How to Install a Pier-Type Whirlpool Tub

A whirlpool tub provides relaxation in the privacy of your home.

A common aspect of bathroom remodeling entails the installation of a whirlpool tub, and modern tub designs enable the placement of whirlpool tubs in standard-sized tub spaces. This gives many homeowners the option of upgrading their bathroom to create a more relaxing atmosphere. In a pier type Whirlpool installation, the brim of the tub rests on the ledge, lending a sophisticated, elegant appearance to any bathroom.

Things You'll Need

• Whirlpool tub
• Measuring tape
• 2-by-4-inch stud-grade lumber
• Carpenter's level
• Drill
• Drill bit
• 16d nails
• Mortar mix
• Drain assembly
• Plumber's putty
• ½-inch plywood
• Sealant
• Ground Fault Circuit Interrupter (GFCI breaker)
• Primer
• Ceramic tile

Instructions

Preparation

1. Speak to the local code inspector to learn the requirements for installing a whirlpool tub. Some codes may require a licensed electrician or plumber perform some aspects of the project. Obtain a building permit before proceeding with the installation if necessary.

2. Check the manufacturer’s instructions for determining the weight requirements for the tub; make sure the floor is in solid condition, inspect the subfloor for damage and ensure that the floor joists are structurally sound.

3. Reinforce the joists as necessary to support the tub's weight. Replace materials and make repairs as necessary before proceeding with the installation. Ensure that the floor is level by checking the surface with a carpenter’s level.

Enclosure

1. Frame the whirlpool tub with 2-by-4-inch stud-grade lumber (use 2-by-6-inch lumber if you want to construct a wider pier). Select straight boards to build the frame. Measure from the floor surface to the underside of the tub brim to determine the height of the wall. Subtract the thickness of the plywood, which covers the top plate, to obtain the final height of the wall.

2. Build a wall section for each side of the tub not attached to a bathroom wall. A wall section consists of horizontal boards -- top and bottom plates. Vertical components, called studs, are attached between the top and bottom plate to create a wall section.

3. Place the two plates on edge. Use a measuring tape to mark 16-inch "on center" lines. "On center" refers to the center of one stud to the center of the next stud. Starting from one the end of the board, mark 3/4-inch lines on each side of the 16-inch marks, which help identify the proper placement of studs between the top and bottom plates.

4. Insert the studs between the 3/4-inch marks of the top and bottom plates. Secure the studs with two 16d nails. Pre-drill the nail holes with a drill bit slightly smaller than the diameter of the nail, which prevents cracking the wood.

Tub Installation

1. Apply plumber's putty around the drain opening and attach the drain. Follow the manufacturer's instructions for installing the overflow assembly and attaching it to the drain. Make sure the overflow linkage works properly before setting the tub inside the enclosure.

2. Pour a layer of mortar along the floor surface – enough to support the tub from the bottom. Apply a bead of sealant along the surface between the brim of the tub and the ledge. Position the whirlpool tub in place before the mortar sets. Make sure the floor supports the weight of the tub along its entire bottom. Complete the installation of the tub drain to the trap. Tighten all connections.

3. Shut off the electricity for the applicable circuit at the main distribution panel before proceeding with electrical connections. Read and follow the electrical instructions and diagram for making the appropriate connections, including the installation of at least one separate dedicated circuit along with a Ground Fault Circuit Interrupter (GFCI).

4. Fill the tub with water 2 inches above the highest jets. Check to ensure the drain and pump components do not have leaks. Turn the whirlpool on and recheck for leaks as the unit operates. Install the water resistant covering, such as marble or ceramic tile over the enclosure to complete the project.

Tips & Warnings

• If you don't have the electrical experience necessary to safely or comfortably complete the work, enlist the help of someone with the necessary experience or hire a licensed electrician.

References

• Home Depot; Installation Guide for Whirlpool Tubs
• Master Faucet; : Building a Tub Frame