People have been installing cast iron bathtubs in their homes since the late 19th century, and they’re still prevalent today due to their durability, ability to retain heat, resistance to chipping, and classic look. They require little maintenance, they’ll last forever, and they’re an excellent investment for any home.
Besides being more expensive than other bathtub materials, cast iron has one major downside; it’s extremely heavy. If you plan on installing a cast iron bathtub in an upstairs bathroom, you need to ensure that your floor can support its weight.
So how much do cast iron bathtubs actually weigh?
Cast iron bathtubs typically weigh between 240 and 500 pounds; however, the actual weight depends on the size and type of bathtub.
- Alcove cast iron bathtubs are usually 60 inches long, hold 32 gallons of water, and weigh 320 pounds on average.
- Freestanding cast iron bathtubs are 60 to 75 inches long, hold up to 82 gallons of water, and weigh an average of 385 pounds; however, large ones can weigh up to 500 pounds.
- Petite freestanding cast iron bathtubs are 45 to 55 inches long, hold 32 gallons of water, and weigh 250 pounds on average.
I’m assuming that you’re reading this article because you’re trying to determine whether your floor is strong enough to support the weight of a cast iron bathtub. If that’s the case, you need to consider the weight of the bathtub plus the weight of the water and the people that will be bathing in it.
Since water weighs 8.34 pounds per gallon, the average 32-gallon bathtub can hold up to 267 pounds of water. If you buy a standard 320-pound, 32-gallon cast iron bathtub, your floor needs to be able to support at least 587 pounds (bathtub weight 320 lbs. + water weight 267 lbs.) plus the weight of the heaviest person that will be using it.
As a general rule, bathroom floors that are built in compliance with today’s residential building code have a live load of 40 pounds per square foot. For example, a bathroom that’s 5 feet wide and 10 feet long can or support up to 2000 pounds. More on this calculation in a minute (skip right to it).
In the following sections of this article, I provide 15 examples of popular cast iron bathtubs and reveal to you exactly how much they weigh when they’re empty and when they’re filled with water and people.
I also explain how to determine if your floor is strong enough to support a cast iron bathtub and provide answers to the most common questions that homeowners who are thinking about installing a cast iron bathtub ask.
Use the links below to jump to a section.
- How Much Do Cast Iron Bathtubs Weigh? (15 Examples)
- How Much Weight Can Your Bathroom Floor Support?
- How Much Do Porcelain-Enameled Steel, Fiberglass, and Acrylic Bathtubs Weigh?
- Frequently Asked Questions About Cast Iron Bathtubs
You already know that cast iron bathtubs are extremely heavy, but how much do they weigh exactly?
In the chart below, you’ll find 15 of the most popular cast iron bathtubs compared by empty weight, total weight, length, and type.
(Swipe left and right to view the entire chart)
|Tub||Empty Weight (lbs)||Total Weight (lbs)||Length (inches)||Water Capacity (gallons)||Type||Check Price|
|Pegasus Claw Feet Tub||247||738||55.5||36||Freestanding||HomeDepot.com|
|KOHLER Seaforth Tub||277||743||54||33||Alcove||HomeDepot.com|
|Aqua Eden Clawfoot Tub||280||805||61.4||40||Freestanding||HomeDepot.com|
|KOHLER Memoirs Tub||350||816||60||33||Alcove||HomeDepot.com|
|KOHLER Dynametric Tub||345||828||60||35||Alcove||HomeDepot.com|
|Aqua Eden Petite Clawfoot Tub||250||841||54||48||Freestanding||HomeDepot.com|
|Barclay Products Wooden Feet Tub||260||910||67||55||Freestanding||HomeDepot.com|
|Barclay Products Lion Paw Feet Tub||364||914||71||43||Freestanding||HomeDepot.com|
|Barclay Products Roll Top Tub||350||1000||67.75||55||Freestanding||HomeDepot.com|
|KOHLER Iron Works Tub||375||1100||66||64||Freestanding||HomeDepot.com|
|Aqua Eden Pedestal Tub||492||1283||72||72||Freestanding||HomeDepot.com|
|KOHLER Vintage Tub||485||1360||72||82||Freestanding||HomeDepot.com|
Some quick things about the data to note:
- I pulled the specs for each bathtub from each manufacturers’ website. You might find some very insignificant differences in their weight on other websites, but you can rest assured knowing that the numbers in the chart above are official.
- Total Weight includes the weight of the empty bathtub, the weight of the water (each gallon weighs 8.34 pounds), and the weight of the average American male (191 pounds). This metric is meant to give you a general idea of what the total weight could be, but you’ll have to adjust the calculation to fit your circumstance.
- Alcove bathtubs are the most common type of bathtub. They are situated between three walls with one side open to allow you to get in and out. They are usually only finished on the one open side.
- Freestanding bathtubs are finished on all sides installed away from walls, on their own. Freestanding bathtubs are mostly installed in large master bathrooms that have separate stand-up showers. The classic clawfoot bathtub is a type of freestanding bathtub with fancy vintage feet.
Now that you understand how much cast iron bathtubs weigh based on size and type, it’s time to determine if your floor can handle the weight.
If you’re planning to install your bathtub on the ground floor with a concrete foundation, you have nothing to worry about. If you’re planning to install your bathtub upstairs or on a floor supported by wooden floor joists, it’s wise to make sure the bathtub you choose isn’t too heavy.
