NL2032743B1

NL2032743B1 - Subfloor panel and subfloor panel system

Info

Publication number: NL2032743B1
Application number: NL2032743A
Authority: NL
Inventors: Lingg Edwin
Original assignee: Li&Co Ag
Priority date: 2022-08-12
Filing date: 2022-08-12
Publication date: 2024-02-16
Also published as: WO2024032970A1

Abstract

The invention relates to a subfloor panel for use beneath a decorative floor covering, in particular a floating decorative floor covering composed of a plurality of decorative floor panels. The invention also relates to a subfloor panel system comprising a plurality of said subfloor panels according to the invention for use beneath a decorative floor covering.

Description

Subfloor panel and subfloor panel system

The invention relates to a subfloor panel for use beneath a decorative floor covering, in particular a floating decorative floor covering composed of a plurality of decorative floor panels. The invention also relates to a subfloor panel system comprising a plurality of said subfloor panels according to the invention.

The demand for rigid decorative flooring materials such as ceramic and masonry tiles and decorative floor panel has grown over recent years. These products are, among other qualities, durable, easy to maintain, and attractive. However, despite their numerous desirable qualities, these materials typically exhibit insufficient acoustic properties with regard to structure-borne sound transmission. Specifically, the noises generated by footfalls or other periodic impacts are readily transmitted to and beyond an underlying concrete or wooden construction floor.

Therefore, often an underlayment or subfloor is applied in between the construction floor and the decorative floor covering with the purpose to provide sound abatement for a room and/or to provide a moisture barrier between the construction floor and the decorative floor covering. An example of such a subfloor is a bulky roll of foamed polyethylene, polyurethane, polystyrene and polypropylene. These rolls typically have a standard width, wherein during installation the foam is unrolled and positioned onto the construction floor. Adjacent foam layer are typically connected by an adhesive tape. However, this known method is considered as rather impractical, laborious and time consuming. Moreover, the acoustic properties of these subfloors typically deteriorate in the course of time during the constant compression of the foam which affects the sound absorption capacity of these subfloors.

It is therefore a first object of the present invention to provide an improved subfloor system, in particular improved subfloor panel. it is therefore a second object of the present invention to provide a more practical subfloor system, in particular a more practical subfloor panel.

it is therefore a third object of the present invention to provide an improved subfloor panel which allows relatively easy and fast installation of a subfloor. it is therefore a fourth object of the present invention to provide an improved subfloor panel having relatively durable acoustic properties.

At least one of these objects can be achieved by providing a subfloor panel according to the preamble, comprising: - atop layer having a top surface and a bottom surface, - a bottom layer having a top surface and a bottom surface, - the top surface of the bottom layer being adhered to the bottom surface of the top layer such that the bottom layer is offset from the top layer in a direction of length and/or width, thereby leaving both the top surface of a marginal end portion of the bottom layer and the bottom surface of a marginal end portion of the top layer exposed, wherein a length and/or a width of the bottom layer is preferably less than a length and/or a width of the top layer, creating an optional gap between the bottom layer of the subfloor panel and a bottom layer of an adjacent subfloor panel, and wherein the top layer comprises: - at a first top layer edge comprising a first coupling profile, and - at a second top layer edge, preferably located opposite to the first top layer edge, comprising a second coupling profile being designed to engage interlockingly with said first coupling profile of the top layer of an adjacent subfloor panel in horizontal direction and/or vertical direction.

The subfloor panel according to the invention has a plurality of advantages.

Subfloor panels are more practical to handle due to the limited size and weight compared to traditional foam rolls. Moreover, since the top layer comprises coupling profiles, adjacent subfloor panels can be interconnected without necessarily using tape and/or mechanical fastening means such as nails (which would affect the acoustic properties). This typically leads to a constant height of the subfloor while preserving the acoustic properties of the subfloor panels. Hence, the interconnectable subfloor panels are designed to realize a floating subfloor. The offset orientation of the top layer and the bottom layer stabilizes the eventual subfloor as adjacent subfloor panels will also support each other. Preferably, the top layer is oversized compared to the bottom layer. This will result in a gap formed in between bottom layers of adjacent subfloor panels. These gaps allow the top layers of adjacent subfloor panels to be positioned relatively tight to each other and prevent unwanted gap formation in between top layers of adjacent panels.

