The bathtubs themselves are identical in design, the only difference being their method of installation. Undermount bathtubs are installed beneath a rim so that the bathtub’s weight is distributed between the floor structure and the rim. Drop-in bathtubs are installed above the rim, placing much of their weight on the rim itself.

Both drop-in and undermount tubs can be suitable for various bathroom sizes. However, undermount tubs are often preferred for smaller bathrooms where space optimization is crucial, while drop-in tubs can work well in larger bathrooms with ample space for the surrounding platform or deck.

Drop-in bathtubs. Drop-in tubs are sunk into a prepared deck, or wall surround, that supports them. A drop-in tub can also be an alcove tub depending on the wall surrounds. Undermount bathtubs. An undermount bathtub is installed beneath a rim and has a deck or other surround; it sits on feet or directly on the floor

In conclusion, the choice between an undermount tub and a drop-in tub depends on your preferences, bathroom design, and available space. Choose an undermount tub if you prefer a sleek, modern look, and have a smaller bathroom or limited floor space. Undermount tubs are easy to clean and create a visually open bathroom environment.

It’s like a drop-in tub except with a flat rim. Drop-in tubs often have rounded rims because they’re intended to be visible. You can use an undermount as a drop-in tub, but you can’t always use a drop-in as an undermount. Undermount tubs feature feet or a flat basin that rests on the floor. They’re installed with a surround and deck.