Abstract: In the method of forming a spa tub, the steps that include providing a tub side wall having an inner side and an outer side, the tub having an interior to receive liquid; and providing a recess inwardly of the outer side of the tub side wall and below the top level of the side wall, to receive at least one of the following elements: edge extent of a flexible outer jacket for the side wall, the jacket extending below said recess; edge extent of a shoulder jacket that extends over the top of the side wall; edge extent of a tub top cover.

Abstract: Tub apparatus comprising a foamed, resiliently compressible, plastic tub wall having an inner side and an outer side, the tub having an interior to receive liquid, and ports extending through the side wall; a plastic pack having a cavity formed therein; a pump unit received in the cavity and protectively enclosed by the plastic pack; and tubular duct structure connected with the pump unit and extending from the cavity to the ports for circulating liquid between the tub interior and the pump unit.

Abstract: Tub apparatus comprising a foamed, resiliently compressible, plastic tub wall having an inner side and an outer side, the tub having an interior to receive liquid, and ports extending through the side wall; a plastic pack having a cavity formed therein; a pump unit received in the cavity and protectively enclosed by the plastic pack; and tubular duct structure connected with the pump unit and extending from the cavity to the ports for circulating liquid between the tub interior and the pump unit.

Abstract: Tub apparatus includes a foamed resiliently compressible plastic tub wall having an inner side and an outer side, the tub having an interior to receive liquid; a tensile liner adjacent the wall side, the liner and characterized in that it resists outward expansion in response to loading exerted by liquid filled into the tub interior; and including ports extending through the side wall and liner for circulating liquid between the interior of the tub and the exterior thereof. The plastic wall is typically locally heat cored in situ and provided with elbow fittings having venturis for efficient water, and water and air flow.

Abstract: Tub apparatus includes a foamed resiliently compressible plastic tub wall having an inner side and an outer side, the tub having an interior to receive liquid; a tensile liner adjacent the wall side, the liner and characterized in that it resists outward expansion in response to loading exerted by liquid filled into the tub interior; and including ports extending through the side wall and liner for circulating liquid between the interior of the tub and the exterior thereof. The plastic wall is typically locally heat cored in situ and provided with elbow fittings having venturis for efficient water, and water and air flow.

Abstract: Tub apparatus includes a foamed resiliently compressible plastic tub wall having an inner side and an outer side, the tub having an interior to receive liquid; a tensile liner adjacent the wall side, the liner and characterized in that it resists outward expansion in response to loading exerted by liquid filled into the tub interior; and including ports extending through the side wall and liner for circulating liquid between the interior of the tub and the exterior thereof. The plastic wall is typically locally heat cored in situ and provided with elbow fittings having venturis for efficient water, and water and air flow.

Abstract: Tub apparatus including:(a) a foamed plastic tub wall having an inner side and an outer side, the tub having an interior to receive liquid,(b) a tensile liner adjacent the wall side, the liner comprising interwoven strips of pre-stretched plastic material characterized in that the liner resists outward expansion in response to loading exerted by liquid filled into the tub interior.

Abstract: A water supply and heating package, for a hot tub, spa, or pool comprising(a) a support,(b) water circulating structure carried by said support and including a pump and connections circulating water from and toward the interior of the hot tub, spa or pool,(c) said structure including an electric motor connected in driving relation with said pump, and including a shunt duct connected with said water circulating structure and located to receive heat generated by operation of said motor to heat a side stream of said water passing through said shunt duct.Also, the apparatus may include a foamed plastic sheet or sheets wound in a spiral to form multiple layers, and defining an insulative, upstanding side wall of a tub, and a bottom wall attached to the side wall.