US20180110379A1

US20180110379A1 - Damage-resistant shower base and installation method

Info

Publication number: US20180110379A1
Application number: US15/790,271
Authority: US
Inventors: James Anthony Wadaga
Original assignee: Noble Co
Current assignee: Noble Co
Priority date: 2016-10-24
Filing date: 2017-10-23
Publication date: 2018-04-26
Also published as: US20200029747A1; WO2018080973A1

Abstract

A shower base includes a combination slab where a foam slab (tapered or flat or multi-tapered) having a sloped upper surface is covered with a thin deformation-resisting honeycomb slab (e.g., 0.25-0.30 inch thickness, or more or less). A waterproof membrane and tile are installed on the shower base at the installation site. The method of installation includes installing the premanufactured combination slab at an installation site, and applying a waterproof membrane and thinset-bonded tile with gap-filling grout. This provides a high quality, flexible design that is both efficient and cost-competitive after installation. The honeycomb is sufficiently thick to overcome compression and deformation issues prevalent during tile installation.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit under 35 U.S.C. § 119 (e) to U.S. Provisional Application Ser. No. 62/411,812, filed Oct. 24, 2016, entitled DAMAGE-RESISTANT SHOWER BASE AND INSTALLATION METHOD, the entire contents of which are incorporated herein.

BACKGROUND

The present invention relates to leak-proof water-draining shower bases and methods of installation, and more particularly relates to a shower base product including a foam slab with a sloped upper surface that is covered with damage-resisting slab (preferably honeycomb slab), and, at the installation site, also covered with a water-proof membrane and grouted tile. The present invention also includes a related method of installation and of manufacturing. It is contemplated that the present innovation is not limited to only shower bases, but instead can be used on many different collect-and-drain floors such as commercial kitchens and other wet areas.
It is known to install premanufactured shower bases in showers, such as in hotels, institutions, other commercial and domestic buildings, homes and condos, in order to provide a faster but high quality and lower cost installation. For example, Kik U.S. Pat. No. 8,230,535 discloses a shower base where the continuous and uninterrupted slope/contour of the upper surface (including the waterproof membrane) is critical to a good installation and avoidance of water leaks and water pooling issues. Kik '535 states that its product is believed to provide an efficient and quick installation, while minimizing skilled labor time. However, improvement is desired in the design of a shower base to allow for more flexibility and adjustability” to satisfy the wide number of variables that occur during installation. Specifically, while the shower base of Kik '535 has many advantages, further improvement is desired in terms of flexibility to adapt to an architect's design (in order to adapt to different floor configurations and floor shapes, and to different drain styles), flexibility of installation (such as the ability to connect to a drain based on its exact location at the installation site, which is never exactly at the specified location on drawings due to a number of construction and installation issues), and quality and efficiency and minimized cost of a high quality installation. The location of a floor drain opening in retrofit installations can be particularly problematic since locations relative to adjacent walls vary widely. Also, great care must be taken to avoid damage to the premanufactured assembly during installation.
One problem in particular is from compression and deformation issues to the upper surface of the base during installation. The “compression and deformation issues” are caused in large part by depressions and irregularities in the shower floor, resulting in water pooling and poor water flow to the drain, which in turn results in customer complaints and building owner complaints about poor draining. The compression and deformation issues to the base's upper surface can be caused by a variety of different mechanisms, including simple things like a plumber/installer placing a shoe or knee on the top surface during the installation (with the shoe or knee having sufficient weight or sharpness to cause a permanent depression that is reflected when tile is placed/installed at a later time on the upper surface), or by more difficult-to-manage items (such as damage or deformation during shipping, deformation during transport from the shipping container to the actual job site, or deformation occurring while the base is stored prior to installation, or damage or deformation while trying to fit a pre-manufactured base into a particular enclosed space to form the shower).
A shower base and a method of installation is desired that is flexible in configuration, flexible and adaptable to different drains and different floor slope designs, and that allows an efficient and productive install, yet minimizes installation time and in particular minimizes the time needed from highly skilled installers.