Moreover these gaps facilitate water drainage.

The subfloor panel according to the invention preferably comprises a top layer being composed of a single material layer. The single material layer does not have a decorative upper surface and can (therefore) be optimized for its purpose to support a decorative floor covering. Preferably, the top surface of the top layer defines the upper surface of the subfloor panel. it may be preferred that at least one marginal portion, preferably all marginal portions are free of any adhesive. It is additionally or alternatively also imaginable that at least one marginal portion is provided with an adhesive, preferably a pressure-sensitive adhesive. Because of the nature of a pressure-sensitive, the subfloor panels are capable of being easily detached from one another without damaging the subfloor panels for ease of installation and/or replacement thereof.

Preferably, said exposed adhesive (if applied) on the marginal portion(s) are initially covered by a removable release film. This is typically a flexible sheet, preferably corresponding in size and shape to the marginal portion(s). It will be appreciated by those skilled in the art, however, that the size and shape of the release film may be varied. The release film may be made, for example, from any known suitable release material, such as a silicone coated paper, a plastic sheet, a polymer film, or other material that enables the release film to be quickly and easily removed from the adhesive surface during the installation of the subfloor panel.

Preferably, the top layer is, directly or indirectly, adhered to the bottom layer. Any suitable adhesive, such as a hot melt adhesive (thermoplastic adhesive), a pressure sensitive adhesive, or a structural and/or reactive adhesive, can be used.

However, it is typically preferred to apply a thermoplastic adhesive, such as polyvinyl acetate, for this purpose. This latter allows easy (and clean) separation of the bottom layer and the top layer upon heating above a threshold temperature, such as 80 degrees Celsius. This facilitates recycling of the bottom layer and top layer. It is imaginable that at least one intermediate material layer (other than an adhesive layer) is present in between the bottom layer and the top layer. It is imaginable that the top layer is fused to the bottom layer, without using an additional adhesive. This latter can e.g. be realized by including a thermoplastic material in both the top layer and bottom layer which can be fused during a heating step.

The bottom layer is preferably composed of a single material layer. The material composition of the bottom layer may be identical to the material composition of the top layer. lt is also imaginable that the material composition and/or properties of the bottom layer are different from the material composition and/or properties of the top layer. Preferably, at least a part of the bottom surface of the bottom layer defines the bottom surface of the subfloor panel.

Itis imaginable that at least a part of the bottom surface of the bottom layer is covered by a backing layer, such as a cork layer and/or a foamed layer. Preferably, said backing layer is at least partially composed of at least one material chosen from the group consisting of a: preferably low density, foamed layer of ethylene- vinyl acetate (EVA), irradiation-crosslinked polyethylene (IXPE), expanded polypropylene (XPP), expanded polystyrene (XPS), a non-woven material and/or a woven material, preferably with fibres, such as made from natural fibres, like hemp or cork, and/or a recycled and/or recyclable (thermoplastic) material such as PET.

The backing layer is often applied to improve the acoustic panel properties and/or to provide more comfort to the subfloor panel to improve the user experience. it is imaginable that the top layer and/or the bottom layer is at least partially composed of at least one material chosen from the group consisting of: bamboo, hemp, wood, wood fibres, MDF, LDF, HDF, and plyboard. lt is also, additionally or alternatively, imaginable that the top layer and/or the bottom layer is at least partially composed of at least one material chosen from the group consisting of: mineral material, like magnesium oxide, gypsum, concrete, clay, talc, and/or calcium carbonate. It is also, additionally or alternatively, imaginable the top layer and/or the bottom layer is at least partially composed of at least one polymer material, preferably at least one thermoplastic material, more preferably at least one thermoplastic material is chosen from the group consisting of: PVC, PET, PP,

PS, thermoplastic polyurethane (TPU), PE, in particular MDPE and/or HDPE; and combinations thereof. Thermoplastic material may be used in foamed state and/or unfoamed state. Preferably, the bottom layer and/or the top layer is/are rigid (composed of a rigid material) or semi-flexible. 5

Preferably, the top layer and/or the bottom layer is at least partially composed a mixture of virgin and recycled polymer material. Preferably, at least a fraction of the polymer used may be formed by recycled thermoplastic, such a recycled PVC or recycled PU. It is conceivable that a mix of virgin and recycled thermoplastic material is used to compose at least a part of the core

The top layer and/or the bottom layer is/are at least partially composed of a water- resistant material. Such a material, of which examples are included in the lists above, make the top layer and/or the bottom layer unsusceptible for swelling, shrinking, and/or warping upon wettening.

