How to Install a Shower/Bathtub

installing bath tub and shower
  • Advanced
  • 500-5,000
What You'll Need
Pipes (either existing plumbing or new piping)
Shower head
Mixing valve
Air chambers
Drywall materials
Silicone sealant

These installation procedures for your shower tub should allow you to tie into your present drain, waste vent, and supply systems. Once all the roughing in has been completed, you’re ready to assemble your shower and bathtub.

Step 1 - Install Piping Before Tub

You will be using your existing drain and waste vent system, but pipes required include the hot and cold water supply lines and a pipe leading to a shower head. A mixing valve and shower head are also needed. Air chambers may be required.

Step 2 - Position the Tub

Lower the tub into place so that the continuous flange fits against the wall studs and rests on 1'x4' or 2'x4' supports. Anchor the tub to the enclosure with nails or screws inserted through the flanges into the studs.

NOTE: Remember, bathtubs and shower stalls may require support framing. A bathtub filled with water is extremely heavy, so check building codes and framing support before installing the tub.

Step 3 - Assemble Drain Connections

Assemble the bathtub drain connections by connecting the tub overflow with the tub drain above the trap, not beyond it. The trap will have a compression fitting that screws over the arm of the overflow assembly.

Step 4 - Place a Pipe For the Shower Head

Locate a brass female threaded winged fitting and attach it to the framing support via a screw or a nail. Then run a pipe up the wall for the showerhead. Sweat or solder the other side of the brass fitting to the top of the pipe.

Step 5 - Attach Hot and Cold Water Lines

Attach your water lines for both hot and cold by sweating these directly into the hot and cold ports of the mixing valve. The mixing valve will be how water enters the tub’s system, not by the pipes themselves.

Step 6 - Install the Spout

Extend a piece of 1/2 inch pipe, or whichever length is specified in the manufacturer's instructions, for the tub spout. Sweat on a male threaded fitting at the end of the pipe or use a brass nipple of the proper length and a 1/2 inch cap.

NOTE: At this point you should have your rough-in plumbing work inspected before proceeding further.

Step 7 - Check For Leaks

Restore the water pressure and check the drain connection and the supply pipes for any sign of leaking.

Step 8 - Restore the Bathroom Wall

Replace the wall with moisture-resistant drywall as a base for your wall covering. Seal the joints between the wall and your new tub with silicone caulk as protection against water seepage.

Step 9 - Install the Shower and Tub Fixtures

The spout, handles, and shower head are all easily attached at this stage. You can usually screw them on to structures you’ve already put in place. For example, the shower head screws onto the shower arm stub out.

Step 10 - Prevent Future Leaks

Whether installing a new shower head or replacing an old one, always clean the pipe threads. Apply new pipe joint compound, PTFE tape, or both to prevent leaks.