SUMMARY OF THE PRESENT INVENTION

In one aspect of the present invention, a shower base apparatus for placement on a floor-defining structure with a drain opening comprises a foam slab with an upper surface and a floor-engaging lower surface; and a honeycomb slab bonded to the upper surface of the foam slab to form a combination slab, the honeycomb slab forming a deformation-resisting layer on the foam slab, one of the foam slab and the honeycomb slab having a continuously sloped surface so that when bonded together and installed, any falling water will flow toward the drain opening.
In another aspect of the present invention, a water-directing apparatus for placement on a floor-defining structure with a drain opening comprises a foam slab with sloped upper surface and defining a drain-adjacent location; and a honeycomb slab bonded to the foam slab and forming a deformation-resisting layer on the foam slab and taking on a slope of the sloped upper surface so that when installed, falling water will flow toward the drain-adjacent location.
In another aspect of the present invention, a water-directing apparatus for placement on a floor-defining structure with a drain opening comprises a support slab defining a planar geometric shape with linear edges and top and bottom surfaces, the top and bottom surfaces defining a maximum thickness dimension and a non-constant thickness dimension that combine to define a continuous slope extending toward a drain-adjacent location; and a honeycomb slab bonded to the support slab and forming a deformation-resisting layer on the support slab and taking on a slope of the sloped upper surface so that when installed, falling water will flow toward the drain-adjacent location.
In still another aspect of the present invention, a method of installing a shower base apparatus in a shower structure at an installation site comprises providing a slab assembly including a tapered or flat foam slab with sloped upper surface, and a honeycomb slab bonded to the sloped upper surface of the polystyrene slab to form a deformation-resisting layer on the foam slab; installing the slab assembly and a drain apparatus relative to a drain hole in the shower structure; bonding a waterproofing membrane to the slab assembly; and installing tile on the waterproofing membrane.
The present innovation includes a tapered or flat slab (e.g., expanded or extruded polymer) with sloped upper surface (sometimes referred to herein as “PS wedge”) with a thin deformation-resisting slab (preferably a honeycomb slab that is less than about 0.500″, or more preferably about 0.250″-0.300″) bonded to the sloped upper surface of the foam slab wedge (e.g., PS wedge). It is contemplated that these pieces can be manufactured in many configurations and installed to create single slope or multi-slope floorings for use with trench or round drain bases. It is contemplated that the bases can be fastened to or supported by the sub-floor in a number of ways, using methods and materials known in the art.
Contrary to the shower base shown in Kik U.S. Pat. No. 8,230,535, the present innovation does not bond a waterproofing sheet to the honeycomb. Instead, in a preferred version of the present innovation, the waterproofing is bonded to the shower base after the shower base is secured to the sub-floor. Advantageously, the sheet of less than about 0.500″, or more preferably about 0.250″-0.300″ (+/−0.150) honeycomb is adequate to stop compression and deformation issues during tile installation, depending on on-site functional requirements. These “compression and deformation issues” cause depressions and irregularities in the shower floor, resulting in water pooling and poor water flow to the drain, which in turn results in customer and building owner complaints. The compression and deformation issues can be caused by a variety of different mechanisms, including simple things like a plumber/installer placing a shoe or knee or tool on the top surface with a force sufficient to cause deformation (i.e., with the shoe or knee or tool having sufficient weight or sharpness to cause a permanent depression that is reflected when tile is placed/installed on the upper surface), or by more difficult-to-manage items (such as damage or deformation during shipping, deformation during transport from the shipping container to the actual job site, or deformation occurring while the base is stored prior to installation), or installation related issues (e.g., trying to force-fit the product into an enclosed space when constructing a shower).
In one aspect of the present invention, a shower base apparatus includes at least one tapered or flat foam slab with sloped upper surface; and a honeycomb slab bonded to the sloped upper surface of the foam slab to form a deformation-resisting layer on the foam slab.
In a narrower aspect, the honeycomb slab has a thickness of less than 0.500″, or more preferably less than about 0.300″.
In a narrower aspect, there are at least two foam slabs, with their associated sloped upper surfaces sloping in different directions.
In a narrower aspect, there are at least two foam slabs, with their associated sloped upper surfaces combining to define a continuous slope direction.
An object of the present invention is to utilize the anti-deformation properties of honeycomb along with its other advantageous properties, while minimizing the high cost of an assembly that incorporates honeycomb.
These and other aspects, objects, and features of the present invention will be understood and appreciated by those skilled in the art upon studying the following specification, claims, and appended drawings.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a partially-installed shower base apparatus in a shower structure of a building.

