If your bathroom has existing roughed in sewage and water supply, it is not to difficult to add a toilet. This can be great if you want to use your basement as another living area.

Installing a toilet into rough in pipes in the basement will require making sure the pipes are cut to size. Then, flanges and shutoff valves will need to be installed for the drain and supply, respectively. Then, install the toilet.

Rough In Pipes

Rough in pipes are essentially unfinished plumbing outlets. They are fully ready to use but have nothing attached to them yet. Drains are, therefore, capped off to prevent sewer fumes.

Tools You Will Need

  • Hammer and hand drill with drill bits
  • Hacksaw
  • Open end wrench

Materials Required

  • Toilet
  • Toilet supply hose
  • Toilet flange (same material as your rough in pipe)
  • Adhesive to match your rough in material
  • Shut off valve
  • Concrete screws
  • Hammer
Install a Toilet in a Basement with a Rough In Pipe
Image Credit: TerryLove.Com

Locate Your Rough In Plumbing

Your rough in drain should not be difficult to find; it will be located about 12” to 14” from a wall. It will often stick out some distance from the floor and need to be cut down to allow for a toilet.

Your water supply pipes should be located against the wall and end about 9” above the floor. This should be behind the drain and a bit to the left.

Sometimes a flange may already be installed; if it is, check the height. Rough in piping is often installed before the house is fully completed. This may leave the flange too high or too low.

Too high just means cutting it down and installing a new flange. However, too low may require a toilet flange extender.


You will need to shut off your water supply before you begin. So check if you can turn off the water supply to your home. If not, in some homes, it will require your utility company to do it for you.

If you are planning to add other bathroom fixtures, this will require digging a trench to tie drainage lines into your toilet’s drain line. Also, you need to tie into the water supply, so if you wish to do this, you should consider doing this now.

Installing the Toilet Flange

To start your process, you will need to prepare the drain line for the toilet to be installed. Follow these steps.

  1. Inspect your drain pipe. Is it metal, PVC, or ABS? Depending on the material your drainpipe is made of, you will want to match your toilet flange to the existing material.
  2. Saw the drainpipe. You will want to saw the drainpipe down to floor level if it is not already there. Then, if it is, use a hammer to remove the cap. You may want to use a cloth rag to block sewer fumes.
  3. Line up the flange. You want two of the four holes in the flange to be equidistant from the wall so the toilet can be installed straight. Ensure the closet bolt holes are located on the sides where the toilet can be connected.
  4. Drill the flange and the floor. First, use a hand drill to prepare the holes in your new flange. Next, use a hammer drill to prepare holes in the concrete floor.
  5. Clean and prepare the drainpipe and toilet flange. You can use some fine-grit sandpaper for deburring both sides and a rag to clean both ends.
  6. Apply adhesive to both ends. Depending on the material, you will want to purchase an adhesive designed to fuse it. This may be ABS cement or others.
  7. Insert the flange. Ensure the flange and the interior of the drainpipe have received a good coating of adhesive and insert the flange. Then, use the concrete screws to affix the flange to the ground. You may want to caulk around the flange now.

Installing a Shutoff Valve

Your new toilet will need a water supply fitting with a shutoff valve. Installing this is not hard at all. Follow these steps.

  1. Turn your water supply off. Otherwise, you are in for a bath.
  2. Cut the end of the pipe. Leave enough room to install the supply valve. Then, deburr the end using some sandpaper or a deburring tool.
  3. Place a compression nut. Slide it onto the pipe and as far back as it will go.
  4. Place the compression ring. Make sure it fits well over the end of the supply pipe.
  5. Attach the compression valve. This is slid over the compression ring. Then, it is held by the compression nut.
  6. Tighten the compression nut. Tighten snugly using two wrenches, one for the nut and one to hold the compression valve.
  7. Ensure no leaks. Turn the compression valve off by turning clockwise until it stops. Then, turn the water supply on and inspect for leaks.

Install the Toilet

It is time to install the toilet. It is a good idea to have someone help you lift and line up the toilet. However, you can do it alone if needed. Follow these steps.

  1. Install the closet bolts. Install these through the wide opening and then slide them into the final position. If your set came with plastic clips to hold these in place, slide them on now.
  2. Install the flange seal. The flange seal can be wax. However, if you are installing the toilet alone, a waxless seal would be a good idea. This is best because the toilet can be installed incorrectly without ruining the seal.
  3. Set the tank on. Do this carefully and lift it over the closet bolts. The weight of your toilet is enough.; so, do not press down unnecessarily. You may wish to consider installing only the bowl and install the tank after this.
  4. Screw the nuts onto the closet bolts. These should be made snug with a wrench but do not overtighten. This may break the toilet bowl.
  5. Install the tank if needed. There should be two nuts and one seal. Install these and snug the nuts down with a wrench carefully.
  6. Connect the water supply. Connect this between the shutoff valve and the fill valve on the bottom of your toilet tank.
  7. Turn the water on. Check for leaks.

How Do You Cover Exposed Pipes in a Basement?

If you want to cover your exposed pipes to make your basement look better, there are several options. A few of these are listed below.

Covering the pipe. You could make the pipes look more decorative by covering them with rope, fabric, or even decorative tape.

Paint the pipes. Painting your pipes can also make your basement look better. You could paint them to blend in or paint them to stand out decoratively. You have a large variety of colors and designs to choose from.

Hide the pipes. You could hide the pipes by putting screens around them or building a box to cover them.

Does a Basement Bathroom Need a Fan?

This varies according to where you live. Some municipalities require fans, and some don’t. However, whether a fan is required or not, it is definitely useful for controlling moisture and odors.