An undermount tub is set into a floor or deck, with the rim of the tub completely covered by the material from which the deck or floor is made. The entire weight of the tub is supported by the floor beneath it, as it does not hang from the edge of the deck like a drop-in tub would. The tub itself will generally be constructed of cast iron or acrylic, while the flooring around it may be made of stone or tile.
The choice of using an undermount tub in a person’s bathroom will most likely be determined by who lives in the home. For example, small children and older adults may find it difficult to enter and exit the bathtub because of its design. Many of the tubs do not have steps or seats inside of them, which can make it more difficult for some people to step into. If the tub is set at floor level, there is always a risk that a little child may accidentally fall into the tub as well.
These types of tubs can come in either cast iron or acrylic material. Both of these materials can be kept clean easily, but both are different when it comes to weight. The cast iron will be much heavier than the acrylic and will generally need more floor support when it is installed. Cleaning will have to be carefully done with a cast iron surface to prevent scratches on the protective enamel, which can lead to rust.
Stone is most often used as the deck material around an undermount tub. This type of material can be costly to install because the edges of the stones have to be shaped so they do not damage the tub. Undermount bathtubs are typically large, so more material will often be needed to surround the tub, which can add to the cost.
The materials that are used for the undermount tub and the deck will most likely play a heavy role when it comes to removing the tub for remodeling purposes. With this type of tub, the deck covers the rim and must be removed completely before the bathtub can come out. Materials such as stone can make this job more difficult and a lot more expensive. Once the deck is removed, the undermount tub can then be taken out. Acrylic tubs weigh less than cast iron and will be easier to remove.