WO2000047837A1

WO2000047837A1 - Floating floor underlay

Info

Publication number: WO2000047837A1
Application number: PCT/US2000/003643
Authority: WO
Inventors: Doug Fiechtl
Original assignee: L & P Property Management Company
Priority date: 1999-02-12
Filing date: 2000-02-11
Publication date: 2000-08-17
Also published as: US6189279B1; AU2992300A

Abstract

A floating floor system (10) for installation over a subfloor (14). The underlay (12) has a polymer film (18) with a relatively low coefficient of friction between itself and a floating floor (15) cast to a relatively thin and dense open-celled foam (20) with a relatively high coefficient of friction between itself and the subfloor (14). Also contemplated is a method for installing the underlay (12) between the subfloor (14) and the floating floor (15), wherein the foam surface (28) of the underlay (12) is placed against the subfloor (14) and the floating floor (15) is positioned onto the film layer (18) of the underlay (12).

Description

FLOATING FLOOR UNDERLAY

Field of the Invention

This invention relates to floating floor systems. More

particularly, this invention relates to a floating floor underlay product

and method of installing a floating floor over a subfloor.

Background of the Invention

Products installed on top of a subfloor and under a floor

treatment that aid in the floor treatment's installation are known in the

art. Often, it is desirable to prevent a floor treatment from absorbing

moisture that seeps up through a subfloor that may cause a floor

treatment to degrade or swell, potentially causing the flooring to

buckle to lift away from the subfloor, causing, for example, premature

glue-joint failure. A problem associated with prior art underlays

applied between the floor treatment and subfloor is that their

installation tends to be overly complicated and difficult. One example

of a known underlay product uses a layer of low density thermoplastic foam applied over a subfloor. This foam is generally porous and

allows moisture to seep up through the foam and contact the floor

treatment, which may thereby damage the floor treatment in the

manner mentioned above. In order to prevent this problem, a second

layer of thermoplastic film must be installed over the layer of foam to

act as a moisture barrier. The foam layer and the film layer tend to

shift and fold during installation and must be adhesively tacked both

together and to the subfloor so that shifting or folding is minimized

when laying the floor treatment. Also, the low density foam used in

this system allows vertical impacts, e.g., foot falls, to resonate and be

amplified through the floor treatment where the treatment is laminate

wood flooring, for example, resulting in an undesirably loud floor

installation.

Another underlay system uses a compressed rigid

fiberboard in conjunction with a thermoplastic layer. The fiberboard is

directly applied to a subfloor in small sheets. Small sheets of the rigid

fiberboard installed side by side result in a large number of joints in

the assembled underlay which must be sealed. The large number of

joints to be sealed increases the probability of premature joint failure

from repeated foot falls to the joints since the rigid fiberboard sheets

tend not to give but, rather, to separate relative to each other. As with the above example, in order to make this underlay moisture

impermeable, a thermoplastic film must be adhesively tacked to the

fiberboard . The fiberboard and film assembly degrades and literally

falls apart over time due to repeated vertical impacts to the floor

treatment, i.e., walking over the floor. Once the fiberboard fails, a

soft spot is created under the floor treatment which leads to an

uneven surface and, ultimately, failure of the floor treatment above

the degraded underlay region . This construction is also susceptible to

amplifying the sound of foot falls.

Certain foams are unsuitable for use as flooring underlay.

For instance, a polyethylene foam is a closed cell foam, the closed

cells being under slightly positive pressure from the physical blowing

agent captured therein, formed during the foaming process. The

closed cells are what give the foamed product its resiliency and much

of its thickness. If the foam cells are ruptured, the foam loses its

resiliency and thickness and creates a dead spot in the foam that

leads to degradation of the floor treatment, and increased noise as

mentioned above.

Objectives of the Invention

It has therefore been an object of the present invention

to provide an underlay for a floating floor that facilitates floating floor installation without bunching, folding, or sliding of the underlay

product before or during installation of the floating floor.

Another object of the present invention is to provide a

thin underlay for a floating floor with acoustic damping characteristics

superior to those of the prior art in a one piece composite that resists

bunching, folding, or sliding prior to or during installation of the

floating floor.

