DIY Network

Installing a Whirlpool Tub

DIY experts show how to install a whirlpool tub including making the plumbing connections and woodworking. Check the plumbing and weight requirements of the proposed tub prior to purchase to avoid disappointment.

More in Bathroom

  • Time

    Two Days

  • Price Range

    $1,000 - $2,500

  • Difficulty



Step 1: Plan Strategy and Fit Pipes

Installing a whirlpool tub requires high-level electrical, plumbing and carpentry skills. Familiarize yourself with the unit and determine what portions of the project you'll do yourself or outsource to professionals.

The mechanism that controls the tub is a pump that recirculates the water.

The tub also has a diverter which controls whether the water comes from the jets or the shower. Since fixtures don't come installed, you'll have to install them yourself. Follow manufacturer's directions to determine where they go.

The installation requires a lot of copper tubing. Measure the amount of pipe needed, based on the manufacturer's instructions, and cut the pipe to length with a pipe cutter.

Dry-fit the pipes using copper fittings.

"Sweat" the copper tubing in place around the tub: use a torch to join the ends of the pipe after wiping ends with an Emery cloth and applying soldering flux to facilitate bonding.

pipe cutters used to cut copper tubing

Step 2: Install the Tub

Build a knee wall to support a deck around the perimeter of the tub. The tub itself rests on the floor, not the knee wall. Important: Heavy tubs in cast iron may require reinforcement of the floor below it. Be sure to include an access panel so that you can service the tub as needed.

As needed, notch the interior sides of the knee wall with a jigsaw to accommodate the tubing for the tub.

Screw the knee wall to the wall studs.

Build decking out of 2" x 6" boards.

Cut holes in the floor for an appropriate size to accommodate the water supply lines and drain.

A cast-iron whirlpool tub weighs about 600 pounds, so you'll need help to lift it into place. Be careful not to damage the tubing or fittings.

Install sheet-metal shims to level the tub. Raise the tub with a crowbar, using a 2"x 4" board as a fulcrum.

Step 3: Install the Pump and Plumbing

Connect the main water lines by sweating them in place.

Drop the trip-lever assembly through the appropriate hole and secure the lever with screws. You may want to have a plumber connect the drain to the trap and the main drain line.

Connect the pump to your electrical system, using standard electrical connections. The pump should be on a circuit that uses a ground fault circuit interrupter (GFCI).

Attach the high-pressure hose for the showerhead to the diverter.

Thread the other end of the hose through the hole in the side of the tub.

Hook the shower hose to the end of the high-pressure hose. Purge the lines to remove any sediment before finishing the installation of the showerhead.

Install the diverter valve by dropping the cartridge into place and tighten it securely (Image 1).

Set the brass cowling and decorative sleeve in place (Image 2) and place the combination cover/knob on top.

Step 4: Complete the Plumbing Attachments

Turn on the water and check for leaks.

Attach the front knee wall by screwing it to the wall studs on the ends. Leave room between the bottom of the tub flange and the top of the wall for tile or other filler materials.

Attach the showerhead unit tightly to the hose.

Attach the faucet. For a seawall faucet, which sends water through several outlets along a wide band of metal, insert the O-ring nozzle into the supply hole and tighten the anchor screws. Attach the cover.

Install any additional accent pieces on the fixtures.