What shower and bathtub installation is, and why Monrovia sees it
Shower and bathtub installation covers the plumbing behind a new or rebuilt bathing space: the valve, the supply lines, the drain and trap, and the waterproofing the rest of the build depends on. Whether you are replacing a worn tub, building a new shower, or converting an old tub into a walk-in shower, the plumbing has to be done right before the tile and glass go in, because fixing it afterward means tearing that work back out.
The valve is the heart of the job. A modern pressure-balancing or thermostatic shower valve protects you from the scald when someone flushes a toilet elsewhere in the house, and it is the part that has to be set at the correct depth and height for the finished wall. We install it so it works with the trim and the wall thickness the rest of the project is planning for.
Drains and waterproofing are where shortcuts come back to haunt a bathroom. A shower pan has to be sloped and sealed so water goes down the drain and nowhere else, and a tub drain and overflow have to be plumbed and tested before they are buried. We handle the pan prep and the drain so the waterproofing the project relies on actually holds.
Monrovia's older homes shape this work in a couple of ways. Heritage baths in Old Town and Mayflower Village often have original cast iron tubs worth keeping and old drain configurations that do not match modern fixtures, so part of the job is adapting new plumbing to an old room. And because the city's water is very hard, we steer people toward valves and fixtures that hold up to scale.
Whether it is a straightforward tub swap or a full tub-to-shower conversion, the plumbing is what the finished bathroom rests on. We get the valve, drain, and waterproofing right so the tile setter and the homeowner are building on something solid.
Planning a shower or tub install
The plumbing has to be planned around the finished space, so we work through a few things first.
Match the valve to the build
We confirm the valve type, depth, and height against the planned wall and trim, so the rough-in lines up with the finish and nobody is opening a wall later to move it.
Plan the drain and pan
We set the drain location and, for a shower, the pan slope and waterproofing prep so water drains correctly and the space stays sealed. For a tub, we plumb and test the drain and overflow before anything covers them.
Adapt to an older bathroom
In heritage baths, we plan how new plumbing meets old drain configurations and original fixtures, including cast iron tubs worth preserving, so the install fits the room.
Installation methods we use
The plumbing scope depends on whether you are swapping a fixture or reworking the space.
Shower valve and supply install
We install the pressure-balancing or thermostatic valve and run the supply lines to it, set at the right depth and height for the finished wall and trim.
Tub and shower pan plumbing
We plumb tub drains and overflows and prepare shower pans with proper slope, drain, and waterproofing so the finished base does not leak behind the tile.
Tub-to-shower conversion
We reconfigure the plumbing and drain to turn an old tub alcove into a walk-in shower, a popular update in homes whose owners want a step-free, modern bathing space.
Signs it is time for a new shower or tub
A few things point toward replacing rather than patching:
- A shower valve that scalds when another fixture runs
- A tub or pan that leaks into the ceiling or wall below
- Cracked, worn, or dated fixtures past simple repair
- Wanting a step-free walk-in shower in place of a tub
- An old drain or valve that no longer matches available parts
Cost of shower and bathtub installation in Monrovia and the west SGV
Pricing covers the plumbing side of the install. Tile, glass, and finishes are separate. A valve swap is modest. A full conversion is a larger project.
Typical price ranges (2026)
| Job | Typical range | Notes |
|---|---|---|
| Shower valve replacement | $300 – $800 | Cartridge or full valve |
| Tub or shower install (plumbing) | $1,500 – $5,000 | Plumbing side of the install |
| Tub-to-shower conversion | $3,000 – $8,000 | Reconfigure plumbing and drain |
| Pan and waterproofing prep | $500 – $2,000 | Shower base done right |
Treat these as ballpark 2026 ranges for the area. What you actually pay depends on your home's age, the access, and the parts required, and we put a firm figure in writing after a no-cost look.
Other plumbing work we handle
A new shower or tub is often part of a larger bathroom project, and we handle the full bathroom remodel plumbing too, from moving fixtures to reworking supply and drain lines. If the room's supply lines are old galvanized, a remodel is the ideal moment to repipe that bathroom while the walls are open.
Frequently asked questions
Can you convert my old tub into a walk-in shower?
Yes, a tub-to-shower conversion is one of our common bathroom jobs. We reconfigure the plumbing and drain, prepare the pan and waterproofing, and set the valve so the new shower is ready for tile and glass.
Why does my shower scald me when someone flushes?
That is an old valve without pressure balancing. A modern pressure-balancing or thermostatic valve holds the temperature steady when water is drawn elsewhere, and installing one ends the scald-and-chill cycle.
Can you keep my original cast iron tub?
Often, yes. Heritage cast iron tubs are worth preserving, and we adapt new plumbing and drains to work with them, so you keep the character of the bathroom while updating what is behind the wall.
What plumbing has to be done before tiling?
The valve, supply lines, drain, and pan waterproofing all go in and get tested before tile. Doing them right first is what keeps the finished bathroom from leaking, because fixing plumbing afterward means removing the tile.
Do hard-water fixtures matter in Monrovia?
They do. The city's very hard water scales valves and fixtures over time, so we steer people toward quality valves and finishes that hold up, which means fewer repairs down the line.
Do you do the tile and glass too?
We handle the plumbing side, the valve, supply, drain, and pan prep, so your tile setter and glass installer build on a sound, sealed base. We coordinate with the rest of the project as needed.
Related plumbing help
Related services
Service areas we cover
From the blog
Our Monrovia plumbing blog goes deeper on the topics above, with local cost ranges and practical repair-or-replace guidance.
Planning a new shower or tub?
Call and we will handle the plumbing side right, valve, drain, and waterproofing, so your finished bath holds up.