It is another object of the present invention to provide a

method of installing a floating floor over a subfloor.

Summary of The Invention

The objectives of the present invention are achieved by

providing in the preferred embodiment a composite underlay product

for a floating floor made from a moisture impermeable vinyl film to

which an open cell latex foam is directly cast. The open cell latex

foam allows lateral and vertical moisture transmission therethrough.

As used herein, the vinyl film creates a moisture impermeable

underlay when laid over a subfloor and under a floating floor and

seams created between abutting sheets of underlay are sealed with

moisture impermeable tape.

The latex foam surface of the composite underlay has a

relatively high coefficient of friction between itself and a subfloor so that when placed against the subfloor prior to installation of a floating

floor, the underlay grips the subfloor and does not shift and fold . The

vinyl film surface of the composite underlay has a relatively low

coefficient of friction between itself and a floating floor so that when

the floating floor is installed against this film surface of the underlay,

the floating floor easily slides over the film surface, preventing

bunching of the composite underlay. Because the film is permanently

cohered to the foam, no bunching or separation occurs between the

two components of the underlay during installation or use.

The underlay of the present invention is thin, dense and

soft producing low durometer readings on the Shore 00 Scale. This

combination acts as an efficient acoustic dampener to absorb noise

created by foot falls transmitted through the floating floor and also

absorbs more kinetic energy than polyethylene foam underlays. The

latex foam is of open cellular structure. As a result, the underlay does

not lose its resiliency and will not degrade beneath a floating floor

over time due to repeated vertical impacts, thereby prolonging the life

of the floating floor.

Also contemplated is a method for installing the underlay

between the subfloor and the floating floor, wherein the subfloor is

cleaned of debris, the foam surface of the underlay is placed against the subfloor and position the floating floor onto the film layer of the

underlay. Seams formed between strips of underlay are optionally

taped .

Brief Description of the Drawings

Fig . 1 is a partially cutaway perspective view of the

installation of a floating floor according to the present inventive

system;

Fig . 2 is a cross section of Fig . 1 taken along line 2-2;

and

Fig . 3 is a close-up view of the cross section of Fig. 2

showing an alternative embodiment of the underlay.

Detailed Description of the Preferred Embodiment

As is seen generally in Figs. 1 -3, in the preferred

embodiment of the present inventive system 10 for installing a

floating floor 1 5 over a subfloor 1 4, an underlay 1 2 is laid over the

subfloor 1 4 made of concrete, wood, or other materials common in

subfloor construction. The floating floor 1 5, e.g., vinyl flooring,

modular wood flooring and the like, is thereafter placed against the

underlay 1 2.

The underlay 1 2 is a composite of a moisture

impermeable film 1 8 cohered to an open-celled foam 20. As will be understood herein, the term "cohered" means any suitable process

known in the art to permanently join the film 1 8 to the foam 20,

including, for example, direct casting and laminating. As will be

understood herein, the term "moisture impermeable" means a water

transmission value of less than .007 oz/yd²/hr (239 mg/m²/hr) . In the

preferred embodiment, the film 1 8 is polyvinylchloride or

polyurethane. However, other moisture impermeable polymer films

may be used, e.g ., polyethylene, polypropylene. In order to be

moisture impermeable, the thickness of the film 1 8 used is important.

The film 1 8 should be no less than 0.002 inches (0.005 cm) thick,

with a preferred range of about 0.002 inches (0.005 cm) to about

0.008 inches (0.02 cm) thick, and have a weight in the range of

about 2.0 oz/yd² (67.5 g/m²) to about 8.0 oz/yd² (269.9 g/m²) .

In the preferred embodiment, the film 1 8 is manufactured

by calendaring . As will be understood by those in the art, the film 1 8

may be manufactured by any other suitable process, e.g ., extrusion

and blowing.

