Waterproof base with composite shower curb, and methods of fabrication and installation thereof

A method of fabricating a shower base system, said method comprising:

• forming an expanded polymer core to define a top surface and a bottom surface, the top surface sloping toward a drain opening extending through the polymer core from the top surface to the bottom surface, and further comprising a drain receiving recess in the top surface and extending at least partially through the expanded polymer core surrounding the drain opening;
• applying a waterproof top layer over the top surface of the expanded polymer core;
• applying a bottom skin to the bottom surface of the expanded polymer core at least around the drain opening;
• and
• installing a composite curb along at least one side of the expanded polymer core.

A method of installing a waterproof shower base, said method comprising:

• providing an assembly comprising an expanded polymer core defining a top surface and a bottom surface, the top surface sloping toward a drain opening extending through the polymer core from the top surface to the bottom surface, and further comprising a drain receiving recess in the top surface and extending at least partially through the expanded polymer core surrounding the drain opening, said drain receiving recess defining an annular surface directed toward the top surface to define an upper drain clamping surface, the assembly further comprising a waterproof top layer applied over the top surface of the expanded polymer core, and a bottom skin applied to the bottom surface of the expanded polymer core at least around the drain opening;
• placement of the assembly onto a substrate, with the drain opening aligned with a lower drain element in the substrate;
• attaching an upper drain element against the drain clamping surface of the drain receiving recess of the assembly and in engagement with the lower drain element;
• and
• installing a composite shower curb base along at least one side of the expanded polymer core.

A method of installing a drainage floor, said method comprising:

• preparing a subfloor surface;
• applying a closed-cell foam core over the prepared subfloor surface;
• and
• applying a compressible soft material layer over the closed-cell foam core.