While a lot of DIY home renovation activities may seem like you, the homeowner can go the whole distance without having to call a professional, others seem difficult and daunting. One of those seemingly overwhelming activities is removing an old cast iron bathtub while renovating your bathroom.

While removing an old bathtub, and a cast-iron one at that, may seem like a lot of work for a greenhorn homeowner to do, we’re going to show you how you can do just that. 

Is the tub cast iron?

Before you begin dismantling your bathtub, you may want to make sure that it is indeed a cast-iron one. Here are three easy ways to determine whether your tub is cast iron or not.

Knock on it

The easiest way to check what your bathtub is made of is o knock on it. An acrylic tub will make a hollow sound, while a steel one will have a sharp, metallic ring to it. Cast iron tubs will make a deep, gong-like sound when knocked on.

Look underneath

If it is possible, look underneath the tub. Cast iron tubs will be completely black underneath, while acrylic tubs will be painted and steel tubs are metallic.

Ask around

If you live in a housing complex, ask your neighbors who have been there longer than you. Chances are, most bathroom fittings were put in at the same time and are similar in design and quality. They ought to be able to tell you what the bathtubs are made of.

The process

Once you’ve determined that your bathtub is indeed made of cast iron, here’s a list of the tools and materials you will need to remove it.

Tools and materials 

  • A reciprocating saw or a Sawzall
  • Safety gloves
  • Safety goggles
  • Utility knife
  • Pipe wrench
  • Flathead screwdriver
  • Needle-nose plier or similar tool to remove drain flange
  • Angle grinder
  • Hammer
  • Heat gun
  • Hammer
  • Plywood sheet
  • 16 lb sledgehammer

The process

Disconnect the drainage

cast iron tub drain
  1. The first thing you need to do is turn off the water supply to the bathtub. If your tub is a free-standing one or one that you can access from all four sides, you ought to find the shut-off valve connected to the water line that supplies the tub’s faucets. 

Other models may need you to turn off the water supply to the home entirely or there may be knobs behind the toilet. Either way, check and make sure that the water supply is indeed switched off before proceeding.

  1. Next, you will need to remove the overflow assembly and the stopper. The overflow plate is connected to the tub by one or two screws that hold the stopper level in place. Use the screwdriver to remove these. This should allow you to remove the stopper by simply tugging on it.
  2. The next thing you need to do is use the needle-nosed pliers to grip the drain flange. This is found at the bottom of the tub. Once you have a firm grip on it, turn it counterclockwise and yank it out.
  3. Finally, you will need to remove the drainpipe from the tub. If your tub is free-standing, simply use a Sawzall and a metal blade to cut off the drainpipe about two or three inches away from the bottom of the tub.

If the tub is attached to your home, you will need to access the bottom from a crawl space or basement and use a pipe wrench to dislodge the pipe.

Dislodge the tub

  1. If your tub is attached to the wall, carefully cut through the wall around 6 inches above the tub. Take care to make sure not to damage any plumbing, studs, or wiring inside the wall.

If you have tiles on the wall, you will need to use an angle grinder to cut through the routing and then individually remove each tile by using a chisel to pry it out.

These steps are obviously not needed for a freestanding tub.

  1. Next, locate the nails or screws that attach the bathtub to the studs. Use the claw of a hammer to pry them off the studs.
  2. Next, apply caulk remover wherever caulk has been used, on the sides and in some cases, at the bottom of the tub. Wait for the caulk to soften and then use the utility knife to peel it off.
  3. If the caulk is stubborn in places, use a heat gun to soften it before peeling it off. However, be careful and make sure you don’t heat any plastics and other materials around the area. Any debris can be removed using a toothbrush.
  4. Lay the plywood sheet on a clear area of the floor. Then, using the help of a partner or a friend, carefully move the tub onto the plywood sheet. The average cast iron bathtub weighs around 300 pounds, so it definitely is not a one-man job.

The plywood sheet is to make sure you do not damage the bathroom floor while moving the tub.

Read more: How much is bath fitter

Dispose of the tub

  1. Well-maintained cast iron tubs have a lot of buyers in the second-hand market, especially the ones with ornate legs on them. So if you have a buyer, all you need to do now is figure out how to ship it out to the new address.
  2. If you need to dispose of the tub, you will need to break it down into smaller pieces that can be carted off easily. Cover the tub with a heavy blanket or cloth. Then, wear protective goggles and glasses, bring out the 16 lb sledgehammer and get to work pounding the tub into smaller pieces. For best results, use the reciprocal saw and the sledgehammer.
  3. Once the tub has been broken down, put the pieces into garbage bags marked as “Concrete” to help disposal workers and keep it ready for disposal.
Bathroom renovations: How to remove a cast iron tub was last modified: October 20th, 2022 by Narayan Shrouthy
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Very Informative post & insightful. An Angle Grinder is a very powerful tool. Any kinds of metal can be cut with it.