In the preferred embodiment, the foam 20 is an open-

celled, mechanically frothed expanded latex foam. As will be

understood herein, the term "open-celled" means having the

characteristic property of allowing air or moisture to pass therethrough. In the preferred embodiment, the foam 20 has a

density greater than 1 0 lb/ft^J ( 1 60.2 kg/m³), with a preferred range of

about 1 1 to about 1 5 lb/ft³ ( 1 76.2 to 240.28 kg/m³) . Also in the

preferred embodiment, the foam 20 has a thickness in the range of

about 0.045 inches to about 0. 1 inches (0.1 1 cm to 0.25 cm), with a

preferred thickness of 0.075 inches (0.1 9 cm) . Because the foam 20

is open celled, the underlay 1 2 allows moisture to travel both laterally

and vertically therethrough. In order to make the underlay 1 2

moisture impermeable when installed under a floating floor 1 5, seams

30 between abutting strips of underlay 1 2 must be sealed, as

discussed further below.

As can be seen in Table 1 , samples of a latex foam in

accordance with the principles of the present invention have a much

lower average durometer value on the Shore 00 Scale when

compared to samples of closed cell polyethylene foam over thirty-six

runs. Also, the latex foam samples in Table 1 have a much higher

density (1 1 .23 lb/ft³) ( 1 79.9 kg/m³), than the polyethylene foam

samples (2.1 1 lb/ft³) (33.8 kg/m³) , tested above. This combination of

lower durometer value and higher density relative to closed cell

polyethylene foam imparts desirable sound damping characteristics to

the latex foam when used as a component of an underlay. Thus, a thin, pliable and soft, yet relatively dense latex foam 20 has sound

damping characteristics that tend to muffle and deaden typical low

frequency acoustic energy generated by walking over an un-

dampened floating floor as is discussed further below. Open-celled

polyvinylchloride and polyurethane foams may also be used in the

underlay 1 2 in place of the latex foam 20.

Table 2 shows results of three separate tests performed

to measure the sound emitted from a golf ball dropped onto a floating

floor surface with no underlay, a polyethylene foam underlay and a

latex foam underlay in accordance with the present invention, from a

height of 1 2 inches. The test was performed with Extech Instruments

407736 sound level meter conforming to IEC 651 , ANSI S1 .4 TYPE 2

at 1 8 inches from the point of impact. The floating floor was placed

over a concrete subfloor. The sound level meter was placed 1 8

inches from the intended impact of the golf ball off of, but

immediately adjacent to an edge of the floating floor measuring sound

resonating through the floating floor. The sound level meter was set

to detect and hold the maximum sound level emitted by the floating

floor when the golf ball was dropped thereon. This was repeated

twenty times for each of the floating floor with no underlay, floating

floor with polyethylene foam underlay, and floating floor with latex foam underlay. As seen in Table 2, the values of the same floating

floor with no underlay, polyethylene underlay, and a latex foam

underlay in accordance with the present invention are compared. A

nearly 3dB average reduction in sound intensity is achieved by the

latex foam underlay over no underlay and a nearly 2.5 dB reduction

over the polyethylene underlay.

As is seen in Table 3, a latex foam underlay in

accordance with the present invention absorbs kinetic energy better

than a polyethylene foam underlay. In order to test the kinetic energy

absorption of a latex foam underlay in accordance with the present

invention compared to the kinetic energy absorption of a polyethylene

foam underlay, a golf ball was first dropped from an elevated surface

of constant height onto a concrete subfloor and its rebound height

from the subfloor is recorded to achieve a baseline value for the golf

ball's rebound. This procedure is repeated a number of times in order

to calculate a baseline average value of kinetic energy absorbed of

the golf ball bouncing off the baseline target for comparison to the

amount of kinetic energy absorbed by each underlay product.

Next, different thicknesses of each underlay product

were placed on the subfloor, each thickness of each underlay being

subjected to the same number of golf ball drops. The average rebound of the golf ball from each thickness of each underlay was

measured .

Each time the golf ball is dropped from the constant

height onto the subfloor, latex foam underlay target and polyethylene

foam underlay target, the ball has a first potential energy prior to

being dropped. At the top of the ball's rebound from each of the

aforementioned respective surfaces, the ball, at its rebound apex, has

a second potential energy. The ball's second potential energy when

rebounding from the respective underlays was compared with the

second potential energy of the golf ball rebounding from the subfloor,

and the difference therebetween represents the kinetic energy

absorbed by the latex foam and polyethylene foam underlays.