FIG. 2 is a cross section through the drain and shower base apparatus of FIG. 1, the apparatus including a premanufactured combination of a foam slab (e.g. polystyrene foam) with sloped upper surface and thin honeycomb slab bonded on the sloped upper surface (referred to herein as “combination slabs”), a waterproof membrane, and tile bonded with thinset and tile joints filled with the appropriate grout.

FIG. 3 is an enlarged perspective view of the premanufactured combination of slabs forming the shower base in FIG. 2.

FIG. 4 is a perspective showing a first two of the premanufactured combination slabs with upper surfaces coplanar to form a constant slope and leading to a trench drain with a drain hole formed therein. FIG. 4 also shows two additional premanufactured combination slabs aligned with a right side of the first two combination slabs. FIG. 4 also shows an additional narrow strip of the combination slabs aligned with a right end of the trench drain.

FIG. 5 is similar to FIG. 4, but shows the trench drain in a middle region with narrow strips aligned with each end of the trench and also with large panels of pre-manufactured combination slabs on each side of the trench drain.

FIG. 5A is similar to FIG. 5 but shows one of the narrow strips exploded away to better show its relationship to the trench drain.

FIG. 6 is similar to FIG. 5 but shows the trench drain reversed so that its drain hole is nearer an opposite end of the trench drain.

FIG. 7 is a perspective view of the shower base apparatus including a trench drain and foam slab and honeycomb slab.

FIGS. 7A-7C are similar to the foam slab in FIG. 7, but with different thicknesses and shapes.

FIGS. 8-8A are views of the honeycomb slab cut to different dimensions, FIG. 8 being an enlarged small section and FIG. 8A being reduced in size to show the entire part.

FIG. 9 is a cross section showing the combination slab of FIG. 2, with the tile bonded with thinset to the waterproof membrane, with gaps filled with grout, as assembled onto a combination slab (honeycomb and foam slabs) as a fully-installed assembly.

FIG. 10 is a perspective view of an additional combination slab similar to the previously disclosed slabs, but having a non-planar upper surface that drains water toward a single corner.

FIGS. 10A-10B are respective side views of drain-adjacent edges of FIG. 10, and FIG. 10C is a cross section diagonally through the slab and taken through the common corner between the adjacent edges.