Preferably, the first coupling profile and the second coupling profile are configured such that two of such subfloor panels can be coupled to each other by means of a turning movement and/or by means of a vertical movement.

It is often preferred that the panel comprises at least one third coupling profile and at least one fourth coupling profile located respectively at a third top layer edge and a fourth top layer edge. Preferably, the third coupling profile and the fourth coupling profile are configured such that two of such panels can be coupled to each other by means of a turning movement.

In a preferred embodiment, the first coupling profile and/or the third coupling profile comprises: an upward tongue, at least one upward flank lying at a distance from the upward tongue, an upward groove formed in between the upward tongue and the upward flank wherein the upward groove is adapted to receive at least a part of a downward tongue of a second coupling profile of an adjacent panel, and at least one first locking element, preferably provided at a distant side of the upward tongue facing away from the upward flank, and wherein the second coupling profile and/or the fourth coupling profile comprises: a first downward tongue, at least one first downward flank lying at a distance from the downward tongue, a first downward groove formed in between the downward tongue and the downward flank, wherein the downward groove is adapted to receive at least a part of an upward tongue of a first coupling profile of an adjacent panel, and at least one second locking element adapted for co-action with a first locking element of an adjacent panel, said second locking element preferably being provided at the downward flank.

Preferably, the first locking element comprises a bulge and/or a recess, and wherein the second locking element comprises a bulge and/or a recess. The bulge is commonly adapted to be at least partially received in the recess of an adjacent coupled panel for the purpose of realizing a locked coupling, preferably a vertically locked coupling. it is also conceivable that the first locking element and the second locking are not formed by a bulge-recess combination, but by another combination of co-acting profiled surfaces and/or high-friction contact surfaces.

In the abovementioned embodiment, it is imaginable that the first coupling profile (and/or third coupling profile) and the second coupling profile (and/or fourth coupling profile) are configured such that in coupled condition a pretension is existing, which forces coupled panels at the respective edges towards each other, wherein this preferably is performed by applying overlapping contours of the first coupling profile (and/or third coupling profile) and the second coupling profile (and/or fourth coupling profile), in particular overlapping contours of downward tongue and the upward groove and/or overlapping contours of the upward tongue and the downward groove, and wherein the first coupling profile (and/or third coupling profile) and the second coupling profile (and/or fourth coupling profile) are configured such that the two of such panels can be coupled to each other by means of a fold-down movement and/or a vertical movement, such that, in coupled condition, wherein, in coupled condition, at least a part of the downward tongue of the second coupling profile (and/or fourth coupling profile) is inserted in the upward groove of the first coupling profile (and/or third coupling profile), such that the downward tongue is clamped by the first coupling profile (and/or third coupling profile) and/or the upward tongue is clamped by the second coupling profile (and/or fourth coupling profile). ft is imaginable that the first coupling profile is configured to co-act with the second coupling profile as well as with the fourth coupling profile, and that the third coupling profile is also configured to co-act with the second coupling profile as well as with the fourth coupling profile. It is imaginable that the first coupling profile and the fourth coupling profile are identical.

In an embodiment of the panel according to the invention, the first coupling profile and/or the third coupling profile comprises: a sideward tongue extending in a direction substantially parallel to the upper side of the core, at least one second downward flank lying at a distance from the sideward tongue, and a second downward groove formed between the sideward tongue and the second downward flank, and wherein the second coupling profile and/or the fourth coupling profile comprises: a third groove configured for accommodating at least a part of the sideward tongue of the third coupling profile of an adjacent panel, said third groove being defined by an upper lip and a lower lip, wherein said lower lip is provided with an upward locking element, wherein the third coupling profile and the fourth coupling profile are configured such that two of such panels can be coupled to each other by means of a turning movement, wherein, in coupled condition: at least a part of the sideward tongue of a first panel is inserted into the third groove of an adjacent, second panel, and wherein at least a part of the upward locking element of said second panel is inserted into the second downward groove of said first panel it is conceivable that each first coupling profile and each third coupling profile is compatible — hence may co-act and interlock — with each second coupling profile and each fourth coupling profile. This may also apply in case interlocking coupling profiles do not have a completely complementary shape.

