How to Install a Cast Iron Tub: Step-by-Step Guide

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Installing a cast iron tub is a great way to add a touch of elegance to any bathroom. However, it can be daunting for those who have never done it. Fortunately, anyone can easily install a cast iron tub with the right tools and preparation.

Before beginning the installation process, it is important to understand the basics of cast iron tubs. Cast iron is a durable, long-lasting material that can withstand high temperatures and heavy use. However, it is also very heavy and requires careful handling during installation. Additionally, cast iron tubs are prone to chipping and scratching, so it is important to take precautions to prevent damage during installation and use.

To install a cast iron tub, you will need various tools and materials, including a level, a drill, a wrench, and plumbing supplies. You will also need to prepare the area where the tub will be installed, including ensuring the floor is level and the plumbing is in good condition. Once you have completed these steps, you can begin the installation process, which involves attaching the tub to the plumbing and securing it. Finally, you can add finishing touches, such as caulking and sealing the tub to ensure it is watertight and looks great.

Key Takeaways

  • Installing a cast iron tub requires careful handling and preparation to prevent damage and ensure a successful installation.
  • The installation involves attaching the tub to the plumbing, securing it in place, and adding finishing touches such as caulking and sealing.
  • Regular maintenance, such as cleaning and resealing, can help prolong the life of a cast iron tub and prevent damage.

What are Cast Iron Tubs?

Signature Hardware 260281 Henley 66" Cast Iron Double-Ended Pedestal Tub with 7" Rim Holes

Cast iron tubs have been a popular choice for homeowners for many years. They are known for their durability, sturdiness, and classic look. Cast iron is a type of metal made by melting iron and adding other materials like carbon and silicon. The resulting material is strong, durable, and resistant to chipping and cracking.

One of the primary benefits of a cast iron tub is its weight. Cast iron is a dense material, so these tubs can weigh several hundred pounds. This weight can be advantageous because it makes the tub sturdy and stable. However, it can also be a challenge during installation.

Cast iron tubs are available in various shapes and sizes, making them versatile for any bathroom. They can be found in traditional clawfoot styles or modern, sleek designs. The enamel coating on the tub’s surface is another feature that makes it popular. The enamel provides a smooth and easy-to-clean surface resistant to scratches and stains.

When it comes to installation, cast iron tubs require careful handling. Due to their weight, they can be difficult to move and maneuver into place. It is recommended to have professional installers handle the installation process to ensure that the tub is securely installed. Additionally, it is important to ensure that the floor can support the tub’s weight and that the plumbing is installed correctly.

Overall, cast iron tubs are a classic and durable choice for any bathroom. They offer a range of benefits, including sturdiness, durability, and a classic look. However, they also require careful handling and installation to ensure they are installed correctly.

Also Read: Cast Iron VS Acrylic Tub

How To Install A Cast Iron Tub 

Tools and Materials Needed

Before starting the installation process, ensuring all the necessary tools and materials are available is important. Here are the tools and materials required to install a cast iron tub:


  • Adjustable wrench
  • Caulking gun
  • Drill
  • Hammer
  • Level
  • Measuring tape
  • Pipe wrench
  • Pliers
  • Safety glasses
  • Screwdriver
  • Silicone caulk
  • Tubing cutter


  • Cast iron tub
  • Drain kit
  • Overflow kit
  • Pipe joint compound
  • Plumbing fittings
  • PVC cement
  • Shims
  • Water supply lines

It is important to note that some additional tools and materials may be required depending on the specific installation requirements and the condition of the bathroom. It is recommended to review the installation instructions the manufacturer provides before beginning the installation process.

The installation process can begin once all the necessary tools and materials are available.

Preparation Steps

A few preparation steps must be taken before installing a new cast iron tub. This section will cover the two primary preparation steps: removing the old tub and preparing the bathroom space.

Removing Old Tub

The first step in preparing for a new cast iron tub installation is removing the old one. This can be challenging, especially if the old tub is cast iron. Here are a few steps to follow when removing an old tub:

  1. Turn off the water supply and disconnect all plumbing fixtures.
  2. Remove any caulking or adhesive around the tub.
  3. Cut the tub into smaller pieces with a reciprocating saw or sledgehammer.
  4. Remove the pieces of the tub from the bathroom.

Preparing the Bathroom Space

Once the old tub is removed, it’s time to prepare the bathroom space for the new cast iron tub. Here are a few steps to follow:

  1. Clean the area where the old tub was located.
  2. Check the bathroom floor for any damage and repair as necessary.
  3. Measure the space where the new tub will be installed to ensure it will fit properly.
  4. Install any necessary plumbing fixtures, such as a new drain or water supply lines.
  5. Ensure the floor is level and add any necessary support for the new tub.

Following these preparation steps will make installing a new cast iron tub much smoother and easier. It’s important to take the time to properly remove the old tub and prepare the bathroom space to ensure a successful installation.

Installation Process

Installing a cast iron tub can be challenging, but it can be done successfully with proper preparation and attention to detail. The installation process can be broken down into three main steps: positioning the tub, securing the tub, and connecting plumbing fixtures.

Positioning the Tub

Before installing the tub, ensure the floor is level and can support the tub’s weight. Use a level to check the floor and adjust as necessary. Then, position the tub in the desired location and mark the outline of the tub on the floor.

Next, apply a layer of mortar or adhesive to the floor within the outline of the tub. Carefully lower the tub onto the mortar or adhesive, ensuring it is level. Check the level again and adjust before the mortar or adhesive sets.

Securing the Tub

Once the tub is in position, secure it to the wall studs using screws or bolts. Use a level to ensure the tub is still level and adjust as necessary.