Homebuilders in the United States are required to follow residential building codes, which outline the maximum spacing between floor joists. In most homes, the floor joists are 16 inches apart but, depending on the type of wood, the spacing can go up to 24 inches.
As long as your house is up to code, the maximum live load of your floor is 40 pounds per square foot (psf). The live load is the amount of weight, in pounds, that your floor can safely handle, including people, furniture, and anything else that will be placed on top of the floor.
This means that your bathroom floor can safely handle up to 40 multiplied by the square feet of the room in pounds. For example, if the dimensions of your bathroom are 5 by 10 feet, the floor can hold up to 2000 pounds (40 x 5 x 10). If your bathroom is much larger, say 10 by 10 feet, it could hold up to 4000 pounds (40 x 10 x 10).
Although nothing else in your bathroom should weigh as much as a cast iron bathtub, you need to factor in the weight of the other items (toilet, vanity, etc.) when determining if your floor is strong enough for the cast iron bathtub you’re considering.
If you’re worried that your floor isn’t strong enough to support the weight of a cast iron bathtub, don’t take a chance. Get in touch with a local contractor (I highly recommend getting free quotes on HomeAdvisor if you don’t already have a contractor) and have them take a look. If the floor isn’t strong enough, the contractor can reinforce the floor with new floorboards or install additional floor joists beneath the floor.
If the weight (or price tag) of cast iron bathtubs scare you, you might want to consider a steel, fiberglass, or acrylic bathtub. All three materials are lighter in weight and significantly less expensive than cast iron. The downside of these materials is that they’re not as durable, don’t feel as stable, and don’t retain heat as well. Also, in the case of steel bathtubs, the steel can rust if the external porcelain coating chips or cracks.
Let’s take a look at how steel, fiberglass, and acrylic bathtubs compare to cast iron in terms of weight.
A standard 60-inch porcelain-enameled steel bathtub weighs about 75 pounds. Below are a few examples:
- Bootz Industries Bootzcast Alcove Bathtub: 90 pounds (view on Amazon)
- Bootz Industries Aloha Alcove Bathtub: 67 pounds (view on HomeDepot.com)
- Bootz Industries Maui Alcove Bathtub: 74 pounds (view on HomeDepot.com)
Fiberglass bathtubs are significantly lighter than cast iron bathtubs, and they’re also less expensive. A standard 60-inch fiberglass bathtub weighs 80 pounds. Below are a few examples:
- Sterling Accord Alcove Bathtub: 82.5 pounds (view on HomeDepot.com)
- Sterling Ensemble Alcove Bathtub: 87 pounds (view on HomeDepot.com)
- Swan Alcove Bathtub: 70 pounds (view on HomeDepot.com)
Acrylic bathtubs are very popular because they’re easy to maintain, affordable, and lightweight. A standard 60-inch acrylic bathtub weighs 109 pounds. Below are a couple of examples:
- Kingston Brass Acrylic Alcove Bathtub: 83.6 pounds (view on Amazon)
- FerdY Acrylic Freestanding Bathtub: 92.6 pounds (view on Amazon)
If you are seriously considering a cast iron bathtub for your home, you might have some other questions besides “what does it weigh?”. Here are answers to the most common questions about cast iron bathtubs.
Can cast iron bathtubs be recycled? Cast iron bathtubs are not the type of item that you can leave on the side of the road for your recycling company to come to pick up; however, if you need to get rid of one, you have several options. If the tub is in bad shape, one option is to take it to a scrapyard. According to FirstQuarterFinance.com, the average scrap price for cast iron is around $.09 per pound. If it’s in good shape, you’re better off trying to sell it on Craiglist, eBay, or Facebook. If none of those options are appealing, make an appointment for 1-800-JUNK to come and pick it up. They’ll charge you a fee, but they’ll go right into your bathroom and take it away, and you won’t have to break your back trying to get it out of your house.
Can cast iron bathtubs be painted? Since cast iron bathtubs are so durable and long-lasting, you might find yourself in a situation where you’re inheriting or buying an old tub that could use some sprucing. If the external layer is fading or rundown, you can refresh it with a new coat of paint; however, you need to follow the proper steps and use the right type of paint. If you plan to do it yourself, this step-by-step guide from WikiHow is a great place to start. If these steps are too intimidating, you can always hire a professional painter to do the job.
Can cast iron bathtubs be broken up? Yes, if you’re remodeling a bathroom and need to remove an unwanted cast iron bathtub, you can break into pieces. The best tool to use is a sledgehammer.
Can the porcelain enamel on cast iron bathtubs chip? The enamel coating on cast iron bathtubs is exceptionally resistant to chipping, but if you drop something heavy or sharp onto it, there’s a possibility it will chip. Fortunately, it’s easy to fix chips with very inexpensive products like the Magic Porcelain 2 Part Epoxy Chip Fix.
Who can I hire to install a cast iron bathtub? When you buy a cast iron bathtub from HomeDepot, they offer professional installation as an additional service. However, if you buy a bathtub online or from a store that doesn’t provide an installation package, you’ll have to hire a local plumber to install it. The cost of installation will range from $1000 to $4,500 depending on where you live, the type of bathtub, and the modifications you need. You can get quotes from plumbers in your area for free on HomeAdvisor.com.
We want to hear from you! Do you own a cast iron bathtub? Do you prefer cast iron over the other lighter, cheaper materials? Are cast iron bathtubs worth it? Let us know in the comments below.
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