Installing a bathtub faucet with a shower (tub-and-shower set) involves setting a mixing valve, connecting the tub spout, adding a shower riser and head, and finishing with trim. Accuracy during rough-in and leak testing are critical for safety and long-term reliability.

Before You Begin: What to Confirm

• Valve type: Use a tub/shower mixing valve (pressure-balance or thermostatic, as required by code).

• Wall access: Best from behind the tub (closet or access panel).

• Finished wall thickness: Backer board + tile + adhesive must be known.

• Code compliance: Many areas require anti-scald protection for showers.

Tools and Materials

• Adjustable wrench, pipe wrench

• Screwdrivers, Allen key

• Pipe cutter (copper/steel) or PEX tools

• Level, measuring tape

• Teflon tape, plumber’s grease

• Silicone sealant

• Tub/shower mixing valve

• Tub spout (with diverter)

• Shower riser pipe, shower arm, shower head

• Test caps/plugs

Step 1: Shut Off Water and Prepare the Wall

• Turn off the main water supply.

• Open existing valves to relieve pressure.

• Open the wall behind the tub if needed and remove old fixtures/valve.

Step 2: Install the Tub/Shower Mixing Valve

• Mount the valve securely to blocking between studs.

• Orient correctly:

• Hot inlet left

• Cold inlet right

• Bottom outlet to tub spout

• Top outlet to shower riser

• Set the rough-in depth to match the finished wall (most common mistake if wrong).

Step 3: Connect Water Supply Lines

• Run hot and cold lines to the valve.

• Support pipes to prevent movement.

• Tighten fittings securely—do not overtighten.

Step 4: Install the Tub Spout Drop

• Run a straight drop from the valve’s bottom outlet to the tub spout outlet.

• Keep this section short and straight (important for proper diverter operation).

• Terminate with the correct threaded or slip-fit connection per spout type.

Step 5: Install the Shower Riser

• Run a vertical riser from the valve’s top outlet to the shower arm location.

• Secure the riser to blocking so it won’t move.

• Install a threaded drop ear elbow for the shower arm.

Step 6: Pressure Test Before Closing the Wall

• Cap the tub spout and shower outlets.

• Turn water on and pressurize.

• Check all joints carefully for leaks.

• Fix any issues before closing the wall.

Step 7: Close and Finish the Wall

• Install backer board and waterproofing as required.

• Finish with tile or wall panels.

• Allow finishes to cure per manufacturer guidance.

Step 8: Install Trim, Spout, and Shower Head

• Install valve trim (escutcheon and handle).

• Install the tub spout with diverter:

• Threaded: use Teflon tape.

• Slip-fit: tighten set screw.

• Install shower arm and shower head with Teflon tape.

• Level and align all visible parts.

Step 9: Restore Water and Test Operation

• Turn water on slowly.

• Test temperature control and flow.

• Pull the diverter to confirm water redirects to the shower head.

• Check for leaks at trim, spout, and shower arm.

Common Mistakes to Avoid

Typical Height Guidelines (General)

• Valve handle: 900–1100 mm above tub floor

• Tub spout: ~100–150 mm above tub rim

• Shower head: ~2000–2100 mm above tub floor

Always follow the valve and trim manufacturer’s drawings over generic numbers.

Summary

To install a bathtub faucet and shower correctly:

1. Use a code-compliant tub/shower mixing valve.

2. Set accurate rough-in depth and solid support.

3. Run straight, supported plumbing for the tub spout and shower riser.

4. Pressure test before closing the wall.

5. Finish with properly sealed trim and fittings.