The latex foam underlay tested had a density of 1 1 .8

lb/ft³ ( 1 89.0 kg/m³), and the polyethylene foam underlay tested had a

density of 2.1 lb/ft³ (33.6 kg/m³) . The test was performed by

dropping a golf ball onto various thickness of each underlay from a

height of 37.5 inches (93.5 cm) . Various thicknesses were used to

eliminate the tendency for the underlays to "bottom out" under

impact. The rebound height of the golf ball from each underlay was

recorded and the percentages of kinetic energy absorbed was

calculated by comparing the second potential energy from the golf ball rebound off each underlay to the potential energy of the golf ball

at its rebound apex when dropped onto the subfloor. This is a test to

determine the ability of each product to absorb and distribute energy

within the product. The latex foam underlay absorbed, on average,

almost three times as much kinetic energy as the polyethylene foam

underlay of the same thickness, as seen in Table 3.

TABLE 1

Laminate Floor Underlay Hardness Comparison

Shore 00 Durometer Scale

TABLE 2 Drop Test Sound Intensity Comparison

Average vs no underlay vs PE underlay

TABLE 3 Kinetic Energy Absorption Comparison

In the preferred embodiment, the foam 20 is directly cast

to the film 1 8, by a process known in the art. It will be understood

by those in the art that the foam 20 and the film 1 8 components also

may be cohered together by any suitable process known in the art,

e.g ., adhesively bonding, or laminating the foam 20 and film 1 8

components together.

In an alternative embodiment (Fig . 3) , the foam 20 is

cohered to a carrier 22, e.g ., a polymer textile, for example, a spun-

cast, extruded or carded needle-punched homopolymer or a

copolymer of polyester, polypropylene, polyethylene, polyolefin,

polyamide or acrylic material or other woven or knitted natural fibers

to create a substrate composite 24. The foam 20 is cohered to the

carrier 22 by any suitable process known in the art. In the preferred

embodiment, the carrier 22 has a thickness in the range of about

0.006 inches (0.01 5 cm) to about 0.025 inches (0.06 cm) and has a

weight in the range of about 0.4 ( 1 3.6 g/m²) to about 2.0 oz/yd²

(67.8 g/m²) . The film 1 8 is then cohered to the substrate composite

24 by any suitable process known in the art.

The underlay 1 2 of both embodiments has a first face 26

comprised of the film 1 8 and a second face 28 comprised of the foam

20. In the preferred embodiment of the system 1 0, the second face 28 has a coefficient of friction greater than 0.8 between itself and the

subfloor 1 4, so that when the second face 28 is installed against the

subfloor 1 4, the friction between the subfloor 1 4 and the second face

28 prevents slipping and bunching relative to each other. While the

coefficient of friction of the second face 28 is greater than 0.8

between itself and the subfloor 1 4, in the preferred embodiment, the

material from which the subfloor 1 4 is made determines how high the

coefficient of friction of the second face 28 must be in order to

prevent slipping and bunching during installation .

In the preferred embodiment, the first face 26 has a

coefficient of friction between itself and the floating floor 1 6 less than

0.8, preferably in the range of about 0.4 to ON, and most preferably

about 0.6. The first face 26 must be relatively slippery, compared to

the second face 28, since installation of the floating floor 1 6 generally

consists of sliding the floating floor 1 6 over the first face 26 during

the installation process. The relatively low coefficient of friction of

the first face 26 in contact with the underside of the floating floor 1 6

prevents bunching or tearing of the underlay 1 2 when the floating

floor 1 6 is slid into place during installation .

In the preferred embodiment, the film 1 8 has a tensile

strength of greater than about 2500 psi ( 1 76 kg/cm²) in the machine direction, an elongation of less than 250% in the machine direction, a

tensile strength of greater than about 2500 psi ( 1 76 kg/cm²) in the

cross-machine direction and elongation of less than 250% in the

cross-machine direction. In the most preferred embodiment, the film

has a tensile strength of about 31 58 psi (222.5 kg/cm²) in the

machine direction, an elongation of less than 222% in the machine

direction, a tensile strength of about 2874 psi (202.1 kg/cm²) in the

cross-machine direction, and a elongation of lass than 231 % in the

cross-machine direction .

