface layer is a wooden surface.

13. A method according to claim 12, wherein said wooden surface has a moisture content approximating the equilibrium moisture content of the environment in which said floor is to be laid.

14. A method according to claim 12, wherein said wooden surface comprises floor boards pre-glued on their underside whereby to facilitate bonding of said floor boards to said intermediate layer and wherein said floor boards are placed in substantially abutting side-by-side relationship over said intermediate layer when bonding said floor boards to said intermediate layer.

15. A method according to claim 1, wherein the combined thickness of said bottom and intermediate layers is in the region of 6 to 9mm when laid.

16. A floating floor constructed according to the method of claim 1.

17. A method for forming a floating floor, said method including the steps of laying a moisture barrier of a plastics material over a concrete sub floor, laying a bottom layer comprising one or more rolls of a closed cell foam material over said moisture barrier to the edges of the sub floor, wall or other boundary defining the floor area to be laid, cutting said bottom layer to the desired dimension, overlaying said bottom layer with a substantially rigid intermediate layer selected from the group consisting of fibre cement sheet and plywood without adhering said intermediate layer to said bottom layer, and overlaying said intermediate layer with a floor surface layer comprising floor boards pre- glued on their underside including bonding said intermediate and floor surface layers to one another and wherein said floor boards are laid in substantially abutting side-by-side relationship over said intermediate layer, whereby to form a floating floor.

18. A floating floor constructed according to the method of claim 17.