If you are redoing your bathroom, you may want your new shower to lay over the old location of your toilet. If that is the case, you’re in luck. You can turn a toilet drain into a shower drain by reducing the drain size from 4-inches to 2-inches. 

To learn how to turn a toilet drain into a shower drain, read on. In this guide, we cover the steps for turning a toilet drain into a shower drain and even answer frequently asked questions for your convenience. Let’s get started. 

Yes. You can turn a toilet drain into a shower drain. All you will need to do to turn a toilet drain into a shower drain is to reduce the 4-inch PVC toilet drain into a 2-inch drain for the shower. 

Doing so will require either access from a basement or crawlspace or for you to cut away some subflooring surrounding the drain. 

How To Turn A Toilet Drain Into A Shower Drain 

Turning a toilet drain into a shower drain can be difficult, and it requires several tools and steps to accomplish. If you are not experienced at working with drains, it is recommended to hire a professional so that you don’t cause costly damage to your pipes or flooring. 

What You Will Need 

Here’s what you’ll need to turn a toilet drain into a shower drain: 

  • Adjustable wrench 
  • Flat pry bar
  • 4-inch to 2-inch PVC reducer
  • PVC primer and cement 
  • 1.4-inch screws
  • Plywood 
  • Putty knife
  • Stud finder
  • PVC pipe
  • Torpedo level 
  • Shower drain kit
  • Pipe strap 
  • Chisel 
  • Power drill with screw tip 
  • Reciprocating saw
  • 2-inch PVC trap 

Steps

Here are the steps for turning a toilet drain into a shower drain: 

Prepare Toilet 

The first step to turning a toilet drain into a shower drain is preparing the toilet. Begin by turning off the water supply and removing the supply tube with an adjustable wrench. Then, flush the toilet to remove most of the water, loosen the nuts on the closet bolts, and lift the toilet off the toilet flange. 

With the toilet removed, you should be looking at a toilet flange. Scrape away any of the wax ring left on the flange and loosen the mounting screws with a power drill. Remove the flange with a pry bar. 

Locate Toilet Plumbing 

Next, you will need to locate the toilet plumbing from beneath the floor. This step will be easier if you have access to a basement or crawlspace. Use the basement or crawlspace to locate the plumbing and then remove the subflooring around the drain. 

If you do not have a basement or crawlspace, locate the closest floor joist using a stud finder. Then, cut up the subfloor to the two floor joist with a reciprocating saw. This will give you access to the toilet’s plumbing beneath the floor. 

Prepare The Toilet Drain 

Now that you have the toilet plumbing located, you will need to prepare the toilet drain. Cut the toilet drain back to about 12 inches from the elbow using a reciprocating saw. This will be below the location of the old flange. 

Then, wipe off the burrs from the end of the remaining pipe and apply PVC primer to the end of the pipe and the inner edge of the PVC reducer. Put PVC cement around the pipe and connect the reducer to the pipe. 

Measure For The Shower Drain 

Now, it is time to start measuring for the shower drain. Measure the distance from the end of the reducer to the center of where you want the shower drain to be located. Then, subtract the distance from its length and add two inches to the total. Using the final number, cut a 2-inch PVC to match. 

Connect The Joint To The Reducer And The Trap To The Pipe

Next, connect the joint and the reducer as well as the drain end of the trap and the end of the pipe. Begin by applying PVC cleaner to the inside of the reducer and the outside of the pipe. Then, connect half of the joint using glue, and connect the pipe to the reducer. 

You will then connect the drain end of the trap to the end of the pipe using the same technique. 

Angle The Pipe

In order to make sure that water flows properly, you need to make sure that the pipe is angled correctly. You will do this by draining the PVC pipe with a torpedo level. Then, attach the pipe to the floor joist at a drop rate of ¼-inch per foot. This drop rate will allow the water to drain properly. 

Measure For The Flooring 

You also need to account for the flooring that will be put into the shower. Measure the distance from the top of the trap to where you expect the floor to lay. Then, subtract the height of the drain kit from the length of the distance. Cut another piece of 2-inch PVC to match. Prime and install the additional PVC to the end of the trap. 

Install PVC Base 

Now, install the PVC base by separating the shower drain. Then, install the PVC base to the short pipe with PVC primer and cement. 

Replace Subfloor

Finally, the last step for turning a toilet drain into a shower drain is replacing the subfloor. Simply chisel out the subfloor along each joist so that half of each joist can act as a nailer. Cut plywood to be the same thickness as the existing subfloor, and screw the plywood to the joists.

Install The Shower

Now that the toilet drain has been turned into a shower drain, you are free to install the shower over the drain and continue remodeling your bathroom. 

Frequently Asked Questions

How can I install a toilet once the old drain has been turned into a shower drain? 

Once you have turned the old toilet drain into a shower drain, you will need to install a new toilet drain for the new toilet. 

Overall, it is best to consult with a licensed plumber when installing a new toilet drain. The reason for this is that toilet plumbing is extremely complex and there are certain laws about safe plumbing and toilets. You do not want to attempt to install a completely new toilet if you have no expertise in the area. 

With that being said, you’ll need to install new waste and vent pipes and water supply pipes in order to completely move your toilet. 

Is it easier to install a shower using a toilet drain or creating a completely new drain? 

If you’re changing the location of your shower, it is easier to use the toilet drain instead of completely making a new drain for the shower. 

The reason for this is that the toilet drain will already provide much of the needed plumbing. Creating a completely new drain, however, will require more plumbing and tools as well as the need for a professional. Like toilet plumbing, shower plumbing can be difficult to add if you have no expertise in the area.