In the preferred method of installation of the present

inventive system, the subfloor 1 4 is first prepared by sweeping or

vacuuming in order to remove dirt or other foreign articles that may

tear the underlay 1 2, making it difficult for the underlay 1 2 to grip the

subfloor 1 4, or otherwise cause irregularities in the underlay 1 2 after

installation.

The underlay 1 2 is then laid over the subfloor 1 4 so that

the second face 28 is against the subfloor 1 4. It will be understood

by those in the art that the underlay 1 2 may be manufactured to any

desired dimensions. In the most preferred method, 30 inch (0.76 cm)

wide sheets of the underlay 1 2 are laid on the subfloor 1 4 so that

their edges abut each other. Seams 30, defined by abutting sheets of underlay 1 2, are then sealed by tape 32 in order to create a moisture

impermeable underlay 1 2. As is mentioned above, if the seams 30

are not taped, moisture may travel horizontally through the foam 20

and migrate up through the seams 30. In the preferred method, the

tape 32 is 2 inches (5 cm) packing tape having a water insoluble

adhesive such as is readily available from the 3M Corporation . It will

be understood by those in the art that any suitable sealant may be

used to fix the sheets of underlay 1 2 in relation to each other and

prevent moisture from the subfloor 1 4 from seeping up through the

seams 30.

When installing the floating floor system 1 0, the underlay

1 2 is laid on the subfloor 1 4 so as to leave the underlay edge 34

riding up a wall 36, as shown in Fig . 2. The floating floor 1 6 is then

slid across the second face 26 of the underlay 1 2 to be located at

any desired position. The underlay edge 34 may be thereafter

trimmed to the room size or concealed by a strip of moulding (not

shown) .

From the above disclosure of the detailed description of

the present invention and the preceding summary of the preferred

embodiment, those skilled in the art will comprehend the various

modifications to which the present invention is susceptible. Therefore, I desire to be limited only by the scope of the following

claims and equivalents thereof.

I claim:

Claims

1 . A floating floor underlay for placement between a

subfloor and a floating floor, comprising :

an open-celled foam sheet consisting of latex,

polyvinylchloride or polyurethane; and

a moisture impermeable polymer film cohered to said

foam sheet.

2. The underlay of claim 1 , wherein said foam is cast to

said film.

3. The underlay of claim 1 , wherein said foam sheet has a

coefficient of friction between itself and the subfloor of greater than

0.8.

4. The underlay of claim 1 , wherein said film has a

coefficient of friction between itself and the floating floor of less than

ON.

5. The underlay of claim 4, wherein said film has a

coefficient of friction between itself and the floating floor of about

0.6.

6. The underlay of claim 1, wherein said foam has a density

greater than 10 lb/ft³ (160.2 kg/m³).

7. The underlay of claim 1, wherein said foam has a

thickness in the range of about 0.045 inches (0.11 cm) to about 0.1

inches (0.25 cm).

8. The underlay of claim 1, comprising a carrier to which

said foam is cohered.

9. A floating floor underlay for placement between a

floating floor and a subfloor, comprising:

an open-celled foam having a coefficient of friction

between itself and the subfloor greater than 0.8, a density greater

than 10 lb/ft³ (160.2 kg/m³), and a thickness in the range of about

0.045 inches (0.11 cm) to about 0.1 inches (0.25 cm), said foam

consisting of latex, polyvinylchloride or polyurethane, and

a moisture impermeable polymer film to which said foam

is cast, said film having a coefficient of friction between itself and the

floating floor in the range of about 0.4 to about ON.

1 0. A floating floor underlay for placement between a

subfloor and a floating floor, comprising :

a moisture impermeable polyvinylchloride film having a

coefficient of friction between itself and the floating floor of about

0.6; and

an open-celled foam sheet cast to said film, said foam

having a coefficient of friction between itself and the subfloor of

greater than 0.8, wherein said foam sheet consists of latex,

polyvinylchloride, or polyurethane having a density greater than 1 0

lb/ft³ ( 1 60.2 kg/m³) and a thickness of about 0.075 inches (0. 1 9 cm)

1 1 . A floating floor underlay for placement between a

floating floor and a subfloor, comprising :

a moisture impermeable polyvinylchloride film having a

coefficient of friction between itself and the floating floor of about

0.6; and

an open-celled foam sheet cast to said film, said foam

having a coefficient of friction between itself and the subfloor greater

than 0.8, wherein said foam sheet consists of latex, polyvinylchloride,

or polyurethane having a density greater than 1 0 lb/ft³ ( 1 60.2 kg/m³),

and a thickness of about 0.075 inches (0.1 9 cm); and

a textile carrier cohered to said foam sheet.

