The tub itself comes out in about an hour. Sometimes less, if the crew is willing to cut it into pieces first. What takes the rest of the job is everything the tub was hiding: a drain in the wrong place and the wrong size, a valve that has to be swapped, and a floor that now has to be waterproofed like a shower instead of a tub surround.
How many days that takes depends on what’s under the tub. But it’s days, not a day. And the number on your quote can move once the wall is open.
A tub is a finished, waterproof object you set in place. A tile shower is something you build on site, layer by layer. That swap is why a tub to shower conversion touches the plumbing, the floor, and the wall framing, not just the fixture you picked out.
What Changes Behind the Wall When the Tub Comes Out
Four things change: the drain, the framing, the valve, and the waterproofing. Each one has its own cost and its own way of surprising people.
The drain moves, and it gets bigger
A standard alcove tub is about 60 inches long and drains at one end through a 1½-inch line. A shower drains through a 2-inch line, usually closer to the middle of the base. So the drain doesn’t just shift a few feet. It gets replaced with larger pipe, and that means opening the floor.
How hard that is comes down to what’s under you. Over a crawlspace, a plumber can often work from below and the finished floor barely gets touched. Over a slab, the concrete has to be cut, the new line run, and the slab patched before anything else happens. Homes around Pleasant View and Nashville come both ways. That single difference can decide whether the plumbing is a morning or two days.
The valve almost always gets replaced
A tub-and-shower valve has a diverter and feeds a tub spout below it. A shower-only valve needs neither. Even when the old valve still works, it sits in a wall that’s already open, and leaving it means leaving a capped hole where the spout used to be. Most conversions replace it with a pressure-balancing valve while the access is free.
Waterproofing turns into something you build
The tub was the waterproofing. Pull it, and the base, the curb, the corners, and the wall behind the tile all have to be sealed as one system. Sheet or liquid membrane, a sloped mortar bed or a pre-formed base, every seam treated. This is the step that decides whether the shower stays dry or quietly leaks into the joists.
Before Anyone Swings a Hammer
The measuring comes first. A designer maps the existing alcove, locates the drain and the vent, checks what’s under the floor, and confirms the new base fits the opening the tub leaves behind. That visit is also where the number comes from. Nobody who hasn’t seen the bathroom can price the drain.
Selections happen here too, and they drive the plumbing more than people expect. One showerhead is a different supply and drain plan than a rain head plus a handheld. Showerheads carrying the EPA’s WaterSense label must demonstrate that they use no more than 2.0 gpm, so two of them running together is the math your plumber is doing while you’re picking finishes.
One question is worth settling before any of that. Is this the only tub in the house? A walk-in shower remodel that takes out your last bathtub changes who wants to buy the place later, and it’s a cheaper decision to make now than after demo.
Demo Day and the Things That Change the Scope
Demo is loud and fast. Tile comes off, the tub gets cut out, and by lunch you’re looking at studs and subfloor. That’s the moment the job either holds its plan or doesn’t.
Rot shows up first. Water gets past old tub surrounds at the corners, and the damage collects in the bottom plate and the subfloor near the drain. Framing is the second one. Older alcoves were sometimes built tight around one specific tub, so squaring things up for a modern base takes time nobody budgeted.
Third is whatever is living inside the wall you wanted to move: a vent stack, a heat run, wiring that has to be rerouted before the plumber can do anything.
None of that is unusual. It’s why a careful contractor quotes a range instead of a single number, and why the calls you make in that first week are hard to reverse once the walls close up.
Putting the Shower Back Together
Rebuild runs in a fixed order. Plumbing rough-in, and an inspection where the local jurisdiction requires one. Then the base, then waterproofing, then tile, then glass and trim. Glass is measured after tile is set, which is why the door arrives well after the shower already looks finished.
Sequence matters more in a bathroom than almost anywhere else in the house. Getting the trades scheduled in the wrong order is how homeowners end up paying for the same square foot twice.