FIGS. 11-13 are perspective views of different installations incorporating the combination slab of FIG. 10.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1 is a perspective view of a partially-installed shower base apparatus in a shower structure 10 of a building. The shower structure 10 includes a floor surface, a first building wall (illustrated with drywall covering attached), and a second wall 13 (defined by the illustrated studs). The shower base apparatus is shown as partially installed in the shower structure 10. The shower base apparatus in FIG. 2 includes a combination slab 21, the combination slab 21 including at least one tapered or flat foam slab 22 (preferably polystyrene foam) with a sloped upper surface; and a deformation-resisting thin slab 23 (preferably a honeycomb slab of about 0.250-0.300 inch thickness) bonded to the sloped upper surface 22A of the foam slab 22 to form a deformation-resisting layer on the foam slab 22. The shower base apparatus 20 also includes a drain 24 (illustrated as a trench drain 24) with drain opening 24 a, a waterproofing membrane 25, and tile 26 bonded using thinset to the waterproofing membrane 25, with gaps between tiles filled with grout 27. It is noted that the thinset material isn't specifically shown in the figures, but skilled artisans will know that its thickness may vary depending on the material and installation requirements. The illustrated components 21, 25, 26 form a multi-slope surface (e.g., the illustrated orthogonal slopes A-D) for draining water toward the trench drain 24, which directs the water into its drain opening 24 a. It is contemplated that the components can be used to form a single slope surface (e.g., toward one side of a trench drain) or two-direction opposing slopes (e.g., toward opposite sides of a trench drain), or three-direction or four-direction slopes (toward multiple sides of a trench drain or of most commercially-available drains including non-trench drains). It is contemplated that the slopes can be formed in large part by tapered foam slabs or by thinset-supported flat foam slabs, each having a damage-resisting honeycomb slab on its upper sloped surface.
FIG. 2 is a cross section through the drain and shower base apparatus of FIG. 1, the apparatus including a premanufactured combination of a polystyrene foam slab with sloped upper surface and thin honeycomb slab bonded on the sloped upper surface, a waterproof membrane, tile (bonded using thinset), and tile gaps filled using grout.
FIG. 3 is an enlarged perspective view of the premanufactured combination of slabs forming the shower base in FIG. 2.
FIG. 4 is a perspective showing a first two of the premanufactured combination slabs 21 with upper surfaces coplanar to form a constant slope and leading to a trench drain with a drain hole formed therein. FIG. 4 also shows two additional premanufactured combination slabs 21 aligned with a right (far) side of the first two combination slabs 21. FIG. 4 also shows an additional narrow strip of the combination slabs 21 aligned with a right end of the trench drain. As illustrated in FIG. 4, the four adjacent large/square shower bases formed by the combination slabs 21 utilize tapered foam slabs (i.e. the taper in the foam forms the sloped upper surface when the foam is supported on thinset support material) with honeycomb slabs adhered to their sloped upper surface, causing water to drain in direction A. Contrastingly, the small combination slab 21 aligned with the right end of the trench drain 24 in FIG. 4 utilizes a flat foam slab with honeycomb slab adhered to its upper surface. The material supporting the small combination slab 21 is graded to a slight angle leading toward the trench drain 24, which causes the upper surface of the small (flat) combination slab 21 to drain water in direction C toward the trench drain 24.
FIG. 5 is similar to FIG. 4, but shows the trench drain in a middle region with the large combination slabs on a far side of the trench drain, but with narrow combination slabs (“strips ”) aligned with each end of the trench drain 24 and also with an additional combination slab 21 on the near side of the trench drain 24. In FIG. 5, the large combination slabs 21 (far side of the trench drain 24) include tapered foam slabs with a (flat) honeycomb slab bonded to its upper surface, the tapered foam slabs being the significant feature causing the upper surface to slope in direction “A.” The additional smaller combination slabs (i.e., the combination slabs at right and left ends of the trench drain 24 and on the near/close long edge of the trench drain 24) include flat foam slabs with honeycomb slabs bonded to their upper surface, with thinset material “canted” under the small combination slabs. The “canted” thinset causes the foam slab to be at a slight angle, thus being the significant feature that causes the additional combination slabs to have an upper surface that slopes in water-flow directions “B,” “C,” and “D” respectively.
FIG. 5A is similar to FIG. 5 but shows one of the narrow strips exploded away to better show its relationship to the trench drain 24.
FIG. 6 is similar to FIG. 5 but shows the trench drain reversed so that its drain hole is nearer an opposite end of the trench drain 24.
FIG. 7 is a perspective view of the shower base apparatus including a trench drain 24 and foam slab and honeycomb slab.
FIGS. 7A-7C are additional foam slabs similar to the foam slab in FIG. 7, but with different thicknesses and shapes. The additional foam slabs are covered with the damage-resisting honeycomb slab similar to the foam slab in FIG. 7, but it is noted that they could be designed for stacked layers of foam slabs.
FIGS. 8-8A are views of the honeycomb slab, FIG. 8 being enlarged to show details of the top and bottom scrim covering the honeycomb structure, and FIG. 8A being reduced to show an example of an overall part (before assembly to a foam slab). Notably, FIG. 8 illustrates the thickness as being 0.300 inches, but it is to be understood that a thickness could be 0.250 inches or more or less, depending on functional requirements of a particular installation. For example, a commercial kitchen installation may need to withstand relatively heavy carts and equipment, thus requiring a thicker honeycomb in order to accomplish the intended purpose of deformation resistance.
