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Thinking about adding a bathtub where your shower is now, or even setting a tub inside your existing shower space? It can be done, and it can look fantastic. But there are important things to check first: space, structure, plumbing, waterproofing, and local building codes. This guide will walk you through the options, key decisions, steps, and simple maintenance tips to keep your new setup safe, clean, and easy to use.
Quick Answer: Can You Put a Bathtub in a Shower?
Yes, you can, but how you do it matters. There are three main approaches:
1) Replace the shower with a tub-shower combo: This is the most common and code-friendly option. You remove the shower base, install a tub, and use it for both bathing and showering.
2) Put a freestanding or drop-in tub inside a waterproof “wet room”: The entire shower area (and sometimes the whole bathroom) is waterproofed and sloped to a drain. This gives you a spa look but requires excellent waterproofing and careful planning.
3) Add a tub next to the shower inside the same glass enclosure: Works in bigger bathrooms. Both areas need proper drainage, clearances, and protection from splashing.
Each option changes plumbing, waterproofing, and cost. Before buying anything, confirm your local code rules and measure your space carefully.
Measure Your Space
Footprint and Clearances
Most alcove tubs are about 60 inches long by 30-32 inches wide (152 x 76-81 cm). Some small soaking tubs are 45-55 inches long, while deep freestanding tubs can be 55-67 inches. Make sure you have at least 30 inches of clear floor space in front of the tub for safe entry and exit. If the tub sits inside a shower, allow enough standing room for the shower zone without bumping into the tub.
Check the location of your drain. Moving a drain across the room adds cost and may require cutting the floor. If you are replacing a shower with a tub, you may need to adapt from a 2-inch shower drain to a 1.5-inch tub drain, which can affect code compliance. Plan for the tub’s overflow height and spout location too.
Doorways and Pathways
Measure all doors and hallways from your front door to the bathroom. Many tubs will not bend or twist through tight corners. Some lightweight acrylic tubs can be tilted; heavy cast iron tubs cannot. If your bathroom door is narrow, you may need to remove trim or choose a smaller tub.
Ceiling Height and Windows
A shower over a tub needs enough height to stand comfortably under the showerhead. A standard 80-inch minimum is common, more is better. If there is a window in the shower area, it should be tempered or safety glass and well sealed. Avoid wood sills in splash zones; solid-surface or tile is better.
Weight and Structure
Tubs can be heavy—especially with water and a person inside. A typical acrylic tub might weigh 60-100 pounds empty; cast iron can weigh 300-500 pounds. Water weighs about 8.34 pounds per gallon. A 60-gallon fill adds roughly 500 pounds of water alone. Add the person and you can easily exceed 700-1,000 pounds on a small footprint.
Most modern floors are built for a 40 pounds per square foot live load. Concentrated loads from tubs may require reinforcement, especially in older homes, over garages, or near long spans. If you choose a heavy tub (cast iron, stone resin) or your joists are spaced 24 inches on center, speak with a contractor or structural engineer. Reinforcement can include sistering joists, adding blocking, or installing a supporting beam. Do not skip this step—it protects your home and your new bath.
Plumbing Basics You Must Know
Drains and Trap Sizes
Shower drains are usually 2 inches; tub drains are often 1.5 inches. Many codes allow a tub-shower combo to use the tub’s 1.5-inch drain because the tub acts as a reservoir. But if you are turning a shower-only space into a tub-only space, confirm with your inspector before downsizing a drain. Traps need to be correctly sized and vented to prevent slow drainage and odors. Keep trap access where possible for future service.
Water Supply and Valves
Use a pressure-balancing or thermostatic mixing valve to prevent scalding when someone flushes a toilet or runs a sink. Many areas require anti-scald protection. Set your water heater to 120°F (49°C) to reduce burn risk. For tub fillers, check the flow rate to ensure a reasonable fill time; a deep soak tub may need a high-flow filler and larger supply lines.
Venting and Overflow
Tub drains need proper venting to avoid gurgling and slow flow. You will also need an overflow that connects to the tub drain. This small detail protects you from accidental flooding when filling the tub. Make sure all connections are sealed and test them before closing walls.
If You Keep the Existing Shower Drain
If you place a freestanding tub inside a wet room that already has a shower drain, you still need the tub to drain through its own trap and tie into the drain line correctly. Do not run a flexible hose across the floor to the shower drain. Hidden flexible connections are not code compliant and can leak, smell, or clog.