In a preferred embodiment, at least a coupling profile, and preferably all coupling profiles, is/are at least partially formed by the top layer and thus make integral part of the top layer.

The width of the (preferred) gap formed in between the lower layers of adjacent subfloor panels, in coupled condition, is preferably substantially constant along facing edges of lower layers of said coupled subfloor panels. Preferably, the width of the gap formed in between the lower layers of adjacent subfloor panels, in coupled condition, is situated in between 1 and 10 mm, preferably 1.5 and 5 mm. This prevents abutting of adjacent bottom layers and moreover could lead to sufficient water drainage properties. Preferably, at least a part of the gap formed between the lower layers of coupled panels extends in parallel and/or perpendicular to the longitudinal direction of the panel. The gap formed in between three interlocked subfloor panels is preferably substantially L-shaped.

Preferably, at least one, and preferably each marginal end portion, is substantially

L-shaped. This typically requires an offset orientation of the top layer with respect to the bottom layer in both length direction and width direction. Preferably, the length difference between the bottom layer and the top layer is situated in between 1 and 10 mm, preferably in between 1 and 6 mm. Preferably, the width difference between the bottom layer and the top layer is situated in between 1 and 10 mm, preferably in between 1 and 6 mm.

Preferably, a width and/or an offset distance of at least one marginal portion is situated in between 2 cm to 20 cm, preferably in between 5 cm to 10 cm.

The subfloor panel thickness in between 4 and 20 mm. It will be appreciated by a skilled person that other thickness may also be conceivable. Typically, the bottom layer and/or the top layer is/are substantially rectangularly and/or oblong shaped.

Preferably, an upper edge region of at least two edges, preferably all edges, of the top layer is proved with a bevel or other chamfer. These bevels and/or other chamfers may be small, and may for example have a bevel width of less than 0.5 mm. The application of these (micro)bevel may prevent undesired small, noticeable height differences and/or ridges in between adjacent panels.

The invention also relates to a floor system, comprising a plurality of coupled subfloor panels according to the invention.

The invention will be elucidated on the basis of non-limitative exemplary embodiments shown in the following figures, wherein, - figure 1a and 1b schematically show a panel according to the present invention, - figure 2 is a cross-sectional view indicated by section A-A' in figure 1a;

- figure 3 is a cross-sectional view indicated by section B-B’ in figure 1a; - figure 4a and 4b schematically show two panels in coupled condition according to the present invention.

Figure 1a and 1b schematically show a panel 1 according to the present invention.

Figure 1a shows the front view of a substantially rectangular panel 1. Figure 1b shows the rear view of a substantially rectangular panel 1. The panel 1 comprises an upper layer 2 and a lower layer 3. The lower layer 3 is shifted with respect to the upper layer 2. The upper layer 2 comprises a first pair of opposite edges, in particular a first edge 4 and a complementary second edge 5, located at the long lateral sides of the panel 1. The upper layer 2 also comprises a second pair of opposite edges, in particular a third edge 6 and a complementary fourth edge 7, located at the short lateral sides of the panel 1 in this exemplary embodiment. The upper layer 2 is exposed to the external environment. The upper layer 2 can be brought into contact with an underlayment on top of which a covering of decorative panels is applied. In another embodiment, the upper layer 2 is directly brought into contact with a covering of decorative panels. Cross-sections of lines A-A' and B-B’ are shown in figures 3 and 4.

Figure 2 is a cross-sectional view indicated by section A-A’ in figure 1a. In this cross-section, the shape of the complementary first edge 104 and second 105 edge are shown in detail. The first edge 104 comprises a sideward tongue 109 which is integrally connected to the upper layer 102 of the panel 100. By means of the vertical dashed line the border between the sideward tongue 109 and the upper layer 102 is visualised. A front region 109a of the sideward tongue 109 is provided with a rounded bottom surface 110. An outer end of the rounded bottom surface 110 adjoins an inclined locking surface 111. An opposite end of the rounded bottom surface 110 adjoins a bearing surface 112 making part of a back region 109b of the sideward tongue 109. The second edge 105 of the panel 100 comprises an upper lip 113 and a lower lip 114 defining a recess 115. Both lips 113, 114 are integrally connected to the upper layer 102 of the panel 100. By means of the vertical dashed line the border between the lips 113, 114 and the upper layer 102 is visualised. The width of the upper lip 113 is substantially smaller than the width of the lower lip 114.