1 2. A floating floor system for installation over a subfloor,

comprising :

an underlay located against the subfloor, said underlay

having an open-celled foam consisting of latex, polyvinylchloride or

polyurethane cohered to a moisture impermeable polymer film,

wherein said foam is located against the subfloor; and

a floating floor located against said film.

1 3. The system of claim 1 2, wherein said foam is cast to

said film.

1 4. The system of claim 1 2, wherein said foam has a

coefficient of friction between itself and the subfloor of greater than

0.8.

1 5. The system of claim 1 2, wherein said film has a

coefficient of friction between itself and said floating floor in the

range of about 0.4 to about ON .

16. The system of claim 15, wherein said film has a

coefficient of friction between itself and said floating floor of about

0.6

17. The system of claim 12, wherein said foam has a density

greater than 10 lb/ft³ (160.2 kg/m³).

18. The system of claim 12, wherein said foam has a

thickness in the range of about 0.045 inches (0.11 cm) to about 0.1

inches (0.25 cm).

19. The system of claim 12, comprising a carrier to which

said foam is cohered.

20. A floating floor system for installation over a subfloor,

comprising :

an underlay located against the subfloor, said underlay

having an open-celled foam with a coefficient of friction between

itself and the subfloor greater than 0.8, a density greater than 1 0

lb/ft³ ( 1 60.2 kg/m³) , and a thickness in the range of about 0.045

inches (0.1 1 cm) to about 0. 1 inches (0.25 cm) , said foam consisting

of latex, polyvinylchloride or polyurethane cast to a moisture

impermeable polymer film, wherein said foam is located against the

subfloor; and

a floating floor located against said film, wherein said

film has a coefficient of friction between itself and said floating floor

in the range of about 0.4 to about ON.

21 . A floating floor system for installation over a subfloor,

comprising :

an underlay located against the subfloor, said underlay

having an open-celled foam with a coefficient of friction between

itself and the subfloor greater than 0.8, a density greater than 1 0

lb/ft³ ( 1 60.2 kg/m³), and a thickness of about 0.075 inches (0. 1 9

cm), said foam consisting of latex, polyvinylchloride or polyurethane

cast to a moisture impermeable polymer film, wherein said foam is

located against the subfloor; and

a floating floor located against said film, wherein said

film has a coefficient of friction between itself and said floating floor

of about 0.6.

22. A floating floor system for installation over a subfloor,

comprising :

an underlay located against the subfloor, said underlay

having an open-celled foam cohered to a carrier and having a

coefficient of friction between itself and the subfloor greater than 0.8,

a density greater than 1 0 lb/ft³ ( 1 60.2 kg/m³) , and a thickness of

about 0.075 inches (0. 1 9 cm) , said foam consisting of latex,

polyvinylchloride or polyurethane cast to a moisture impermeable

polymer film, wherein said foam is located against the subfloor; and

a floating floor located against said film, wherein said

film has a coefficient of friction between itself and said floating floor

of about 0.6.

23. A method for installing a floating floor over a subfloor,

comprising the steps of :

laying a sheet of underlay over the subfloor, said

underlay having first and second faces, said first face having a

coefficient of friction greater than 0.8 between itself and the subfloor

and said second face, wherein said first face is adjacent the subfloor;

locating the floating floor adjacent the second face of the

underlay, wherein the second face has a coefficient of friction

between itself and the floating floor in the range of about 0.4 to

about ON.

24. The method of claim 23, comprising the step of:

trimming said underlay to desired dimensions.

25. The method of claim 23, comprising the steps of:

laying plural sheets of said underlay over the subfloor;

abutting adjacent sheets of said underlay, forming seams

therebetween; and

sealing said seams with moisture impermeable tape.