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Tub-to-Shower Conversions: What Is Involved

By the JDI Construction teamReviewed by Arthur Kulchitskiy, Project Consultant, and Denise Lacquement, Designer (bathroom specialist)Updated October 20264 min read

Quick answer

A tub-to-shower conversion replaces the tub with a shower. The drain usually moves, the valve rises to shower height, Washington's code requires a nonabsorbent wall surface to at least 6 feet above the floor, and glass must be safety glazing. In Vancouver a new valve, drain or pan needs a plumbing permit. Keep at least one tub in the house if children or resale matter.

Swapping a tub nobody uses for a walk-in shower is one of the most common bathroom projects. It looks like a simple trade, but almost everything inside the wall and floor changes: the drain, the valve, the waterproofing and often the floor itself. This page explains what is involved, what Washington's codes ask for, how permits apply, and what to weigh before you remove a tub.

Why people convert

The reasons are usually practical:

Getting in and out. Stepping over a tub wall gets harder with age, injury or a baby on your hip. A low curb or curbless entry removes that step.
Nobody bathes. The tub is used as a shower with a curtain, and the household would rather have a larger shower with glass and a bench.
The tub is failing. A chipped or cracked tub, or a leaking surround, means the wall has to be opened anyway.
Space. A shower with clear glass can make a small bathroom feel bigger than a tub with a curtain.

If you are still deciding whether to keep any tub at all, tub or no tub lays out both sides.

Keep at least one tub in the house?

This is the question to settle first. Families bathing small children usually want a tub, and buyers with young children may look for one. We have no reliable figure on how much a missing tub affects resale in Clark County, so treat it as judgment rather than math. A useful rule of thumb: converting a tub in a primary bathroom when the hall bathroom keeps one is a small risk; removing the only tub in the house is a bigger one. Think about who is likely to buy the house next, not only how you use it now.

What changes in a conversion

Part	What usually changes
Drain	A tub drain sits at one end; a shower drain sits under the new floor, often centered or along one wall for a linear drain. Moving it means opening the floor.
Valve	Raised from tub height to shower height, and usually replaced. Valves certified to ASSE 1016 are pressure-balancing, thermostatic or both, with a limit stop the installer sets.
Showerhead	Washington's plumbing code caps showerheads at 1.8 gallons per minute at 80 psi; multiple heads on one valve share that cap unless only one runs at a time.
Floor	A preformed base, or a tiled floor sloped to the drain over a pan or bonded membrane.
Walls	Washington's residential code (R307.2) requires shower walls to have a nonabsorbent surface to at least 6 feet above the floor.
Entry	A curb, a low curb, or curbless.
Glass	A door, a fixed panel or a curtain. Glass must be safety glazing.
Extras	Niche, bench, grab bar blocking and a handheld shower are easiest to add while the wall is open.

Curb or curbless

A curbed shower keeps water in with a raised threshold and is the simpler build. A curbless shower lets you walk or roll straight in, but the floor inside the shower has to drop below the bathroom floor so water runs to the drain, which usually means recessing the subfloor or raising the rest of the room. Over a crawl space this is often practical; on a slab it is more work. See curbless showers for the details.

Waterproofing

Tile and grout are not waterproof. The water stays out of the wall because of what is behind them: a traditional pan liner under a mortar bed, or a bonded sheet or liquid-applied membrane over backer board. In a tub alcove, the area that gets wet grows taller and wider once it becomes a shower, so the waterproofing has to cover more than the old tub surround did. Our page on waterproofing explained covers the methods.

Glass

Washington's residential code treats glazing in walls or enclosures containing or next to a shower as a hazardous location when its bottom edge is less than 60 inches above the standing surface (R308.4.5). Shower doors and enclosures must pass the federal CPSC safety glazing standard, 16 CFR 1201, and each pane must carry a permanent manufacturer's mark that stays visible after installation.

Permits for a tub-to-shower conversion

A conversion replaces fixtures and moves pipes, so expect a permit. As of October 2026:

City of Vancouver. Vancouver Municipal Code 17.08.090 exempts only removing and reinstalling a tub or shower where the work does not involve replacing or rearranging valves, pipes or fixtures. A conversion does all three. When it is part of a larger remodel, the city includes the plumbing in the residential building permit.
Unincorporated Clark County. The county requires a plumbing permit for installing any plumbing fixture.
Other cities. Camas, Battle Ground, Ridgefield and Washougal each word their rules differently; check with the city.

Plumbing work in Washington must be done by a certified plumber, or by an owner on their own home. You can check a plumber on L&I's Verify a Contractor, Tradesperson or Business tool. Our page on whether a bathroom remodel needs a permit covers the details.

What it costs

In JDI Construction's published bathroom cost calculator, a walk-in or curbless shower is an add-on with a planning range of $4,000-$10,000 before sales tax, on top of the bathroom remodel ranges. That is a planning range, not a quote. Where the drain moves, whether the entry is curbless and what tile you choose decide where a real conversion lands.

Next steps

When you are ready to price it, shower-only remodels and tub-to-shower jobs with JDI explains what JDI includes and how to request a quote. JDI also has a current walk-in shower and tub offer; check that page for the terms. You can see the service on our Vancouver shower remodeling page, or read our earlier article on bathtub-to-shower conversion.

Common questions

Can a shower fit in the space of a standard tub?

Usually, because the shower takes over the tub's footprint and plumbing wall. What changes is the floor: the shower needs a base or a tiled floor sloped to a drain, and the drain position often moves. A curbless entry takes more floor work than a curbed one.

Will removing my only tub hurt resale?

It can narrow the pool of buyers, especially families who bathe small children. No source we rely on puts a number on it, so treat it as a judgment call: if the house has another tub, converting one is a smaller risk than removing the last one.

Do I need new glass, or can I use a curtain?

A curtain is allowed. If you choose a glass door or panel, Washington's residential code treats glazing in shower enclosures as a hazardous location, so it must be safety glazing tested to the federal CPSC standard and carry a permanent mark.

Does the old tub valve have to be replaced?

It almost always moves, because a tub valve sits low and a shower valve sits at standing height, and the wall is open anyway. Replacing it with a valve certified to ASSE 1016 gives you pressure-balancing or thermostatic temperature control.

Sources

Checked October 2026. Rules, fees and programs change; confirm the current requirement with the agency before you rely on it.