LAMINATED FOAM COMPOSITE BACKER BOARD FOR WET SPACE CONSTRUCTION

Abstract

A composite backer board for wet space construction is disclosed, along with a method of producing the backer board. The board includes a rigid foam core of a suitable thickness for wet space construction. A first fabric layer is fixed to at least one face of the rigid foam core with a polymeric adhesive. A first polymer layer is on the first fabric layer in which the polymer layer is dimensionally stable parallel to the face of the rigid foam core. A second fabric layer is on the first polymer layer opposite the first fabric layer and forms a first face that is amenable to thin set mortar and related compositions in wet space construction.

Claims

1. A composite backer board for wet space construction, said board comprising: a rigid foam core of a suitable thickness for wet space construction; a first fabric layer fixed to at least one face of said rigid foam core with a polymeric adhesive; a first polymer layer on said first fabric layer in which the polymer layer is dimensionally stable parallel to said face of said rigid foam core; and a second fabric layer on said first polymer layer opposite said first fabric layer and forming a first face that is amenable to thin set mortar and related compositions in wet space construction.

2. A composite backer board according to claim 1 and further comprising: a third fabric layer fixed with a polymeric adhesive to the opposite face of said rigid foam core from said first and second fabric layers; a second polymer layer on said third fabric layer in which the polymer layer is dimensionally stable parallel to said face of said rigid foam core; and a fourth fabric layer on said second polymer layer opposite said third fabric layer and forming a second face that is amenable to thin set mortar and related compositions in wet space construction.

3. A composite backer board according to claim 1 wherein said polymer layer is selected from the group consisting of thermoplastic material and thermosetting material.

4. A composite backer board according to claim 1 wherein said foam core layer is comprised of foam selected from the group consisting of extruded polystyrene (XPS), expanded polystyrene (EPS), polyethylene-terephthalate (PET), or polyisocyanurate (ISO).

5. A composite backer board according to claim 1 wherein said foam core layer comprises extruded polystyrene foam.

6. A composite backer board according to claim 1 wherein said foam composite backer board has a water vapor permeability of 0.5 perms or less measured according to ASTM E96 Procedure E (100° F., 90% RH) for ½ inch thick of board.

7. A composite backer board according to claim 1 wherein said composite backer board has a flexural strength of at least 250 PSI when measured according to ASTM C947.

8. A composite backer board according to claim 1 wherein said polymer layer has a modulus of elasticity and tensile strength that when combined with the thickness of the facer, provides the necessary flexural stiffness and strength for tile applications.

9. A composite backer board according to claim 8 wherein said polymer layer has a modulus of elasticity of at least 200,00 PSI and a tensile strength of at least 25 lb./inch.

10. A composite backer board according to claim 1 wherein said first fabric layer has a thickness sufficient to prevent the adhesive from entirely saturating the fabric's bonding sites.

11. A composite backer board according to claim 10 wherein said first fabric layer has a thickness that defines a weight of between about 0.75 and 2.25 osy.

12. A composite backer board according to claim 1 wherein said fabric is selected from the group consisting of a polyolefin-based scrim or knitted, woven, or nonwoven fabric.

13. A composite backer board for wet space construction, said board comprising: a rigid foam core of a suitable thickness for wet space construction; a first facer layer fixed to one face of said rigid foam core with a polymeric adhesive; and a second facer layer fixed to one face of said rigid foam core opposite said first facer layer with a polymeric adhesive.

14. A composite backer board according to claim 13, wherein said first and second facer layers further comprise: a dimensionally stable polymeric film; a first fabric fixed to at least one face of said polymeric film; and a second fabric fixed to said polymeric film opposite said first fabric.

15. A composite backer board according to claim 14 wherein at least one of said fabrics is bondable to thin set mortar.

16. A composite backer board according to claim 13 wherein said foam core is comprised of foam selected from the group consisting of extruded polystyrene (XPS), expanded polystyrene (EPS), polyethylene-terephthalate (PET), or polyisocyanurate (ISO).

17. A foam backer board according to claim 12 wherein said foam comprises extruded polystyrene.

18. A method of making a composite board that is particularly suited for thin set mortar and wet space construction, the method comprising: feeding two fabric layers with a melted polymer there between to a pair of nip rollers to join the fabric layers and the melted polymer; and curing the melted polymer between the two fabric layers to produce a dimensionally stable composite facer structure.

19. A method according to claim 18 further comprising applying a first composite facer structure to one face of a foam core board to add strength and rigidity to the foam core board and to provide the foam core board with a surface that is bondable to thin set mortar and related wet space adhesive and construction materials.

20. A method according to claim 18 further comprising applying a second composite facer structure to one face of a foam core board opposite said first composite facer structure.

