How to install a walk-in tub: the prep work

Jeffrey Anderson | Improvement Center Columnist | October 6, 2016

So you're planning on installing a walk-in tub? It's a smart decision if there is anyone in your family with mobility issues such as seniors or those with health concerns. But now that you've made the decision, what's next? Well, if you're the average homeowner, the smart move is to have the business where you're purchasing the tub handle installation or to hire a contractor. Removing the old fixture and installing the new is not a job for a beginning or even a somewhat seasoned DIYer. If a connection isn't done correctly, the result can be considerable water damage to your home - especially if you happen to be away when it occurs.

However, if you feel confident in your abilities, here is a guide on how to install a walk-in tub. Part 1 will discuss the initial prep work, and actual installation will be outlined in Part 2.

How to install a walk-in tub: Getting started

walk-in tub

Walk-in tubs are available in numerous sizes. Unless you're planning a total bathroom renovation, it's best to get a model that matches the dimensions of your existing tub. Choosing a unit that's larger or smaller often requires framing changes in the room and a bigger fixture may also reduce clearances required by building code. Manufacturers know this, so many companies, such as American Standard, offer walk-in models in the same dimensions as standard tubs.

When purchasing a tub, "handing" is also important. The handing of a tub is determined by looking at the drain hole. If it's on the right as you face the fixture, then it's a right-handed tub and the reverse is also true. You'll want a walk-in unit that's handed the same as your existing tub.

Installing walk-in tubs: Tools you'll need

Every walk-in tub installation is a little different due to issues specific to that home, but in general here is a list of the tools that may be needed:

  • Framing hammer
  • Four foot level
  • Torpedo level
  • Assorted adjustable wrenches
  • A pipe wrench
  • Wood shims
  • Screwdriver - possibly both a Phillips and straight tip
  • Plumber's putty
  • Mortar mix
  • Measuring tape
  • Trowel
  • Silicone caulk
  • Construction adhesive
  • Galvanized roofing nails - one inch length is recommended
  • Utility knife
  • Crowbar

In addition, depending on the type of tub being removed, you may need some sort of power saw.

Removing the existing tub

Before doing anything to remove the existing tub, make sure the hot and cold water lines to the fixture are shut off. The valves may be in the wall behind the faucet where they can often be accessed through a panel or they could be at the water heater or where the main water supply line comes into the home. While the faucet and handle sets don't always have to be removed for walk-in tub installations, in most cases they do.

The amount of demo required depends on the construction of the existing tub and the configuration of the new walk-in model. Some standard tubs only consist of the base unit with the surround being constructed of sheetrock and ceramic tile. Others may have fiberglass panels that make up the surround portion of the tub. And lastly, there are some tub units that are all one piece with attached surrounds.

The best possible scenario to have is an existing tub with separate fiberglass surround panels. That configuration normally involves just a little sheetrock repair work to remove the tub and panels and install the new unit with its panels. However, here are the typical demo steps for all configurations:

  1. Undo the drain connection - If there is an access panel that allows you to reach the tub drain through a wall, this step may be fairly easy. However if there isn't, you may need to cut a hole large enough to work through in the ceiling below the drain or the wall directly behind the overflow. Disconnect the drain lines at the bottom of the tub and at the overflow. This can usually be done with a pipe wrench. If possible, stick a rag in the end of the drain pipe so debris doesn't fall in and clog it during the rest of the demo.
  2. Disconnect water lines - Existing tubs that have surround panels or are a one-piece with attached panels will need to have the faucet and handle sets removed to take out the panels. This can normally be accomplished from the inside of the tub with a screwdriver. Again, make sure the water supply lines are off before starting this step.
  3. Remove the panels - If the existing tub has separate panels, they should be removed at this point. The tops of the panels normally have a lip that extends behind the sheetrock. This lip is secured with nails to hold the surround in place. Cut the sheetrock about a foot above the top of the surround panels all the way around and remove the sheetrock. Using the crowbar and hammer, remove the nails holding the surround panels in place. Once the nails are gone, the panels should be able to be lifted up and out.
  4. One piece units and those without a surround - A one piece tub that has attached surround panels should have the sheetrock cut about a foot above the surround and the nails removed just as in the above step. A tub without panels should have the sheetrock cut about a foot above the tub and the nails securing the tub removed. This may involve having to take out some ceramic tile - if so, make your cut at a horizontal grout line being careful not to damage the tile above the cut. It's just about impossible to reuse the tile being removed so you don't have to be too careful with those.
  5. Remove the tub - Once the surround panels have been removed and the nails securing the tub are out, the unit itself can be carefully lifted up and out of the space. It should then be taken from the room. Depending on the type of flooring you have, it's possible that where the floor meets the tub base may need to be loosened or removed before the tub can be lifted up. The one exception is a one piece unit with attached surround panels - the only way it's coming out and through the doorway is in pieces. Use a saw such as a reciprocating model to very carefully cut the panels from the tub until the pieces are small enough to fit through the doorway. Be very cautious if you have to perform this task as fiberglass shards are very sharp. Wear ear and eye protection while doing it and heavy gloves are also recommended.

Once the tub and surround have been removed from the room, sweep and use a shop vacuum to thoroughly clean the room. You are now ready for the walk-in installation.

About the Author

Jeffrey Anderson has a Degree in English from V.M.I., and served as an officer in the Marine Corps. He worked in Residential and Commercial construction management for 25 years before retiring to write full time. He spends his time writing, remodeling his old farmhouse, and in animal rescue.