Estimated reading time: 8 minutes
Convert Shower to Bathtub
Summary
Most conversions require moving the drain and installing a new valve with a diverter; and proper waterproofing behind the tub is essential to prevent leaks and long-term damage. An alcove tub (often 60 inches wide) is a standard size; acrylic offers affordability and ease of install, while cast iron provides durability and heat retention at higher cost and complexity. DIYers can safely tackle demolition and surround work, but should leave the plumbing, tub setting/leveling, and waterproofing to licensed pros to avoid problems down the road.
Cost to Convert Shower to Bathtub
Tired of standing in a shower when all you want is a long, relaxing soak? Converting a shower stall into a bathtub is a popular project, but what does it really cost? The final price tag is more than just the tub itself; the contractor’s installation cost is often the largest single expense.
If you’re wondering where your money actually goes, a typical mid-range project is a good place to start. More often than not, labor ends up being the biggest part of the cost.
- Labor (Plumber, Tiler): 40-60%
- Bathtub: 10-20%
- Tile & Materials: 15-25%
- Fixtures & Finishes: 10-15%
Your tub material and tile choices can quickly inflate your budget. For example: an elegant but heavy cast iron tub costs significantly more in both material and labor than a standard, lightweight acrylic one. Similarly, complex tile patterns require more time and skill, driving up installation costs. These are small things that can drive up the budget very fast, so keep them in mind when planning your shower to bathtub conversion.
Finally, always budget for the dreaded unexpected. The most common problem we see when we remove a wet area, is a rotted subfloor due to old or active leaks, that slowly seep into the subfloor and cause a soft spot that can make your tub fall straight through to the level below. This is a non-negotiable repair that can easily add $500 to $1,500 to your total cost.
Choosing Your Perfect Tub: Materials and Styles
If you’re replacing a walk-in shower with a soaking tub, you’ll most likely need an “alcove” tub—the standard type designed to fit between three walls. Before you fall in love with a particular style, measure the width of your shower space. Most tubs are a standard 60 inches (stud-to stud) and 30″ deep, but there are other dimensions (wider and/or narrower) available which may be a better fit for your space.
The next thing to think about is the material of your tub. Acrylic tubs are very popular because not only are they more durable than fiberglass, but they’re affordable, lightweight, and warm to the touch.
For ultimate longevity, many consider cast iron the best material for durability. These tubs hold heat wonderfully and come in an assortment of colors and styles; but are extremely heavy and are more expensive to install and to purchase. Keep in mind doorways and access to the bathroom, the heavier the bathtub, the harder it will be to get into the house and install.
The 4 Key Phases of Bathtub Conversion
A professional conversion follows a specific order to ensure a durable, leak-free result. The process involves four key phases:
- Demolition & Removal: The old shower, walls, and any damaged flooring are carefully torn out.
- Plumbing & Framing (The “Rough-In”): All critical behind-the-scenes work happens.
- Tub Installation & Waterproofing: Your new tub is set, and a waterproof barrier is built around it.
- Tile & Finishing Touches: The visible, beautiful surfaces are installed.
The “rough-in” phase is the most critical to the conversion. This is when a plumber moves the drain to line up with the new tub and lowers the water controls for the tub spout. Getting this hidden work done correctly is the foundation for everything that follows- one bad connection and you could have a devastating leak and water damage in the future!
The #1 Hurdle: What to Know About Bathtub Plumbing
Can you put a bathtub where a shower was without major plumbing changes? Almost never. The first surprise for many is the drain location. A shower drain is typically centered or off to one of the sides L/R, but a bathtub’s drain is at one end ONLY. A plumber must open the floor to perform a shower drain to tub drain conversion, moving the entire assembly to line up with your new tub.
Besides the floor, the water controls on the wall also need an overhaul. A tub requires a new valve, a lower trim (handle) and a tub spout in addition to the shower head. For this reason, you cannot use the old wall plumbing from a shower for a bathtub.