Waterproofing and Floor Slope
Waterproofing is the heart of this project. For any surface that can get wet—floors, walls, and especially changes of plane—use a full waterproofing system, not just tile and grout. Cement board is preferred for wet areas; do not use standard drywall behind tile in a shower. Apply a sheet membrane or a liquid-applied membrane according to the manufacturer’s instructions and seal all seams and corners.
Shower floors need a slope of about 1/4 inch per foot toward the drain. If your tub is inside the shower area, confirm the floor still slopes correctly so water cannot pool around the tub’s feet or base. Set the tub on a level, solid surface. For alcove tubs with a flange, bring tile or wall panels down over the flange, leaving a small gap above the tub ledge and filling it with 100% silicone. This detail helps prevent capillary wicking and leaks behind the wall.
For curbless or wet room designs, the waterproofing must be continuous across the floor and up the walls. Pay extra attention where glass meets tile and where the tub meets the wall or floor. Use flexible sealant at all changes of plane. If a steam shower is involved, you need a vapor-proof membrane rated for steam.
Code, Permits, and Safety
Most tub or shower remodels need a permit because they involve plumbing and sometimes structure or electrical. This protects you during resale and ensures safe work. Ask about drain sizes, anti-scald rules, glass safety, and any special venting for your home.
If you plan on a jetted or air tub, you will need an electrical circuit and GFCI protection, plus an access panel for the motor. Lighting inside the shower area should be wet-rated. Any glass near a tub or inside a shower must be tempered. Consider grab bars anchored to blocking in the walls. Use slip-resistant flooring and a bath mat with a grippy underside. Keep control valves within easy reach so you can turn on water without stepping into cold spray.
Choosing the Right Tub for a Shower Space
Alcove Tubs
These are designed for three-wall installations and are perfect for replacing a shower in a similar footprint. They have an integral flange to manage water. Choose a model rated for shower use with a non-slip bottom. Pair with a tub-shower valve and either a curtain or a properly sealed glass door.
Freestanding Tubs in a Wet Room
Beautiful and spa-like, but requires excellent floor slope, full-room waterproofing, and careful planning for the tub filler location. Floor-mounted fillers look sleek but need solid blocking and exact rough-in. Wall-mounted fillers can be simpler to service. Avoid placing the tub where splashes will constantly hit unprotected finishes.
Drop-In and Decked Tubs
These sit in a framed deck. They are comfortable but not ideal inside a shower zone unless the whole deck is fully waterproofed and properly flashed. Deck edges, seams, and transitions must be carefully sealed, and you will need access to plumbing connections.
Walk-In and Soaking Tubs
Walk-in tubs focus on accessibility, but filling and draining can take time. Deep Japanese-style soaking tubs fit small spaces and give a full-immersion soak in a short footprint. Both options still require correct drainage and ventilation and may need floor reinforcement.
Materials: What to Expect
Acrylic: Warm to the touch, lightweight, easy to install, but can scratch. Clean with non-abrasive, pH-neutral cleaners.
Fiberglass: Affordable and light, can dull over time, repairs are possible. Gentle cleaners only.
Cast Iron: Very durable and holds heat well, but heavy. Often needs floor reinforcement. Clean with non-abrasive cleaners; avoid impacts.
Steel with Porcelain Enamel: Durable surface, cooler to the touch than acrylic, mid-weight. Avoid heavy impacts and use gentle cleaners.
Stone Resin or Solid Surface: Luxurious look and feel, retains heat, heavy. Requires careful installation and sealing where needed.
Layout Ideas That Work
Classic Tub-Shower Combo
Install an alcove tub where the shower was and tile the walls. Use a straight or curved curtain rod or a sliding glass door. Place the showerhead high enough for comfortable use, and keep storage niches above splash lines. This is the most budget-friendly option and fits many family bathrooms.
Wet Room: Tub and Shower Together
Waterproof the entire room or a large zone, slope the floor to a linear drain, and place a freestanding tub with a wall- or floor-mounted filler. Add a fixed glass panel to control overspray. This design shines in small spaces because it removes the need for a curb and allows flexible movement around the tub.
Small Bathroom Soaker
Use a compact soaking tub with a wall-mounted hand shower. Keep shelves recessed to save space and reduce clutter. Consider a half-glass fixed panel rather than a full door to keep water in while maintaining an open feel.
