Sun Aug 06 2023

An Undermount Tub - An Ultimate Guide in 2023

An Undermount Tub - An Ultimate Guide

Are you looking for something different from a standard bathtub? Do you want your bathroom to stand out among your friends and family’s bathroom? An undermount tub can be the best solution for changing your bathroom environment to a different level. 

You might be wondering if all of the bathtubs satisfy the major need of providing the best spa-like experience in the comfort of your home, what makes undermount tubs different from other bathtubs?

According to AlliedMarketResearch, the drop-in tub is the third most popular type of bathtub on the market. But is the drop-in tub the same as the undermount tub? That is half right.

It sounds confusing, but do not worry, in the upcoming blocks, we will discuss the difference between the undermount and drop-in tub, and all the important things to know about the undermount tub so that you can make an informed decision on your purchase. 

An Undermount Tub – What Is It?

An undermount tub is a type of bathtub that is installed underneath a rim. Now, this is the place where the undermount tub and the drop-in genuinely differ. Usually, the drop-in bathtub is structured in a way that the bathtub is visible thanks to the flat rim.


Undermount tubs are installed directly on the floor with a surround and a deck (a crevice on the floor), thanks to the flat feet. This surround and deck help to cover the rim.

This creates a look where the surface of the deck smoothly coexists with the undermount tub making the tub “invisible” by blending with the bathroom floor.

So, the difference between a drop-in and an undermount tub is that the drop-in tub is visible and the undermount tub is not as much.

The undermount tub is slightly better in one aspect, which is weight distribution. Since the tub installation is directly placed on the floor structure and the flat rim, the weight is equally distributed and has a low possibility of creating floor damage.

Apart from the appearance and the installation method, the undermount and the drop-in bathtub are identical to each other.

The 3 Types of Styles in an Undermount Bathtub

The following three types of styles in undermount bathtubs are designed with an objective in mind, which is the bathtub is suited for both large and luxurious, as well as small bathrooms. 


  1. Oval-shaped undermount bathtubs
  2. Standard-shaped undermount bathtubs
  3. Corner undermount bathtub.

1. Oval-Shaped Undermount Bathtubs

Oval-shaped undermount bathtubs are more rounded than the standard-shaped undermount tub, meaning more surface area, while still being smaller than the normal undermount bathtub. This is definitely the better choice for a longer soaking session due to its great comfort. Due to round corners, these types of bathtubs are generally the choice for a jacuzzi or a hot tub. 

2. Standard Undermount Bathtubs

These types of bathtubs are placed on the floor structure and the flat rim for the support and the surrounding helps to blend the bathtub edges and makes it look camouflaged with the bathroom floor. This is the popular choice among the three styles on the market. 

3. Corner Undermount Bathtubs

This is a blend of both oval and standard-type undermount bathtubs. This results in a triangular shape. Oval on the one side and pointy on the other. One of the major benefits of a corner undermount bathtub is saving floor space. The shape helps you to get a comfortable and compact soak for a longer period of time. 

Types of Undermount Bathtub Material

Like other bathtub types, undermount bathtubs also come in varieties of materials ranging from lightweight to heavyweight material. This is one of the major deciding factors for the undermount bathtub’s price. Lightweight material, such as acrylic is considerably cheaper than copper or even cast iron. So, if you are looking for a cheaper undermount tub, it is recommended to choose lightweight material as the bathtub’s material.

But, what about the benefits? 


Each bathtub material has its own merits and demerits. We will take a look at popular bathtub material and its pros and cons.

Fiberglass – Considered the “featherweight” bathtub material, fiberglass can be the most inexpensive bathtub material on the market. It is also one of the easiest materials to work with. You can easily manipulate the material in order to get your desired shape and size. But, there is a notable disadvantage, which is durability. 


Fiberglass is the worst when it comes to durability and does not handle external force very well. Along with that, it is porous, meaning that it is much easier to get water damage, and it is not the best when it comes to heat retention. 


Acrylic – Next to fiberglass, acrylic is a lightweight bathtub material. You might think that, since it is light, the durability is the same as the fiberglass. But that is not the case.  Considering the weight of the material, durability is notably good, thanks to the fiberglass reinforcement in between the acrylic sheet. Also, the heat retention and resistance to minor structural abnormalities are better than the fiberglass which makes it a better choice for your inexpensive undermount bathtub.  It is also non-porous, meaning water does not enter the material surface and causes water damage. 


Cast iron – Definitely better than acrylic and fiberglass, cast iron is one of the best choices when it comes to undermount bathtubs. It has great durability and heat retention, and it is non-porous meaning less or no water damage occurs. 


One of the big disadvantages when it comes to cast iron is the weight. Cast iron can be on par with copper when it comes to weight. So, there is a good chance that you have to reinforce your bathroom floor to support the weight of the tub.


Average Cost of an Undermount Bathtub

Undermount bathtubs tend to be more expensive than normal freestanding or clawfoot bathtubs. The main reason is that the actual bathtub is directly installed on the floor surface (a crevice) and this step can cost you extra money on top of buying the bathtub. This process can cost anywhere between $100-$200, depending on the size and tile requirement.

The actual cost of an undermount tub can range from $500-$5000, depending on the size, type, and actual bathtub material.

So, if you are looking for a medium size undermount tub with lightweight material, like acrylic in your bathroom, you can expect the total cost, including the installation, to be from $700-$1000.


  • Can all drop-in tubs be undermount tubs?
  • The simple answer is, you can use the undermount tub as the drop-in bathtub, but you cannot use the drop-in bathtub as an undermount tub. The main reason is the installation process. The drop-in bathtub requires the rim to be placed on the top of the bathtub, unlike the undermount tubs.

  • Can an undermount tub have a shower?
  • Only when the undermount tub is installed near the wall. It is not common practice to install a shower with an undermount tub. The main purpose of an undermount tub is to soak for a longer period of time. But, it is possible to install a shower with your undermount bathtub setup.

  • Which is better: an undermount tub or a drop-in?
  • Apart from the installation process, a drop-in and an undermount are identical. From an installation perspective, a drop-in bathtub is better, since it is easy and quick to install. 

    Final Thoughts

    Bathtubs are great tools that help you to de-stress and rejuvenate your body and mind. Freestanding and clawfoot tubs are good tools, but the comfort offered by the undermount tub can be better. With simple extra steps in the installation, you can see the actual difference in your soaking session. If you are looking for an undermount tub, Magnus Home products offer good bathtubs, which you can see here.

    This article hopes to have provided enough information on undermount tubs, so you can decide whether the tub is for your household or not.