How to Remove a Cast Iron Tub

When it's time to install a new bathtub, it's also time to remove the old tub. Removal of a heavy, bulky cast iron tub isn't like removing an acrylic or fiberglass tub. Weight, bulkiness, and the possibility of damaging your walls and floors are formidable challenges.

But you've got three methods you can choose from that simplify removal and speed your way to the important task of remodeling your bathroom. You can either remove the cast iron bathtub in one piece or you have two options for breaking it up into small pieces. The solution depends on your needs and abilities.

Before You Begin

Reuse

If you need to keep the tub for some reason—for example, to reuse it in another part of the house or to sell it—you can try to remove it intact. It's not necessary to keep the tub in one piece for private debris haulers, as they take debris in nearly any condition. 

Weight

Lighter-weight modern freestanding cast iron clawfoot tubs weigh 250 to 300 pounds. Modern roll-top cast iron tubs can weigh 350 to 400 pounds. Some older cast iron bathtubs weigh 400 pounds or more.

The weight of cast iron bathtubs alone may prevent single-piece removal. Breaking up the tub with a sledgehammer makes it easier to remove since pieces are just a few pounds or less. Cutting up the bathtub with an angle grinder reduces carrying weight to 125 to 200 pounds per piece.

Accessibility

Modern freestanding clawfoot tubs are about 66 inches long, 36 inches wide, and 25 inches high. Slipper tubs raise the height another 6 inches, to 31 inches high. Standard alcove cast iron tubs are 60 inches long, 30 to 34 inches wide, and 20 to 22 inches high.

With most interior doorways ranging from 28 to 32 inches, moving intact bathtubs through doorways can be difficult. Doors and door casing can be removed to provide greater accessibility. Claw feet usually can be removed. 

Remove Tub Intact

Removing the cast iron tub intact means detaching the tub from the walls and floor, and moving it in one piece out of the bathroom through the door. 

Mess is kept to a minimum and the possibility of injury from sharp metal is reduced. 

Yet alcove bathtubs tend to fit so snugly in their bays that something has to give—either the walls or the tub. With this method, you may need to remove or shave down a wall stud or two to swing the tub out. 

With free-standing cast-iron tubs, carrying it out intact is the best way to go, unless doorway limitations preclude this.

Break up Tub With Sledgehammer

In this method, the cast-iron bathtub stays in place while taps from a sledgehammer methodically chip away the tub, so it can be removed in smaller pieces.

Breaking up the cast-iron bathtub with a sledgehammer is the preferred method for contractors and do-it-yourselfers alike. The tub can be reduced to pieces small enough to fit in contractor plastic bags. 

You'll need heavy gloves for this one, as the metal shards and chips of porcelain coating are razor-sharp. The sound is deafening, so hearing protection is required.

If you can handle the temporary mess, using a sledgehammer is the fastest way to break up and remove a cast iron tub.

Cut up Tub With Angle Grinder

An angle grinder fitted with a metal-cutting blade can cut through a metal bathtub, halving it for easier removal from the alcove and out of the bathroom. Because cutting is difficult, it's best to simply cut the tub once, either widthwise or lengthwise. Cutting it into many pieces takes too long.

The angle grinder produces glowing-hot metal shavings, but overall it's a fairly clean operation. Unlike the thousands of sharp metal pieces with the sledgehammer method, you only have two to deal with here. The tub's thick metal dulls blades quickly, and the job is extremely loud and requires patience and time. Plus, the two resulting pieces are still heavy—just not as incredibly heavy as a full-size tub.

When to Remove a Cast Iron Tub

When bathroom remodeling, remove alcove cast iron tubs after the tub's wall surround has been removed. This gives you access to any screws or nails on the tub's upper flange. Typically, the wall surround rests over the flange.

Since removing a cast iron tub is so messy and may damage the bathroom walls and floor, do this project before any finish surfaces are installed.

Safety Considerations

Wear safety glasses when removing the tub. When using the sledgehammer or angle grinder, wear hearing protection.

Protect yourself from the sharp metal with leather or other thick gloves, long sleeves, pants, and work boots.

When removing an intact cast iron tub, weight and bulkiness make this a job not just for two strong people but as many as three or even four. 

When shaving down or removing wall studs in order to remove an intact alcove tub, ensure that this is not a load-bearing wall.