Support for shower pan or tub

1. A multi-layer support for supporting a shower pan having a contoured underside and a shower pan opening, the support comprising:

a tray comprising a substantially flat bottom panel and four side walls integrally connected to and extending upward from the bottom panel, the bottom panel defining a tray opening having a perimeter, the tray defining a cavity for holding an intermediate layer and a top layer;

an intermediate layer disposed within the cavity adjacent the bottom panel, the intermediate layer being substantially planar and defining an intermediate layer opening having a diameter, the intermediate layer comprising a substantially flat bottom surface, a substantially flat top surface and a perimeter; and

a top layer made of expanded polystyrene and disposed within the cavity adjacent the intermediate layer, the top layer comprising a substantially flat bottom surface, a concave top surface and a perimeter, the top layer defining a top layer opening having a diameter and positioned to communicate with the intermediate layer opening, the top surface sloping inwardly from the perimeter to the top layer opening; wherein

the tray opening, intermediate layer opening and top layer opening are vertically aligned and together form a drain hole.

2. The support of claim 1 wherein:

the bottom panel has a constant thickness and a density of between about 0.8 PCF and about 10 PCF;

the intermediate layer is more rigid and less deformable than the tray and the top layer, has a constant thickness, and has a density of between about 25 and about 75 PCF; and

the top layer has a variable thickness and a density of between about 0.8 and 10 PCF.

3. The support of claim 1 wherein:

the bottom panel has a constant thickness of about 0.43 inches;

the intermediate layer has a constant thickness of between about 0.06 inches and about 1.00 inches; and

the top layer has a thickness that varies from about 0.88 inches at its perimeter to about 0.25 inches near the top layer opening.

4. The support of claim 1 wherein:

the intermediate layer is glued to the top layer and to the tray.

5. The support of claim 4 wherein:

the top layer is glued to the shower pan.

6. The support of claim 1 wherein:

the tray further comprises a cylindrical wall extending upward from the perimeter of the tray opening, the cylindrical wall having an outer diameter;

the diameter of the intermediate layer opening is about the same as the outer diameter of the cylindrical wall; and

the diameter of the top layer opening is about the same as the outer diameter of the cylindrical wall.

7. The support of claim 1 wherein both the tray and the top layer are molded and have an exterior skin that increases their tear strength and tear resistance.

8. The support of claim 1 wherein the tray and the top layer are further made of regrind or recycled material.

9. The support of claim 1 in combination with a shower pan, the support being attached to an underside of the shower pan, wherein the intermediate layer and the top layer are completely encapsulated between the tray and the shower pan.

10. The support of claim 1 in combination with a shower pan, the support being attached to an underside of the shower pan, wherein the tray side walls abut the underside of the shower pan.

11. The support of claim 9 wherein the support and the shower pan encapsulate the intermediate layer and the top layer between the support and the shower pan with little or no empty space therebetween.

12. A method of making a support for supporting a shower pan, the method comprising the steps of:

(a) providing a tray made of expanded polypropylene, the tray comprising a substantially flat bottom panel and four side walls extending upward from the bottom panel, the bottom panel defining a tray opening, the tray defining a cavity for holding an intermediate layer and a top layer;

(b) positioning a substantially flat intermediate layer made of oriented strand board and defining an intermediate layer opening within the cavity so that the intermediate layer opening is vertically aligned with the tray opening and gluing the intermediate layer to the bottom panel;

(c) providing a top layer made of expanded polystyrene and comprising a substantially flat bottom surface, a perimeter and a concave top surface that slopes inwardly from the perimeter toward a top layer opening; and

(d) gluing the bottom surface of the top layer to the intermediate layer so that the top layer opening is vertically aligned with the intermediate layer opening and the tray opening.

13. The method of claim 12 comprising the additional step of:

(e) gluing the top layer to the shower pan.