FIG. 9 is a perspective photograph showing a prototype combination slab of FIG. 2, and FIG. 8 illustrates a honeycomb slab which includes top and bottom layers of 50-150 GSM spun bonded non-woven material (e.g., “scrim”) to promote good adherence to the honeycomb core layer, and also shows the tile, grout, and combination slab (honeycomb and foam slabs) as a fully-installed assembly.
The present shower base apparatus focuses on a tapered or flat foam wedge (e.g. expanded or extruded polymer material such as polystyrene) with a thin (0.250″-0.300″, more or less) honeycomb slab bonded to the PS wedge. It is contemplated that the foam wedge can be 0.10 to 3.0 inches thick or more, and can be manufactured to have a uniform-direction-sloped upper surface or multi-direction-sloped upper surface. It is contemplated that the honeycomb slab can be made to conform to the sloped upper surface during manufacture. These pieces can be manufactured in many configurations to create single slopes or multiple slopes, for trench drains or for single-hole drain bases. The bases can be fastened to the sub-floor in a number of ways. Whereas the shower base shown in Kik '535 has the waterproofing bonded to the honeycomb, this novel (new) shower base does not have the waterproofing as an integral part of the shower base during premanufacture. Instead, it is preferably bonded to the shower base after it is secured to the sub-floor at the installation site. The sheet of 0.250″-0.300″ honeycomb has been tested to be adequate to stop compression issues prior to tile installation, depending on functional requirements of the installation. This novel method of installation is believed to be innovative and unobvious to known installation techniques in prior art. In particular, it is surprising and unexpected to reduce premanufacture and instead add a step to installation as part of providing a high quality and lower cost installation. Yet the present innovative method does that by reducing on-site damage and deformation issues related to often-encountered situations and events.
FIG. 10 is a perspective view of an additional combination slab 100 similar in sandwich construction (i.e., similar layers and thicknesses) to the previously disclosed combination slabs 21. Specifically, combinations slab 100 includes a supporting foam slab 101 and top honeycomb slab 102 bonded to the and supported on the foam slab 101, However, combination slab 100 has a non-planar upper surface 103 with multiple slopes F1-F5 extending toward a single lowest-thickness drain-adjacent corner 104, so that when installed on a horizontal support surface (i.e., a leveled shower floor structure), the water drains toward the single drain-adjacent corner 104.
The illustrated combination slab 100 (FIGS. 10A-10B) has corner- adjacent edges 105 and 106 that define the single drain-adjacent corner 104, and additional corner- remote edges 107 and 108 that complete its orthogonal shape. The upper surface 103 is non-planar and contoured so that water on it will flow by gravity toward the single drain-adjacent corner. Specifically, the illustrated corner- remote edges 107 and 108 define a constant thickness. The corner- adjacent edges 105 and 106 have a drain-remote end with a thickness that is equal to the corner- remote edges 107 and 108. However, corner- adjacent edges 105 and 106 then taper to a narrower thickness at the single drain adjacent corner 104. This establishes slopes F1 and F5 along the corner adjacent edges 105 and 106. Also, the slope F3 extends diagonally between the drain-remote corner 109 and drain-adjacent corner 104. As skilled artisans will understand, the slope F3 is slightly less than the slopes F1 and F5 since it extends over a greater distance with a same fall. Also, slopes F2 and F4 have a slope greater than slope F3 but less than slopes F1 and F5 due to a length over which they extend.
It is contemplated that the upper surface 103 can be different configurations. In a preferred form, the contour is formed in (e.g., cut into) the upper surface of the foam slab, and then the thin honeycomb slab is bonded to the foam slab, which causes the honeycomb slab to take on the shape and contour of the foam's upper surface. For example, the foam slab's upper surface can be cut so it defines linear lines from any point on the corner- remote edges 107, 108 to the drain-adjacent corner 104. The slopes F1-F5 can be any degree of slope desired, but the illustrated slopes F1-F5 are in the range typical for bathroom shower floor drain systems, which ranges are well known in the art.
FIGS. 11-13 are perspective views of different installations incorporating the combination slabs 21 and 100. FIG. 11 illustrates an installation with four slabs 100 arranged to flow water to the drain opening 121. The illustrated four combination slabs 100 are all a same size and all are rectangular, but it is contemplated that a size and shape of the slabs 100 can be varied to accommodate virtually any location of the drain opening 121. For example, FIG. 12 illustrates another installation with four combination slabs 100A leading to a drain hole 121A. Combination slabs 100A are the same construction as combination slab 100, but slabs 100A are triangular in shape such that they only have three corners, one edge being a constant thickness dimension and relatively longer than the other two drain-adjacent edges. All of the upper surface of the combination slab 100A slopes toward the drain opening 121A.
FIG. 13 is a perspective view similar to FIGS. 1 and 5, but incorporating four combination slabs 100 at corners of the pattern of four combination slabs 21, with all slopes extending toward the trench drain 121B. It is noted that abutting edges of all slabs 21 and 100A have a same (or similar) thickness so that tile can be overlaid across the joint without a step in height that would disrupt levelness of the tile.
It is to be understood that variations and modifications can be made on the aforementioned structure without departing from the concepts of the present invention, and further it is to be understood that such concepts are intended to be covered by the following claims unless these claims by their language expressly state otherwise.

