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Weight is a crucial factor when buying a heavy bathtub. It affects delivery access, installation cost, structural safety, and even the long-term performance of your bathroom floor. One of the most common planning questions homeowners ask is how much a cast-iron tub weighs, and the answer depends on more than just size.
Cast iron tubs are renowned for their longevity and ability to retain heat; however, their solid construction makes them much heavier than modern tubs. A homeowner who ignores this point during a renovation may face issues with installation and long-term stability.
In this guide, we explain the weight differences among various cast-iron bathtub designs and sizes so that you can choose the right tub for your needs.
What are Cast Iron Tubs?
Cast iron tubs are made by pouring molten cast iron into a mold and allowing it to cool into a solid shell. Once formed, the interior is coated with porcelain enamel, which gives a smooth, glossy surface that resists scratches and stains.
Unlike flexible materials, cast iron bathtubs do not bend or shift under load. That rigidity is why they feel solid when you step in and why they hold up for decades. Many iron tubs installed generations ago are still in daily use. One reason people often compare cast iron tubs to concrete bathtubs is their long lifespan.
The downside is simple. Iron is heavy, which is the primary factor that influences where and how these tubs can be installed safely.
Cast Iron Tub Weight by Style
The style of the bathtub affects its weight. Clawfoot tubs, freestanding cast-iron tubs, drop-in models, and soaking tubs vary in design, depth, and wall thickness.
Clawfoot Cast Iron Tubs
Clawfoot bathtubs come with ornamental feet that support their weight. This design incorporates iron into the system, making the cast-iron tub heavier. The weight of the empty tub is between 300 and 400 lbs. The heat retention is rated excellent due to the thick walls and enamel coating. If you want to install such iron tubs, you may need extra floor support on upper levels.
Freestanding Cast Iron Tubs
Freestanding tubs directly rest on the floor. They may not have decorative feet, but the base is reinforced for support. The empty tub weighs around 280–420 lbs and has a relatively small footprint, which is a significant advantage for small bathrooms. If you are looking for this type, you need to ensure that you follow safety precautions as well. You need to plan for floor reinforcement so that the total weight can be safely supported.
Drop-In Cast Iron Tubs
Drop-in cast-iron tubs are designed to be installed on a framed deck, so their exteriors are not fully finished. This is comparatively lighter than clawfoot or freestanding iron tubs. They weigh around 200–300 lbs, and installation complexity is moderate, since the neighboring deck contributes stability to the installation. Cleaning is easy!
Cast Iron Soaking Tubs
The heaviest of all, cast iron soaking tubs, weigh between 320 and 500 lbs. These tubs are deeper and can therefore hold more water, increasing their overall weight. This type features superior heat retention, as these tubs can keep hot water hotter longer than an acrylic bathtub. From a design perspective, it is an excellent choice for both long soaks and luxury bathrooms.
Believe your weights are about 100 lbs high. The 72” clawfoot tub in the photo on this write-up weights 300 lbs, and it is a large tub. I suggest taking all the weights down by 100 lbs.
| Tub Style | Empty Tub Weight (lbs) |
|---|---|
| Clawfoot Cast Iron Tubs | 300–400 |
| Freestanding Cast Iron Tubs | 280–420 |
| Drop-In Cast Iron Tubs | 200–300 |
| Cast Iron Soaking Tubs | 320–500 |
Cast Iron Tub Weight by Size
Tub size plays a major role in determining overall weight, installation requirements, and floor support needs. Even small increases in length or depth can significantly change a cast-iron tub's weight and handling.
Cast Iron Tub Weight by Size
When it comes to a cast iron tub, size is an essential factor not only for aesthetics and comfort but also for weight. Iron is heavy, and if a tub is larger or deeper, it requires more iron, which increases the maintenance cost. Hence, even a slight change in measurement can add up to pounds with them and directly affect installation, floor support, and handling.
55"–60" Inch Cast Iron Tub Weight
The 55"–60" range is perhaps the most common size for modern renovations. These tubs generally weigh 200–320 pounds when empty. They strike a balance between comfort and practicality. This size works well as either a freestanding or an alcove cast iron tub, offering flexibility depending on your layout. iron bathtub
Even though the weight is manageable, it’s still essential to plan your installation carefully. If you’re placing it on an upper level, it's recommended to check the floor joists for adequate support to prevent sagging or long-term damage.
61"–66" Inch Cast Iron Tub Weight
Weighing between 280 and 420 pounds when empty, tubs in the 61-inch to 66-inch size range offer a luxurious look. These tubs often boast deeper soak designs, making them perfect for spa-like experiences at home. Because of the extra material, installation on elevated floor levels requires careful assessment of floor support and reinforcement.
If you perform an inferior installation, a large size carries a significant risk of floor sagging. Experts should ideally handle these heavy tubs, especially on the first floor. The steeper slope aids heat retention and keeps the warm water bath comfier for slightly longer, which is why many homeowners will invest in a larger size.