The recess 115 has a shape which is complementary to the shape of the sideward tongue 109. More in particular, a top surface 116 of a back region 114a of the lower lip 114 has a (complementary) rounded shape, configured to co-act with the rounded front region 109a of the sideward tongue 109, while a front region 114b of the lower lip 114 is provided with a upwardly protruding shoulder 117, configured to co-act with the bearing surface 112 of the sideward tongue 109. A lower surface 118 of the upper lip 113 is inclined and corresponds to the locking surface 111 of the sideward tongue 109. Locking at the first edge 105 and the second edge 106 of adjacent panels 100 by insertion of the sideward tongue 109 of a panel 100 to be coupled into the recess 115, wherein said panel 100 is initially held in an inclined position. After insertion of the sideward tongue 109 into the recess, the panel 100 to be coupled will be pivoted (angled) in downward direction about an axis parallel to the first edge 104 until both panels 101 are positioned in the same — commonly horizontal — plane, wherein the locking surface 111 of the sideward tongue 109 will engage the locking surface of the upper lip 118, and wherein at least a bottom front part is accommodated substantially form-fittingly in the recess 115, and wherein the bearing surface 112 is supported by the shoulder 117. Locking at the first edge 104 and the second edge 105 leads to locking of the connected panels 100 in both horizontal direction and vertical direction. The angling down locking principle of the first and second edges 104, 105 is a relatively easy locking principle which facilitates mutual coupling of panels at these edges 104, 105 tremendously.

Figure 3 is a cross-sectional view indicated by section B-B’ in figure 1a. In this cross-section, the shape of the complementary third edge 106 and fourth 107 edge are shown in detail. The third edge 106 comprises an upward tongue 119, an upward flank 120 and an upward groove 121 formed between upward tongue 119 and upward flank 120. The upward tongue 119 is connected to the upper layer 102 by means of a bridge 122, which is preferably resilient to some extent. A side 119a of upward tongue 119 facing toward upward flank 120 extends in the direction of the normal N1 of the upper side 110 of the upper layer 102. The tangent R1 and the normal N1 of the upper side 110 of the upper layer 102 are thus directed toward each other (converging orientation), wherein the angle enclosed by R1 and N1 is preferably between 0 and 10 degrees in this exemplary embodiment. Due to the converging orientation of the upward flank 120 and the side 119a of the upward tongue 119 facing toward to the upward flank 120, the upward groove 122 is a closed groove, which is only accessible to a complementary counterpart by deformation of the upward tongue 119 and/or bridge 122. Another side 119b of upward tongue 119 facing toward upward flank 120 forms or may form an aligning edge enabling facilitated realization of a coupling to an adjacent floor panel 100. As shown, this side 119b functioning as aligning edge is directed away from the normal N1 of upper side 110 of the upper layer 102. An upper side 119d of upward tongue 119 does however extend in the direction of the normal N1 of the upper side

110 of the upper layer 102, and runs inclining downward in the direction of the side 119e of upward tongue 119 facing away from upward flank 120. This chamfering provides the option of giving the complementary fourth edge 107 a more robust and therefore stronger form.

A part of the side 119e of the upward tongue 119 facing away from upward flank 120 is oriented substantially vertically and is moreover provided with an outward bulge 123. A lower part 120a of upward flank 120 is oriented diagonally, while an upper part 120b of upward flank 120 is shown to be substantially vertical and forms a stop surface for fourth edge 107. In between the inclined part 120a and the substantially vertical part 120b of the upward flank an additional coupling element, in particular an additional bulge 124, is provided.

A lower wall part 1214 of upward groove 121 is oriented substantially horizontally in this exemplary embodiment.

The fourth edge 107 is substantially complementary to third edge 106. The fourth edge 107 comprises a downward tongue 125, a downward flank 126 and a downward groove 127 formed between downward tongue 125 and downward flank 126. The downward tongue 125 is connected to the upper layer 102 by means of a bridge 128, which is preferably resilient to some extent.