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A shower base apparatus for placement on a floor-defining structure with a drain opening, comprising:

a foam slab with an upper surface and a floor-engaging lower surface; and

a honeycomb slab bonded to the upper surface of the foam slab to form a combination slab, the honeycomb slab forming a deformation-resisting layer on the foam slab, one of the foam slab and the honeycomb slab having a continuously sloped surface so that when bonded together and installed, any falling water will flow toward the drain opening.

2. The shower base apparatus of claim 1, wherein the foam slab's upper surface is the continuously sloped surface.

3. The shower base apparatus of claim 2, wherein the honeycomb slab has a continuous constant thickness and conforms when bonded to the upper surface of the foam slab to thus take on a shape of the upper surface of the foam slab.

4. The shower base apparatus of claim 1, wherein the honeycomb slab is less than 0.500 inches.

5. The shower base apparatus of claim 4, wherein the honeycomb slab is less than 0.300 inches.

6. The shower base apparatus of claim 5, wherein the honeycomb slab is within +/−0.050 of a range of 0.10 inches to 0.30 inches.

7. The shower base apparatus of claim 1, wherein the foam slab includes polystyrene material.

8. The shower base apparatus of claim 1, wherein the foam slab is tapered and includes a sloped upper surface when supported horizontally.

9. The shower base apparatus of claim 8, including a waterproof membrane on the honeycomb slab.

10. The shower base apparatus of claim 9, including tile on the waterproof membrane.

11. The shower base apparatus of claim 1, including a second combination slab identical in laminar construction to the first combination slab, but the first and second combination slabs being positioned with associated sloped upper surfaces sloping in different directions.

12. The shower base apparatus of claim 1, including a second combination slab identical in laminar construction to the first combination slab, but the first and second combination slabs being positioned with associated sloped upper surfaces sloping in a same direction and defining a continuous combined slope.

13. A water-directing apparatus for placement on a floor-defining structure with a drain opening, comprising:

a foam slab with sloped upper surface and defining a drain-adjacent location; and

a honeycomb slab bonded to the foam slab and forming a deformation-resisting layer on the foam slab and taking on a slope of the sloped upper surface so that when installed, falling water will flow toward the drain-adjacent location.

14. The apparatus of claim 13, wherein the sloped upper surface of the foam slab is shaped to cause falling water to flow toward a drain point.

15. The apparatus of claim 14, wherein a combined thickness of the foam slab and the honeycomb slab defines two drain-adjacent edges and at least one drain-remote edge, the at least one drain-point-remote edge having a constant dimension and a maximum thickness of the apparatus, and all portions of the sloped upper surface including the two drain-adjacent edges sloping toward the single drain point.

16. The apparatus of claim 15, wherein the at least one drain-point-remote edge includes two drain-remote edges.

17. A water-directing apparatus for placement on a floor-defining structure with a drain opening, comprising:

a support slab defining a planar geometric shape with linear edges and top and bottom surfaces, the top and bottom surfaces defining a maximum thickness dimension and a non-constant thickness dimension that combine to define a continuous slope extending toward a drain-adjacent location; and

a honeycomb slab bonded to the support slab and forming a deformation-resisting layer on the support slab and taking on a slope of the sloped upper surface so that when installed, falling water will flow toward the drain-adjacent location.

18. A method of installing a shower base apparatus in a shower structure at an installation site, comprising:

providing a slab assembly including a tapered or flat foam slab with sloped upper surface, and a honeycomb slab bonded to the sloped upper surface of the foam slab to form a deformation-resisting layer on the foam slab;

installing the slab assembly and a drain apparatus relative to a drain hole in the installation site;

bonding a waterproofing membrane to the slab assembly; and

installing tile on the waterproofing membrane.

19. The method of claim 18, wherein the honeycomb slab is 0.10 to 0.30 inches thick.

20. The method of claim 19, wherein the foam slab is 0.10 to 3.00 inches thick.