Add one thing while the ceiling is open: a real exhaust fan, vented outside. A walk-in shower with a wide opening throws far more steam into the room than a tub with a curtain ever did. EPA guidance on moisture and mold is to keep indoor humidity below 60 percent (ideally between 30 and 50 percent) relative humidity. An undersized fan quietly undoes good waterproofing.
What You Handle and What the Crew Handles
Most of the friction in a conversion comes from this line being fuzzy. Here’s where it usually sits.
Your side
- Clear the bathroom and the hallway the crew will carry material through.
- Lock in tile, base, glass, and fixtures before demo. Late changes cost days, not hours.
- Pick a backup bathroom and expect noise during working hours.
- Keep pets out of the work zone.
Their side
- Floor protection and dust containment on the route in and out.
- Demo, haul-off, and disposal of the old tub and tile.
- Plumbing, framing, waterproofing, tile, and glass.
- Permits and inspections where the local jurisdiction requires them.
That split holds up better when the design work and the bathroom remodeling run through the same team. The person who measured the alcove stays connected to the crew that opens it, and the base that got specified is the base that shows up on the truck.
Which side of the line your project sits on gets clear once somebody has actually stood in the room. Have the alcove measured and the floor checked before you commit to a budget.
How Long It Takes and What Sets Your Number
No one can give you a real figure over the phone, and the honest reason is the drain. Two bathrooms that look identical from the doorway can price thousands apart depending on whether the plumber works from a crawlspace or cuts a slab.
What stretches the schedule:
- Slab construction instead of crawlspace access under the bathroom.
- Moving the shower outside the tub’s original footprint.
- Custom glass, which can’t be measured until tile is set.
- Rot or framing repair discovered at demo.
- Small mosaic tile, which takes far longer to set than large-format tile.
What holds it down: keeping the drain near where it already is, choosing a pre-formed base over a mortar bed, and staying inside the existing walls. Those same forces run through the whole room, which is why the line items that move a bath budget are worth reading before you set one.
Frequently Asked Questions
How long does it take to remodel a shower?
Most of the calendar is curing and glass, not labor. Demo and rough-in move quickly. Waterproofing has to cure, tile has to set, grout has to cure, and custom glass only gets measured once the tile is finished. A conversion that stays inside the existing walls with an easy drain runs shorter than one that moves the drain through a slab. Ask for a range and ask what would push it to the long end.
Can I use the bathroom while the shower is being built?
Not that one. Water gets shut off to the room during rough-in, and the space stays sealed for dust control through demo and tile. Plan on another bathroom for the full run of the project. If your house only has one, say so before anything gets scheduled, because it changes how the work has to be staged.
Does a tub to shower conversion always mean opening the floor?
Almost always, at least in part. A tub drains through a smaller line at one end of the alcove, and a shower needs a larger line nearer the middle of its base. Even a conversion that keeps the exact same footprint usually needs that drain relocated and upsized, which means getting under the floor. The exception is a layout where the existing drain already sits where the new base wants it.
What happens if the crew finds rot behind the tub?
Work stops, you get shown the damage, and that piece gets priced before anyone continues. Rot near an old tub drain is common enough that it belongs in the conversation up front rather than as a mid-project surprise. Ask during the estimate how discoveries at demo are handled and whether the contract carries an allowance for them.
A contractor who answers that clearly is telling you something useful about the rest of the job.
Ready to Find Out What’s Under Your Tub?
A conversion is mostly a plumbing and waterproofing project wearing a tile finish. The design half is the part you’ll enjoy. The half that sets your budget is under the floor, and looking is the only way to know.
Guthrie Kitchen & Bath Plus handles kitchen and bathroom remodeling across Pleasant View, Nashville, and the surrounding Middle Tennessee area. Book a design consultation and get the alcove measured, the drain located, and a scope built on what’s really behind your wall.