A side 125a of downward tongue 125 facing toward downward flank 126 lies in the direction of the normal N2 of the lower side 111 of the upper layer 102. This means that a tangent R2 of side 125a of downward tongue 125 and the normal of the lower side 111 of the upper layer 102 are mutually converging, wherein the angle enclosed by R2 and N2 is preferably between 0 and 10 degrees in this exemplary embodiment.

More preferably, the inclination of R1 is identical to the inclination of R2; hence, R1 and R2 are preferably parallel.

Due to the converging orientation of the downward flank 126 and the side 125a of the downward tongue

125 facing toward to the downward flank 126, the downward groove 127 is a closed groove, which is only accessible for the upward tongue 119 of an adjacent panel 100 by deformation of the downward tongue 125 and/or bridge 128, as a result of which the entrance of the downward groove can be widened (temporary). A side 125b of the downward tongue 125 facing away from downward flank 126 is diagonally oriented, but has a flatter orientation than the complementary side 120a of upward flank 120, whereby a gap (air space) will be formed in the coupled position, which will generally facilitate coupling between two floor panels 100. The inclining side 125b of downward tongue 125 also functions as aligning edge for the purpose of further facilitating coupling between two panels 100. Another side 125¢ facing away from downward flank 126 takes a substantially vertical form, though is provided with a small cavity 129 configured to co-act with the additional bulge 124 of another panel 100. A top part of the side 125c facing away from downward flank 126 forms a complementary stop surface for stop surface 120b of upward flank 120 (of an adjacent floor panel). Downward flank 126 is oriented substantially vertically and is provided with a recess 130 adapted to receive the outward bulge 123 of the upward tongue 119 (of an adjacent panel).

Figure 4a and 4b schematically show a front view of two coupled panels 10 according to the present invention. In figure 4a the panels 10 are coupled at the long lateral sides of the panels 10. In this figure the panel edges 6, 16, 106 and 7, 17, 107 of the upper layers 12 of the panels 10 are coupled at the long lateral side of the panels 10. Between the lower layers 13 of the panels 10 a gap 18 is formed in coupled condition of the panels 10. The gap 18 extends in the same direction as the extension direction of interacting coupling profiles of the panel edges in coupled condition. So, in this embodiment the gap 18 extends in parallel to the longitudinal direction of the coupled panels 10. The width of the gap 18 is substantially equal along the extension direction of interacting coupling profiles of the panel edges in coupled condition. So, in this embodiment the width of the gap 18 is substantially equal along the longitudinal direction.

In figure 4b the panels 10 are coupled along the short lateral sides of the panels 10. In this figure the panel edges 4, 14, 104 and 5, 15, 105 of the upper layers 12 of the panels 10 are coupled at the short lateral side of the panels 10. Between the lower layers 13 of the panels 10 a gap 18 is formed in coupled condition of the panels 10. The gap 18 extends in the same direction as the extension direction of interacting coupling profiles of the panel edges in coupled condition. So, in this embodiment the gap 18 extends perpendicularly to the longitudinal direction of the coupled panels 10. The width of the gap 18 is substantially equal along the extension direction of interacting coupling profiles of the panel edges in coupled condition. So, in this embodiment the width of the gap 18 is substantially equal along the transverse direction.

The above-described inventive concepts are illustrated by several illustrative embodiments. It is conceivable that individual inventive concepts may be applied without, in so doing, also applying other details of the described example. It is not necessary to elaborate on examples of all conceivable combinations of the above- described inventive concepts, as a person skilled in the art will understand numerous inventive concepts can be (re)combined in order to arrive at a specific application.

It will be apparent that the invention is not limited to the working examples shown and described herein, but that numerous variants are possible within the scope of the attached claims that will be obvious to a person skilled in the art.

The verb “comprise” and conjugations thereof used in this patent publication are understood to mean not only “comprise”, but are also understood to mean the phrases “contain”, “substantially consist of”, “formed by” and conjugations thereof.