67"–72" Inch Cast Iron Tub Weight
At the top end of the spectrum, tubs measuring 67–72 inches are actual statement pieces. These include vintage cast-iron tubs, deep-soaking options, and custom designs. The empty tub weight can range anywhere from 350 to 550 pounds, depending on the style and enamel thickness. The disadvantage is that these tubs are so heavy that shipping and installation become complex.
You need professional movers or multiple people to handle these tubs. Plus, you need extra floor support or structural evaluation, especially if you are installing them on upper floors. The advantage is unmatched durability, incredible heat retention, and the classic aesthetic appeal of a substantial clawfoot tub or a large freestanding cast-iron model.
| Tub Size (Inch) | Empty Tub Weight (lbs) |
|---|---|
| 55–60 | 200–320 |
| 61–66 | 280–420 |
| 67–72 | 300–500 |
Cast Iron vs. Other Bathtub Materials: What’s the Difference?
Appearance is not the only factor in selecting the best bathtub material. It will have a considerable impact on the bathtub's weight, installation difficulty, and lifespan, among other factors. By comparing cast iron with other popular materials, such as acrylic or copper bathtubs, you can determine what you are actually committing to before taking the plunge.
Cast Iron vs Acrylic Tubs
Acrylic bathtubs weigh less and are thus simple to transport. They cannot compete with cast-iron tubs in terms of heat retention, but they are less expensive, and their installation is relatively easy.
| Feature | Cast Iron Tub | Acrylic Tub |
|---|---|---|
| Weight | 400–550 lbs | 50–100 lbs |
| Durability | Very high | Moderate |
| Installation | Complex | Easy |
| Heat Retention | Excellent | Moderate |
| Design Variety | Moderate | Wide |
| Cost | High | Moderate |
Cast Iron vs Steel Tubs
Enameled steel tubs are lighter than iron bathtubs and heat water quickly but lose warmth faster.
| Feature | Cast Iron Tub | Steel Tub |
|---|---|---|
| Weight | 300–500 lbs | 70–120 lbs |
| Durability | Long-lasting | Moderate |
| Installation | Difficult | Easier |
| Heat Retention | Retains heat longer | Poor |
| Design Variety | Classic | Moderate |
| Cost | High | Low |
Cast Iron vs Stone Resin Tubs
Stone resin bathtubs are heavy, like iron, but can be brittle and require careful handling. Cast iron and resin tubs do not need additional floor supports. Think about the weight of a refrigerator; it is more lbs per square inch than a tub. Also think about the days of waterbeds, they didnt have extra support.
| Feature | Cast Iron Tub | Stone Resin Tub |
|---|---|---|
| Weight | 300–500 lbs | 300–500 lbs |
| Durability | Excellent | Very good |
| Installation | Not needed | Not needed |
| Heat Retention | Excellent | Good |
| Design Variety | Classic | Modern |
| Cost | High | High |
Do You Need Floor Reinforcement for a Cast Iron Tub?
No, floor reinforcement is not required. Cast-iron bathtubs can be safely installed on standard residential floors when installed in accordance with the manufacturer’s guidelines. On ground-floor concrete slabs, no additional support is needed. Even on upper floors, properly designed residential structures are typically capable of supporting the load without extra reinforcement. Ensuring correct installation and weight distribution is sufficient to prevent long-term issues such as sagging or damage.
How to Safely Move and Install a Cast Iron Tub
Moving a standard cast-iron tub requires proper equipment:
- Safety gear, including gloves and long sleeves
- Use a drop cloth to protect floors
- Lift with multiple people or dollies
- Avoid harsh chemicals during cleaning. Try mild dish soap or a mix of warm water and baking soda.
- Tools like an angle grinder or a reciprocating saw may be needed to remove an old bathtub.
- Even freestanding tubs require careful planning to avoid injury or damage
Final Thoughts
Most cast-iron bathtubs weigh a lot because of their structure and coating. Their heaviness plays a role in installation, transportation, and longevity.
In a bathroom remodel, knowing the weight is a safety factor and helps select the appropriate tub for your area. Adequate planning, such as floor strengthening, will ensure many years of pleasant bathing with minimal maintenance. Plan carefully to choose the tub that best meets your needs.
Frequently Asked Questions About Cast Iron Tub Weight
How Heavy Is a Clawfoot Cast Iron Tub?
The weight of most clawfoot tubs ranges from 300 to 400 pounds when empty, depending on their size, depth, and design style.
What Is the Best Way to Remove an Iron Bathtub?
The safest way is to drain the tub, disconnect the plumbing, protect the floors, use helpers or professionals, and remove it carefully to avoid injury.
Can I Install a Cast Iron Tub on the Second Floor?
Yes, you can install most cast-iron tubs on the second floor, but only after discussing floor joists, load capacity, and possible reinforcement with a professional contractor.
How Much Does a Cast Iron Tub Weigh When Full?
The weight of a filled cast-iron tub can be as much as 650-900 pounds. This includes the water and the bather's weight, and it will also vary by tub size.