21. A method according to claim 18 wherein said melted polymer is dimensionally stable upon curing.

22. A method of bonding a dimensionally stable polymeric film with little to no mechanical bonding sites to polymer foam, the method comprising: fixing a fabric layer to said dimensionally stable polymeric film with a polymeric adhesive or resin; and fixing said fabric layer to said polymer foam with said polymeric adhesive or resin opposite said dimensionally stable polymeric film.

23. A method according to claim 22 wherein said fabric has a thickness sufficient to prevent adhesive used to attach said fabric to said dimensionally stable polymeric film from entirely saturating said fabric's bonding sites but less than a thickness that decreases said fabric's lateral stability.

24. A method according to claim 22 wherein said fabric has a porosity sufficient to provide mechanical bonding sites for said adhesive to adhere to but less than a porosity that decreases said fabric's lateral stability.

25. A method according to claim 22 wherein said polymeric adhesive layer has a thickness sufficient to bond said fabric layer to said dimensionally stable polymeric film but less than a thickness that would exceed the thickness of said fabric.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] FIG. 1 is a perspective view of a wall shower assembly according to the invention.

[0035] FIG. 2 is a perspective view of shower surface application to the wall.

[0036] FIG. 3 is perspective view of the foam core alone.

[0037] FIG. 4A is a perspective view of the foam core and the front-facing composite layer.

[0038] FIG. 4B is a perspective view of the foam core and the rear-facing composite layer.

[0039] FIG. 5 is a cross-sectional view of the foam composite backer board layers.

[0040] FIG. 6 is a schematic view of the facer layer manufacturing process.

DETAILED DESCRIPTION

[0041] FIG. 1 is a perspective view of a wall shower assembly or wet space according to the present invention. FIG. 1 shows the foam composite backer board (10) used in the construction of a shower wet space. Although the foam composite backer board (10) is useful in wet space construction other than shower assemblies, FIG. 1 gives helpful context for how the foam composite backer board (10) is used.

[0042] The foam composite backer board (10) is substantially waterproof. Because the foam composite backer board (10) is substantially waterproof, the foam composite backer board (10) can be fastened directly to (for example) a framed wall substrate (13) or a flooring substrate (18) with typical backer board screws or galvanized roofing nails (11) without the need for washers. As illustrated in FIG. 1, the foam composite backer board (10) may also be fastened directly to a substrate (13, 18) without the need to apply an additional waterproof membrane between the backer board (10) and the tile covering (12). The backer board (10) may be applied in this manner to any wet space substrate and is not limited to vertical wall substrate application.

[0043] The backer board (10) is of a suitable thickness for wet space construction (e.g., ¼-2 inch) and yet provides the necessary rigidity and tensile, flexural, and shear strength for tile application.

[0044] The extent to which a wall material thickness is suitable is, of course, the choice of the builder or owner. Conventionally, however, the most common size of backer board (to which foam backer board for wet space is most closely related) is 3 feet wide by 5 feet long by ¼-⅝ inch thick. Conventional backer board of this size weighs about 2-3 pounds per square foot, but the foam backer board will typically weigh between 0.35-0.6 pounds per square foot.

[0045] Accordingly, ¼, ½, and ⅝ inch are among the most common thicknesses for the backer board of the present invention.

[0046] The backer board (10; FIG. 1) is easily cut to allow for openings for plumbing fixtures such as a faucet opening (15), and a shower head (14). FIG. 1 also illustrates a shower drain (17).

[0047] A wet space surface (12), such as tile or stone, is applied to the backer board (10).

[0048] A shower base (16) may be used in conjunction with the backer board (10) to simplify shower construction. When appropriate, a waterproof membrane (19) may be applied to the shower base, corners, and perpendicular edges to support waterproof construction.

[0049] FIG. 1 illustrates a curb style shower, but this is illustrative rather than limiting of the invention.

[0050] FIG. 2 is a perspective view of the application of a shower surface (12), such as tile or stone, to the backer board (10). The backer board (10) is bondable to thin set mortar (20), which allows shower surface tile (12) to be applied to the backer board (10) without additional anchors and sealants. FIG. 2 shows the application of thin set mortar (20) directly to one face of the backer board (10) and the application of shower surface tile (12) to one face of the backer board (10) using the thin set mortar (20).

[0051] FIG. 3 is a perspective view of the foam core (21) alone. In the exemplary embodiment, the foam core (21) consists of extruded polystyrene (XPS) foam. In alternative embodiments, the foam core (21) may consist of expanded polystyrene (EPS), polyethylene-terephthalate (PET), or polyisocyanurate (ISO) foam.

[0052] FIG. 4A is a perspective view of the foam core (21) and the front-facing composite facer layer (22) of the backer board (10). FIG. 4B is a perspective view of the foam core (21) and the rear-facing composite facer layer (23) of the backer board (10).