To prevent water from leaking underneath the tub, apply a bead of silicone caulk around the base of the tub where it meets the floor. Be sure to use a caulk specifically designed for use in bathrooms and can withstand water exposure.

Connecting Plumbing Fixtures

The final step is to connect the plumbing fixtures to the tub. This includes the drain, overflow, and water supply lines. Follow the manufacturer’s instructions for the specific fixtures being installed.

To prevent leaks, apply the plumber’s tape to the threads of the fittings before connecting them. Tighten the fittings with a wrench, but be careful not to over-tighten and damage the fittings or the tub.

With the plumbing fixtures connected, turn on the water and check for leaks. If there are no leaks, the installation is complete.

Installing a cast iron tub requires careful preparation and attention to detail, but it can be done successfully with the right tools and knowledge.

Finishing Touches

After successfully installing the cast iron tub, some finishing touches need to be done to ensure proper functioning and longevity of the tub. This section will discuss two important steps: Sealing the Tub and Testing the Installation.

Sealing the Tub

Sealing the tub is important to prevent water from seeping through the gaps between the tub and the walls or floor. Before sealing, make sure the tub is clean and dry. Use a silicone-based caulk to seal the tub. Apply a continuous bead of caulk around the tub’s edges, where it meets the walls and floor. Smooth the caulk with a caulk smoothing tool or your finger to ensure it is evenly distributed and has no gaps.

Testing the Installation

After sealing the tub, testing the installation to ensure no leaks is important. Fill the tub with water and let it sit for at least 24 hours. Check the area around the tub for any signs of water leakage. Drain the tub and reseal the affected area with caulk if leaks occur. Let the caulk dry completely before testing again.

If there are no leaks, test the drain and overflow by filling the tub with the overflow and draining it. Check the area around the drain and overflow for any signs of water leakage. If there are any leaks, tighten the connections or replace the gasket. The tub is ready for use once the drain and overflow are working properly.

In conclusion, sealing the tub and testing the installation are crucial to ensure the cast iron tub is properly installed and functioning. By taking the time to properly seal the tub and test the installation, homeowners can avoid costly water damage and enjoy their new tub for years to come.

Maintenance Tips for Cast Iron Tubs

Cast iron tubs are known for their durability and long-lasting nature. However, proper maintenance is crucial to ensure they stay in good condition for years. Here are some tips for maintaining your cast iron tub:

  • Cleaning: Regular cleaning is essential to keep your cast iron tub looking new. Avoid using abrasive cleaners or scrubbers that can scratch or damage the surface. Instead, use a mild cleaning solution and a soft cloth or sponge to wipe down the tub. Rinse thoroughly with warm water and dry with a soft towel.
  • Avoid Harsh Chemicals: Harsh chemicals such as bleach, ammonia, and drain cleaners can damage the finish of your cast iron tub. Avoid using these products and opt for mild, non-abrasive cleaners instead.
  • Prevent Stains: To prevent stains, avoid leaving soap, shampoo, or other bath products sitting in the tub for extended periods. Rinse the tub thoroughly after each use to remove any residue. If stains occur, gently scrub the affected area using baking soda and water paste.
  • Repair Chips and Scratches: Over time, your cast iron tub may develop chips or scratches. While these can be unsightly, they can lead to rust and other damage if left untreated. Use a cast iron repair kit found at most hardware stores to repair chips and scratches. Follow the manufacturer’s instructions carefully for best results.
  • Keep the Tub Level: A cast iron tub that is not level can cause water to pool in certain areas, leading to damage and potential leaks. Regularly check the level of your tub and make any necessary adjustments to ensure that it is sitting evenly.

Following these simple maintenance tips, you can keep your cast iron tub looking and functioning like new for years.

Frequently Asked Questions

How do I secure a cast iron tub in place?

To secure a cast iron tub in place, it is recommended to use a mortar bed. First, level the floor where the tub will be placed. Then, create a mortar bed by mixing sand, cement, and water. Spread the mortar bed evenly on the leveled floor and place the tub on top. Make sure the tub is level in all directions and adjust as necessary. Allow the mortar to dry completely before continuing with the installation.

What is the best way to get a cast iron tub upstairs?

Getting a cast iron tub upstairs can be challenging due to its weight. It is recommended to hire professional movers who have experience moving heavy objects. They will have the necessary equipment, such as a dolly and straps, to safely move the tub upstairs. It is important to ensure that the stairs are wide enough to accommodate the tub and that there are no obstacles.

What are the steps to install an alcove bathtub?

First, remove the old tub and any debris to install an alcove bathtub. Then, install the drain and overflow assembly according to the manufacturer’s instructions. Next, install the plumbing fixtures, such as the faucet and showerhead. Finally, install and secure the new tub using a mortar bed or adjustable feet.

How do I install a bathtub without access underneath?

If there is no access underneath the bathtub, using a freestanding tub or a tub with adjustable feet is recommended. These types of tubs can be leveled and secured without needing access underneath. If a built-in tub must be used, it may be necessary to create an access panel to reach the plumbing and secure the tub in place.

What is the process for leveling a cast iron tub?

First, to level a cast iron tub, ensure the floor is level. Then, place the tub in position and use a level to check that it is level in all directions. Adjust the feet or use shims as necessary to achieve a level installation. It is important to ensure that the tub is level to prevent water from pooling in one area and causing damage.

What are the steps to install a garden tub?

First, remove the old tub and any debris to install a garden tub. Then, install the drain and overflow assembly according to the manufacturer’s instructions. Next, install the plumbing fixtures, such as the faucet and showerhead. Finally, install and secure the new tub using a mortar bed or adjustable feet. It is important to ensure that the tub is level and enough space around it for easy access and cleaning.