Claims

Conclusions

1. An underlay panel for use under a decorative floor covering, in particular a floating decorative floor covering made from a plurality of decorative floor panels, comprising: - a top layer having a top surface and a bottom surface, - a bottom layer having a top surface and a bottom surface, - the top surface of the bottom layer is attached to the bottom surface of the top layer in such a way that the bottom layer is displaced with respect to the top layer in a longitudinal and/or width direction, whereby both the top surface of a marginal end part of the bottom layer and the bottom surface of a marginal end portion of the top layer exposed, wherein a length and/or a width of the bottom layer is less than a length and/or width of the top layer, forming an intermediate space between the bottom layer of the subfloor panel and a bottom layer of an adjacent underfloor panel, and wherein the top layer comprises: - on a first top layer edge comprising a first coupling profile, and - on a second top layer edge, preferably located opposite the first top layer edge, comprising a second coupling profile designed to engage in a locking manner with the aforementioned first coupling profile of the top layer of an adjacent subfloor panel in horizontal direction and/or vertical direction.

2. Subfloor panel according to claim 1, wherein the top layer is made of a single material layer.

3. Subfloor panel according to claim 1 or 2, wherein the top surface of the top layer defines the top surface of the underfloor panel.

4. Subfloor panel according to any one of the preceding claims, wherein at least one marginal part, preferably all marginal parts, are free of adhesive.

5. Subfloor panel according to any one of the preceding claims, wherein at least one marginal part is provided with an adhesive.

The underfloor panel of claim 5, wherein said adhesive is a pressure sensitive adhesive.

The subfloor panel of claim 6, wherein the panel further comprises a removable protective film that initially covers the pressure sensitive adhesive.

8. Subfloor panel according to any one of the preceding claims, wherein the top layer is attached, preferably directly, to the bottom layer.

9. Subfloor panel according to any one of the preceding claims, wherein the top layer is bonded to the bottom layer by a thermoplastic adhesive, preferably polyvinyl acetate.

10. Subfloor panel according to any one of the preceding claims, wherein the bottom layer is made of a single material layer.

11. Underfloor panel according to any one of the preceding claims, wherein at least a part of the bottom surface of the bottom layer defines the bottom surface of the underfloor panel.

12. Bottom panel according to any one of the preceding claims, wherein at least part of the bottom surface of the bottom layer is covered by a supporting layer, such as a cork layer and/or a foamed layer.

13. Underfloor panel according to claim 12, wherein the underlay is at least partially made of at least one material selected from the group consisting of: preferably low density, foamed layer of ethylene vinyl acetate (EVA), radiation cross-linked polyethylene (IXPE), expanded polypropylene (XPP), expanded polystyrene (XPS), a non-woven material and/or a woven material, preferably with fibers, such as made from natural fibers, such as hemp or cork, and/or a recycled and/or recyclable material! such as PET.

14. Bottom panel according to any one of the preceding claims, wherein the top layer and/or the bottom layer are at least partly made of at least one material selected from the group consisting of: bamboo, hemp, wood, wood fibers, MDF, LDF, HDF and plywood sheet.

15. Underfloor panel according to any one of the preceding claims, wherein the top layer and/or the bottom layer is at least partly made of at least one material selected from the group consisting of: mineral material, such as magnesium oxide, gypsum, concrete, clay, talc and/or calcium carbonate .

16. Underfloor panel according to any one of the preceding claims, wherein the top layer and/or the bottom layer is at least partly made of at least one polymer material, preferably at least one thermoplastic material, further preferably at least one thermoplastic material selected from the group consisting of : PVC, PET, PP, PS, thermoplastic polyurethane (TPU), PE, in particular MDPE and/or HDPE; and combinations thereof.

17. Subfloor panel according to any one of the preceding claims, wherein the top layer and/or the bottom layer is at least partly made of a mixture of new and recycled polymer material.

18. Subfloor panel according to any one of the preceding claims, wherein the top layer and/or the bottom layer is at least partly made of water-resistant material.

19. Subfloor panel according to any one of the preceding claims, wherein the marginal end parts are substantially L-shaped.

20. Underfloor panel according to any one of the preceding claims, wherein the first coupling profile comprises: e a first upward tongue, e at least one first upward flank located at a distance from the upward tongue, e a first upward groove formed between the first upward tongue and the first upward flank wherein the first upward groove is adapted to receive at least a portion of a second downward tongue of a second coupling profile of an adjacent panel, and e preferably at least one first locking element, more preferably provided on a remote side of the first upward tongue directed away from the upward flank, and wherein the second coupling profile comprises: es a second downward tongue, e at least one second downward flank spaced from the downward tongue, eo a second downward groove formed between the downward tongue and the downward flank, wherein the downward groove is adapted to receive at least part of an upward tongue of a first coupling profile of an adjacent panel, and preferably at least one second locking element, adapted to cooperate with a first locking element of an adjacent panel, wherein said second locking element is more preferably provided on the downward flank.