This new tub valve includes a crucial component called a diverter. That’s the little pull-up knob on the tub spout or a separate lever on the wall plate that switches the water flow from the tub faucet up to the showerhead. Because this work involves cutting and re-sealing pipes hidden behind walls and under floors, it is a job for a licensed plumber, not a DIYer. An incorrect connection is a guaranteed leak, leading to mold, rot, and catastrophic damage to your house.
Important Step: Waterproofing Behind the Tub
Tile and grout are not waterproof; they are water-resistant, meaning moisture will eventually seep through the porous grout (yes people, the grout is porous and you need to seal it every 6 months). That’s why the most critical part of a tub installation, that has a tile surround, must happen before a single tile is laid on the wall: waterproofing! Proper waterproofing with a Schluter membrane is the step that prevents expensive repairs and water damage down the road, and this is also the reason why you cannot simply replace a bathtub and leave the tile surround. The waterproofing membrane needs to sit on top of the tub flange, so if you remove the tub and leave the tile, you now have a gap with the potential for water penetration.
Think of it as putting a rain jacket on your house before putting on the decorative “clothing” of tile. After the tub is in place, contractors install special M2 drywall (greenboard) over the studs. Then, a waterproof membrane is applied over everything to create a seamless, sealed tub surround. This hidden barrier is what truly stops water from reaching the wood framing of your home.
Getting this step right is a MUST. A tiny gap or improper seal can allow water to cause rot and mold inside your walls. Failed waterproofing is the number one cause of catastrophic bathroom water damage and black mold.
DIY vs. Pro: What Parts of a Shower to Bathtub Conversion Can You Safely Tackle?
While many handy guys and gals have the urge to save on labor costs, a shower-to-tub conversion has steps where a small mistake can lead to catastrophic failure, and for this reason we don’t recommend it unless you’re a licensed professional.
So where can a handy homeowner pitch in? The best DIY opportunities happen at the beginning and end of the project—the jobs that are messy but have low leak risk.
- Best Left to a Pro: All plumbing work (moving drains and valves), setting and leveling the tub, and all waterproofing steps.
- Potential DIY Tasks: Careful demolition of old tile, hauling away debris, priming and painting walls, and installing the final baseboard trim.
If you want a company that will handle the entire project for you. We at Calahan will do everything from start to finish.
Your 3-Step Plan to a New Bathtub
Planning your Shower to Bathtub conversion project comes down to three key decisions: your budget, your tub style, and whether to DIY or hire a pro. With a clear understanding of the work involved, you can move forward confidently.
Here are your next three steps:
- Measure: Grab a tape measure and note the exact width, depth, and height of your current shower.
- Browse: Look at tubs online to discover materials and styles that fit your measurements and vision.
- Call: Contact at least three licensed contractors to discuss the project and get quotes.
This simple plan transforms an intimidating unknown into an exciting and achievable upgrade, ready for you to add lasting comfort and value to your home.
Q&A Section
Q1: Can I convert my shower to a bathtub myself?
A: While some aspects of the conversion can be tackled as a DIY project, such as demolition and painting, it’s recommended to hire a licensed plumber for the plumbing work to ensure a leak-free result. An improper installation can lead to significant water damage and costly repairs.
Q2: What types of tubs are available for a shower-to-bathtub conversion?
A: The most common type is the alcove tub, typically 60 inches wide, which fits between three walls. You can choose from various materials, with acrylic being popular for its affordability and ease of installation, while cast iron offers durability and heat retention.
Q3: How long does the conversion process take?
A: The timeline can vary based on the complexity of the project, but a standard shower-to-tub conversion typically takes anywhere from a few days to a week. This includes plumbing, installation, and finishing touches.
Q4: What are the common issues that might arise during a shower-to-bathtub conversion?
A: Common issues include discovering a rotted subfloor after removing the old shower or needing additional plumbing adjustments for the new tub. It’s crucial to budget for potential unexpected expenses during the project.
Q5: How much should I budget for a shower-to-tub conversion?
A: Costs can vary widely based on materials and labor. On average, you should budget anywhere from $6,000 to $12,000, with labor often being the most significant cost component. Getting multiple quotes from contractors can help you plan effectively.
