The cast iron bathtub has remained a popular choice since it was first introduced in the early 19th century. Cast iron bathtubs are still among the most popular bathroom choices thanks to their classic and aesthetic look, excellent durability, and heat retention ability.
However, these bathtubs are heavyweight, in fact, the heaviest. Thus, you need to consider the weight retaining ability of the bathroom floor before selecting a cast iron tub. It means knowing ‘How much does a cast iron bathtub weight?” is your primary concern for its installation.
An average bathtub made of cast iron may weight somewhere around 300 pounds. However, its size, wall thickness, and model type will determine its weight largely.
Today we will discuss the average weight, benefits, and setbacks of the cast iron bathtub to help you make a prompt decision.
Cast Iron Bathtub History
The history of cast iron bathtubs can be dated back to the early 1880s. Inventor David Buick was the first to introduce these bathtubs at the then bathroom as part of a classic interior. He bonded the cast iron with porcelain enamel for the aspiring and aesthetic look inside the bathroom.
Cast iron has a low melting point. So, manufacturers can mold it into any shape, which inspired them to use the alloy-carbon element in their bathtubs. You will find the cast iron bathtubs mostly in clawfoot and freestanding models.
However, these bathtubs are also available in different shapes, thanks to their easy molding facility. Also, once installed, the cast iron tubs will ensure long-lasting service life.
How Much Does A Cast Iron Bathtub Weight?
Thanks to the durability and medieval look, a cast iron bathtub is an attractive choice for most homeowners. However, their main concern is the weight of the cast iron tub. And it is valid as these tubs are the heaviest of all.
An average cast iron bathtub will weight anywhere from 240 pounds to 500 pounds. It is a serious weight that your bathroom floor will need to carry every day. Nonetheless, the weight of the empty cast iron tub depends mainly on its size, shape, and cast iron thickness. And when it is full, you have to count the weight of the water too.
- Alcove bathtubs are pretty popular. Its length is 55-inch and, holds up to 32 gallons of water, and weighs up to 300 pounds.
- Freestanding bathtubs are among the heaviest ones weighing right up to 500 pounds with the larger variants. The average freestanding bathtub weight is 375-400 pounds. Its size varies from 60 to 75-inch.
- Kohler has multiple cast iron bathtub models. Their Seaforth model weighs up to 277 pounds, and its size is 54-inch. It holds up to 33 gallons of water.
How Much Water Does An Average Cast Iron Bathtub Hold?
When we talk about bathtub weight, we often refer to cast iron bathtub empty weight. Well, it is a tricky answer since the weight of the water will also put pressure on your bathroom floor in addition to the bathtub.
So, you need to calculate the water holding capacity of the bathtub, its weight, and then you will get the actual weight of the cast iron tub when not empty.
One (1) gallon of water weighs 8.32 pounds. It means a standard 32-gallon capacity bathtub will weigh around 267 pounds. Also, a freestanding 32-inch cast iron bathtub empty weighs 320 pounds. So, with water, its actual weight will be 587 pounds.
Below is the list of the most popular cast iron bathtub models with their empty and water-filled water.
Bathtub Model | Empty Weight (lbs) | Water Capacity | Water-filled Weight (lbs) |
Pegasus Claw Feet Tub | 247 | 36 | 738 |
KOHLER Bellwether | 310 | 32 | 768 |
Aqua Eden Clawfoot Tub | 280 | 40 | 805 |
KOHLER Dynametric Tub | 345 | 35 | 828 |
Barclay Products Roll Top Tub | 350 | 55 | 1000 |
You see that an average cast iron bathtub weight with water is well over 500 pounds. So, you measure your floor capacity before installing these tubs in your bathroom. Or else, it runs the risk of damaging the bathroom floor so badly that you may renovate it. And believe us, it can be costly.
So, here’s the answer to an important question.
How Much Weight Does Bathroom Floor Support?
You need to know the load capacity of the bathroom floor to install the cast iron bathtub properly. You can’t fix your bathtub model unless you know the floor capacity. Thankfully, expert home builders and interior designers have come with excellent suggestions for this purpose.
Ideally, a concrete floor will withstand the average weight of a bathtub with ease. So, you can confidently install any cast iron bathtub if your bathroom has a concrete floor. But the same thing can’t be said for wooden-floored bathrooms.
Ideally, you should choose a moderate weighing cast iron tub for the wooden bathroom floor. The same goes for upstairs bathroom tub installation.
The best practice is to follow the building codes for floors. According to the floor codes, the bathroom floor can easily accommodate 40 square feet per foot (SPF). Keeping this in mind, you have to measure the total floor space of the bathroom and then determine whether or not the floor can hold the cast iron tub weight.
For instance, if your bathroom is 10ft long and 7.5ft wide, its floor spacing will be 75 square feet. So, its actual load capacity will be around 3000 pounds. Well, it might prompt you to mount the heaviest tub in the bathroom. But you should consider the weight of your toile, basin, and other installations to finalize the tub model.
Nonetheless, choosing a moderate-weight bathtub is always the best practice, even if your bathroom floor is made with the strongest concrete. It will save you from any possible damage to the bathroom floor.
Benefits of Cast Iron Bathtub:
- Cast iron is amongst the most durable material. So, your bathtub will be nearly a permanent placement without any damages.
- Cast iron tubs offer a timeless classic look that never fades away from its aesthetics. It quickly elevates your bathroom decor.
- Cast iron is scratch and chip-resistant. Thus, you won’t need to worry about its maintenance. Its low maintenance is also a money-saving deal.
- These tubs are available in different shapes and styles. Thus, you are at liberty to choose your favorite style, shape, and color to match the bathroom décor.
The Setbacks of Cast Iron Bathtub:
- Since cast iron made bathtubs are heavyweight, they will need additional support. Also, it runs the risk of damaging the floor.
- These tubs are highly expensive. Thus, they aren’t pretty budget-friendly.
Final Words
So, how much does a cast iron bathtub weight? The average weight of a cast iron varies from 240 pounds to 300 pounds. While the heavyweight of the cast iron tubs is a major concern, the good news is most concrete floors can accommodate it with ease. On top of it, these tubs bring a classic medieval vibe to your bathroom décor. Also, its low maintenance and long-lasting performance add to the overall value of the cast iron bathtub.
I am James Martin, An professional plumber with more than 16 years of experience. The main purpose of my writing is to share my experiences of helping others. Be with me and explore bathroom plumbing, installation, cleanness ideas, and many more.