How to Break Up a Cast-Iron Tub

If your bathroom remodeling plans call for a new bathtub, you may be wondering how you're going to get that old cast-iron one out of the bathroom. Weighing in at 300 pounds, it's far too heavy to gracefully lift out of its alcove and maneuver through the door and down the stairs. The answer is to break it up with a sledgehammer. Cast-iron is brittle, and several well-placed whacks with a heavy sledgehammer will shatter it into manageable pieces. This is a messy job, but it gets the old tub out without sacrificing anyone's back or knees.

If you're getting rid of your cast-iron tub, there's no reason to be dainty about it.

Step 1

Turn off the water to the tub, open the faucets and let the water drain. Cut the water pipes with a reciprocating saw. Unscrew the faucet from the side of the tub with a wrench and remove it. You should also remove enough drywall from the walls to which the tub is attached to expose the tub flanges.

Step 2

Go underneath the tub and cut through the P-trap to disconnect the tub from the drain. Unscrew and remove the drain. If the tub has a trip lever for a pop-up stopper, go back upstairs, unscrew the lever cover from the side of the tub with a screwdriver and pull out the linkage.

Step 3

Cover the tub with a moving blanket. This prevents shards of metal from flying around the room and injuring someone. Put on a pair of goggles and protective gloves and get your 20-pound sledgehammer out of the tool shed. If you only have a mini-sledge, rent a full-sized one -- you'll need the extra weight.

Step 4

Strike the first blow on the side of the tub. If the metal doesn't shatter, keep swinging until it does. Move over to the other side of the tub and strike the inside of it until the metal on this side shatters. Strike the bottom of the tub next -- the tub should crack and split in two.

Step 5

Break each of the sections into two pieces by striking the ends of the tub until the metal shatters and then hitting the bottom of the tub. Once the tub is broken into four pieces, you should be able to haul it away.


  • Once the metal shatters, the edges are sharp. Wear protective gloves when handling both large and small pieces of the tub.

About the Author

Chris Deziel has a bachelor's degree in physics and a master's degree in humanities. Besides having an abiding interest in popular science, Deziel has been active in the building and home design trades since 1975. As a landscape builder, he helped establish two gardening companies.