21. Underfloor panel according to claim 20, wherein the first coupling profile and the second coupling profile are designed such that two such panels can be coupled to each other by means of a rotating movement and/or by means of a vertical movement; and/or where, in the coupled condition of adjacent panels, the first coupling profile of the panel and the second coupling profile of an adjacent panel are arranged in such a way that two such panels can be moved by means of a rotating movement and/or by means of a vertical movement and/ or can be disconnected from each other by means of a horizontal movement.

22. Underfloor panel according to any one of the preceding claims, wherein the underside panel comprises at least one third coupling profile and at least one fourth coupling profile, respectively located on a third top layer edge and a fourth top layer edge, wherein the third coupling profile comprises: e a sideways tongue that extends in a direction substantially parallel to a plane defined by the panel and/or to the top of the core,

e at least one third downward flank located at a distance from the lateral tongue, and es a third downward groove formed between the lateral tongue and the third downward flank, wherein the third coupling profile and the fourth coupling profile are arranged in such a way that two such panels can be linked together by means of a rotating movement.

23. Subfloor panel according to claim 22, wherein the fourth coupling profile comprises a fourth groove that is adapted to receive at least a portion of the lateral tongue of the third coupling profile of an adjacent panel, said fourth groove being defined by an upper lip and a lower lip, wherein said lower lip is provided with an upward locking element, wherein, in coupled condition: at least a portion of the lateral tongue of a first panel is inserted into the fourth groove of an adjacent, second panel, and wherein at least a portion of the upward locking element of said second panel is inserted into the third downward groove of said first panel.

24. Underfloor panel according to claim 23, wherein a fourth locking element is provided on a remote side of the upward locking element facing away from the fourth groove, wherein said fourth locking element is designed to cooperate with a locking element of a complementary coupling profile, in particular a second locking element of a second coupling profile of another panel, in the coupled condition of said panels.

25. Underfloor panel according to any one of claims 22-24, wherein the first coupling profile and the fourth coupling profile are identical.

26. Underfloor panel according to any one of the preceding claims, wherein the width of the space formed between the bottom layers of adjacent underfloor panels, in coupled condition, is essentially constant along mutually facing edges of bottom layers of said coupled underfloor panels.

27. Underfloor panel according to any one of the preceding claims, wherein the width of the space formed between the bottom layers of adjacent underfloor panels, in coupled condition, is between 1 and 10 mm, preferably 1.5 and 5 mm.

28. Underfloor panel according to any one of the preceding claims, wherein at least part of the space formed between the lower layers of coupled panels extends parallel to the longitudinal direction of the panel.

29. Subfloor panel according to any one of the preceding claims, wherein at least part of the space formed between the lower layers of coupled panels extends perpendicular to the longitudinal direction of the panel.

30. Subfloor panel according to any one of the preceding claims, wherein the difference in length between the bottom layer and the top layer is between 1 and 10 mm, preferably between 1 and 6 mm.

31. Subfloor panel according to any one of the preceding claims, wherein the width difference between the bottom layer and the top layer is between 1 and 10 mm, preferably between 1 and 6 mm.

32. Underfloor panel according to any one of the preceding claims, wherein the underfloor panel thickness is between 4 and 20 mm.

33. Underfloor panel according to any one of the preceding claims, wherein the bottom layer and/or the top layer is/are substantially rectangular.

34. Underside panel according to any one of the preceding claims, wherein an upper edge area of at least two edges, preferably all edges, of the top layer is provided with a bevel or other rounding.

35. Subfloor panel according to any one of the preceding claims, wherein the width of each bevel or other rounding is less than 0.5 mm.

36. Panel according to any one of the preceding claims, wherein a width of at least one marginal part is between 2 cm and 20 cm, preferably between 5 cm and 10 cm.

37. Floor system, comprising a plurality of coupled subfloor panels according to any one of the preceding claims.