Premium Undermount Drop-In Whirlpool Bath with Extra-Wide Flange

For interior designers and architects planning a custom built-in bathroom feature, standard freestanding tubs can limit creative freedom. A custom deck finished in natural teak wood, stone tile, or polished concrete requires a specialized drop-in massage bathtub that integrates seamlessly with the surrounding materials. Our premium undermount drop-in whirlpool bath features an engineered, extra-wide outer rim flange that distributes weight evenly across your custom decking support frame, ensuring a completely flush, clean, and professional finish.

Customizable Jet Arrays & Bottom Air-Injection Plenums

Because this tub is designed for high-end custom builds, the internal hydrotherapy setup is optimized for premium comfort. The extra-deep basin floor is lined with multiple low-profile brass air-injection nozzles that release a steady stream of thousands of warm micro-bubbles, creating a relaxing, weightless sensation throughout the body. The water intake grate is strategically positioned at the lowest point of the tub floor to ensure the system drains completely after every use, leaving no stagnant water behind. The spacious interior layout provides plenty of room for stretching out, making it an excellent choice for custom wellness layouts.

Built on a Rigid Heavy-Duty Stainless Steel Sub-Frame

At HSPA Industrial Limited, located in #3 Building, Shushan International Enterprises Park, we understand that drop-in tubs are difficult to reinstall if a structural failure occurs. That’s why we build this model over a heavy-duty, fully welded stainless steel sub-frame with multiple cross-braces and adjustable threaded legs. This rigid foundation guarantees that even when filled to maximum water capacity with an adult bather inside, the acrylic edge will not flex away from your custom stone or tile deck, preventing grout cracks and water leaks. View detailed framing blueprints and technical specs atwww.h-spas.com.