[0053] In the illustrated embodiment, a front-facing composite facer layer (22) is fixed directly to one face of the rigid foam core (21) with a polymeric adhesive (30, e.g., FIG. 5). A rear-facing composite facer layer (23) is fixed directly to another face of the rigid foam core (21) with a polymeric adhesive (34, e.g., FIG. 5) opposite the front-facing composite facer layer (22). At least one of the outer fabrics (33 or 37) is bondable to thin set mortar.

[0054] FIG. 5 is a cross-sectional view of the backer board (10) and shows greater detail of the facer layers (22, 23) illustrated in 4A and 4B.

[0055] FIG. 5 shows that the foam composite backer board (10) is made up of several layers affixed to each other. A first fabric layer (31) is affixed to at least one face of the rigid foam core (21) with a polymeric adhesive (30). A first dimensionally stable polymeric film (32) is affixed to the first fabric layer (31), parallel to the face of the rigid foam core (21), providing sufficient flexural strength for wet space construction (e.g., at least 250 PSI when measured according to ASTM C947). A second fabric layer (33) is affixed to the first dimensionally polymeric film (32) opposite the first fabric layer (31). The first fabric layer (31) comprises the inner fabric layer, whereas the second fabric layer (33) comprises the outer fabric layer of the front-facing composite layer (22).

[0056] A third fabric layer (35) is affixed to at least one face of the rigid foam core (21) with a polymeric adhesive (34). A second dimensionally stable polymeric film (36) is affixed to the third fabric layer (35), parallel to the face of the rigid foam core (21). A fourth fabric layer (37) is affixed to the dimensionally stable polymeric film (36) opposite the third fabric layer (35). The third fabric layer (35) comprises the inner fabric layer, whereas the fourth fabric layer (37) comprises the outer fabric layer of the rear-facing composite layer (23).

[0057] At least one outer fabric layer (33 or 37) is bondable to thin set mortar (20) and related compositions in wet space construction.

[0058] The inner fabric layer (31 or 35) is thick enough to prevent the adhesive from entirely saturating the fabric's bonding sites but thin enough to maintain the fabric's lateral stability as part of the composite. The inner fabric layer (31 or 35) may consist of a scrim or knitted, woven, or nonwoven fabric, e.g., a 0.75 osy (ounce per square yard)-2.25 osy polypropylene spun bond possessing a porosity sufficient to provide mechanical bonding sites for the adhesive (e.g., dry, fibrous microstructure).

[0059] FIG. 6 is a schematic view of the manufacturing process of one of the facer layers (22 or 23).

[0060] As illustrated in FIG. 6, a composite facer layer (22 or 23) is formed by feeding two fabric layers (31 and 33 or 35 and 37) and a melted polymer (32 or 36) between the two fabrics (31 and 33 or 35 and 37) to a pair of nip rollers (41). The nip rollers (41) join the fabrics (31 and 33 or 35 and 37) and the melted polymer (32 or 36). The melted polymer (32 or 36) is then cured to produce a dimensionally stable composite facer structure (22 or 23). Depending upon the polymer composition, curing can include exposure to light or to heat, or simply allowing the polymer to cure at room temperature for an appropriate time interval.

[0061] The resulting composite facer structure (22 or 23) consists of a dimensionally stable polymeric film (32 or 36), an outer fabric layer (33 or 37) fixed to at least one face of the dimensionally stable polymeric film (32 or 36), and an inner fabric layer (31 or 35) fixed to the dimensionally stable polymeric film (32 or 36) opposite the outer fabric layer (33 or 37).

[0062] The dimensionally stable polymeric film (32 or 36) may be a thermoplastic or thermosetting material. The dimensionally stable polymeric film (32 or 36) also has a relatively high modulus (e.g., 200,000 psi or greater) and a tensile strength of at least 25 lb./inch.

[0063] Those of skill in the art will recognize that a higher modulus polymer can be applied in a thinner layer than a lower modulus polymer in order to obtain the same effect. Thus, for oriented polystyrene the lower limit is typically about 0.003 inch thickness (three mil), with an upper limit of about 0.015 inch (15 mil). Applying a thicker layer of other types of materials is possible to gain the same effect, but can complicate the manufacturing process or add to the cost of materials or both.

[0064] When fixed to either face of the foam core (21), the composite facer structure (22 or 23) adds flexural strength and rigidity to the foam core board (21). The composite facer structure (22 or 23) further provides the foam core board (10) with a surface that is bondable to thin set mortar (20) and related wet space adhesive and construction materials. As the skilled person recognizes, if a backer board (e.g., the composite) has an insufficient or inappropriately low flexural strength, a resulting finished wall built using the board can exhibit cracks, broken grout or delaminated tile under stresses that would otherwise be considered moderate.

[0065] In the specification and drawings, typical embodiments of the invention have been disclosed. The present invention is not limited to such exemplary embodiments. The use of the term “and/or” includes any and all combinations of one or more of the associated listed items. The figures are schematic representations and so are not necessarily drawn to scale. Unless otherwise noted, specific terms have been used in a generic and descriptive sense and not for purposes of limitation.