Step-by-Step Planning and Installation Overview
1) Define your goal: tub-shower combo or wet room. Decide who will use it and how often. Consider kids, guests, mobility, and cleaning style.
2) Measure: length, width, height, and doorways. Map out drain locations and clearances.
3) Check structure: identify joist direction, spacing, and span. If in doubt, consult a pro.
4) Plan plumbing: drain size, trap and vent, overflow, valve type, and filler location. Create a simple sketch.
5) Get permits and select products: tub, valve, filler, waterproofing system, tile or wall panels, glass, and fan.
6) Demo and rough-in: remove old finishes, adjust framing, add blocking for grab bars and glass, run plumbing, and perform pressure tests.
7) Waterproof: install backer board, seal seams, and apply membrane. Perform a flood test if required.
8) Set the tub: level it, secure per instructions, connect drain and overflow, and test for leaks.
9) Finish walls and floors: tile or panels, grout, and seal where needed. Use 100% silicone at the tub-to-wall and vertical corners.
10) Install fixtures and glass: mount the valve trim, spout, showerhead, and filler. Set glass with proper seals and allow cure time.
11) Final checks: run water, check drainage and splashing, confirm ventilation, and review safety features.
Budget, Timeline, and Who Should Do What
Costs vary by region and scope. As a rough guide, an alcove tub-shower conversion might run $1,500 to $6,000 if you keep layout and finishes simple. A wet room with a freestanding tub can range from $5,000 to well over $15,000, depending on tile, glass, and plumbing moves.
Typical cost factors include tub ($300-$3,000+), valve and filler ($150-$1,000+), waterproofing and tile ($10-$25+ per square foot installed), plumbing labor ($100-$200+ per hour), glass ($600-$2,500), and structural work if needed. A structural consult may cost a few hundred dollars and is worth it for peace of mind.
Timeline is often 1-3 weeks for a simple swap, 3-6+ weeks for a wet room. DIYers can handle planning, demolition, painting, and some finish work. Leave plumbing, waterproofing, and glass to experienced pros unless you are confident and follow a tested system. Cutting corners on waterproofing or drains can lead to expensive damage.
Storage, Organization, and Cleaning Tips
Smart Storage That Stays Dry
Build recessed niches for shampoo and soap at a height that avoids direct spray but within easy reach from the tub. Add a small niche near the tub filler for bath salts or a book. Use corrosion-resistant shelves or caddies. Keep only daily items in the shower area; store extras in a cabinet or basket outside to prevent clutter and mildew.
Daily Care Habits
After each shower, squeegee the walls and glass and wipe the tub ledge with a microfiber cloth. Leave the curtain or door open to ventilate. Run the exhaust fan during use and for 20 minutes after.
Safe Cleaners by Material
Acrylic and fiberglass: use a mild, pH-neutral cleaner and a soft sponge. Avoid abrasive powders and harsh pads that scratch. Cast iron and steel: non-abrasive bathroom cleaners work well; rinse thoroughly. Stone resin: check the manufacturer’s guide; usually mild soap and water are best. If you have natural stone tile, avoid vinegar and acidic cleaners; use stone-safe products.
Mold, Caulk, and Grout
Inspect caulk lines every few months. If you see cracking or gaps where the tub meets the wall, remove the old bead, clean with alcohol, let dry, and reapply 100% silicone. For grout, clean gently and re-seal as recommended. Keep a small fan or dehumidifier handy in humid seasons.
Common Mistakes to Avoid
Skipping permits and inspections, which can lead to code issues or insurance problems later. Reducing a 2-inch shower drain to 1.5 inches without checking code. Ignoring floor structure when choosing a heavy tub. Using standard drywall behind tile in wet zones. Forgetting an access panel for jetted tubs or key plumbing. Installing glass without proper sealing and slope control, leading to leaks and puddles. Setting control valves too far from reach. Using harsh cleaners on acrylic or stone surfaces.
Conclusion
Yes, you can put a bathtub in your shower space—and you have more than one way to do it. The best results come from careful measuring, smart product choices, solid waterproofing, and respect for code and structure. If you want the simplest path, replace the shower base with an alcove tub and finish with tile or panels. If you want a spa look, consider a wet room—but plan the slope, waterproofing, and plumbing in detail. Whichever route you choose, build in safe access, good ventilation, and easy-to-clean surfaces. With the right planning and a bit of expert help where needed, your new bath can be both beautiful and durable for years to come.