Converting a bathtub into a walk-in shower is a popular home renovation project that can provide a more accessible and low-maintenance bathing option. However, undertaking this project requires careful planning and execution to ensure proper waterproofing and drainage. Failure to adequately waterproof and slope the shower can lead to leaks, water damage, and mold growth.

In this detailed guide, we will walk through all the necessary steps for a successful tub-to-shower conversion, with a focus on critical waterproofing and drainage considerations. Proper planning and installation of waterproof membranes, drainage systems, and moisture barriers are essential to create a durable, functional shower that will last for years to come.

Overview of the Tub-to-Shower Conversion Process

Converting a tub into a shower involves removing the existing tub, installing new drainpipes and plumbing, constructing shower pan and walls, applying waterproofing materials, tiling, and installing shower fixtures.

The key steps include:

  • Removal of existing tub: The old tub must be safely removed. This involves disconnecting and capping plumbing lines.
  • Plumbing modifications: New drainpipes and valves are installed at this stage. Access points are created for the future shower valve.
  • Building shower pan: A mortar bed is installed and sloped towards the drain. A waterproof liner is added.
  • Installing shower walls: Framing is installed and reinforced. Cement board is mounted on walls.
  • Waterproofing: Waterproofing membranes are applied to all shower surfaces. RedGard, Kerdi systems, and liquid sealants are common options.
  • Tiling: Tile is installed over shower walls and floor using a waterproof grout.
  • Installing fixtures: The showerhead, valves, and door/curtain are finally installed.

Proper waterproofing and drainage: These critical steps are vital throughout the process and will be covered in detail in this article.

Thorough planning is required to execute a tub-to-shower conversion smoothly. Now let’s focus on the key waterproofing and drainage considerations.

Critical Waterproofing Steps for Tub-to-Shower Conversions

Waterproofing is crucial to prevent leaks, moisture damage, and mold growth. Water should be fully contained within the shower area. Here are the vital waterproofing steps:

Install a Reliable Shower Pan System

The shower pan provides a watertight base and slopes to the drain. Two main options exist:

  • Mortar bed pan: This is a sloped mortar layer covered by a waterproof liner. It’s the more labor-intensive option.
  • Pre-sloped shower pans: These lightweight foam pans come with a built-in slope and liner. They simplify installation. Options include Schluter, Laticrete, and Wedi systems.

Either option must have proper slope towards the drain and a waterproof lining such as PVC. Ensure the pan liner extends 6 inches up all surrounding walls. The pan installation should be tested for leaks and corrected before moving forward.

Waterproof Shower Walls

Shower walls must be waterproofed to prevent moisture infiltration. Install cement board and use waterproofing membranes:

  • Cement board: Install over framing for a durable, mold-resistant backing for tiles.
  • Membranes: RedGard, Kerdi, and Laticrete Hydroban are reliable waterproofing membranes that can be applied over cement board. Follow manufacturer instructions carefully.
  • Liquid sealants: Seal all seams, corners, and board joints with waterproof sealant.
  • Drain flange seal: Seal the drain flange perimeter with plumber’s putty or silicone.
  • Moisture barriers: Install barriers behind walls. RedGard or tar paper help catch hidden leaks.

Waterproof Plumbing Fixtures

Use silicone sealant around all plumbing fixtures and fittings. Check valve seals for gaps and leaks. Ensure the shower arm piping is secured and leaks are sealed with silicone or thread tape.

Install Waterproof Surround Materials

Choose waterproof shower surround materials. Tile installed with waterproof grout is a popular option. Cultured marble, solid surface materials, and glass block also work well. Avoid drywall or other moisture-absorbent materials.

By properly installing waterproof pans, barriers, membranes, and materials, you can fully contain water and prevent leaks. Drainage is also key and our next section covers that.

Proper Drainage Systems for Tub-to-Shower Conversions

Inadequate drainage leads to pooling water, leaks, and mold growth. Follow these guidelines for good drainage:

Install an Adequately Sized Drain

Choose a main drain size of 2 inches or more. Smaller drains easily clog. Consider a 4-inch drain if space allows. Make sure the drain pipe itself is 3-4 inches wide.

Maintain Proper Slope to Drain

The shower pan or mortar bed must slope 1⁄4 inch per foot towards the drain. This prevents water pooling. Use a level to check slopes during pan installation.

Include a Secondary Drainage System

Include a “free-flow” secondary drain pipe under the shower floor. This catches leaks the main drain misses. The pipe should slope to an access point outside the shower.

Choose Permeable Materials

Use tile and grout that allow some water permeability. Fully impermeable materials trap moisture under tiles. Epoxy grout is not ideal for wet areas.

Inspect and Seal All Drains

Check drain seals and make sure weep holes around the drain are open. Use plumber’s putty or silicone to seal any gaps around drains.

Install Access Doors

Consider installing small access doors to drains or other plumbing elements. This allows easier access for future repairs or drain cleaning.

By following these drainage tips, you can ensure shower water flows to the main drain and excess moisture has a way to escape through secondary drainage.

Step-by-Step Installation Guide for Tub-to-Shower Conversions

Now let’s outline the complete tub-to-shower conversion process step-by-step, while pointing out key waterproofing and drainage factors:

1. Turn Off Water Supply and Remove Existing Tub

The first step is to turn off the water supply to the tub and disconnect the drain. Remove the tub carefully to avoid damaging surrounding walls and surfaces. Cap off any supply lines.

2. Inspect and Repair Subfloor

Inspect the subfloor for levelness and damage. Make any repairs needed to provide a stable base for the shower pan.

3. Install New Drain Assembly

Install a 2-inch or larger drain assembly. Ensure the drain pipe below has a diameter of 3-4 inches minimum. The new drain position may be adjusted as needed.

4. Build Out Stud Frame

Build a stud frame to desired dimensions for the new shower walls. Install cement board over studs, seal seams, and fasten securely.

5. Construct Shower Pan

Choose mortar or pre-sloped foam base. Install pan liner extending 6 inches up walls. Slope 1⁄4 inch per foot to drain. Test for leaks and repair as needed.

6. Install Plumbing and Valves

Install new shower valve and piping. Ensure seals are watertight. Create wall access to valves for servicing.

7. Waterproof Shower Walls

Apply waterproofing membranes to all wall surfaces per manufacturer instructions. Seal corners, joints, and fixtures.

8. Install Secondary Drain System

Place “free-flow” drainage pipe with slope under shower floor. Drain should terminate outside shower area.

9. Lay Shower Floor Tiles

Apply thinset mortar and lay tile floor. Use appropriate grout spacing for drainage. Allow to fully cure.

10. Tile Shower Walls and Niches

Tile walls using waterproof grout. Create recessed niches as desired. Take care to keep wall joints aligned and grouted.

11. Seal All Fixtures and Drains

Apply silicone sealant around all plumbing fixtures, valves, and drain perimeters. Check for gaps or leaks.

12. Install Shower Doors and Accessories

Mount sliding doors or curtain rod securely. Attach other accessories like shelves and grab bars as desired.

By carefully following each step, you can complete a successful and durable tub-to-shower conversion that will provide enjoyment and easy access for many years. Pay close attention to all waterproofing and drainage recommendations throughout the process.

Helpful Tips and Tricks for DIY Tub-to-Shower Conversions

Converting a tub to a shower is doable as a DIY project if you have some plumbing and tiling experience. Here are some helpful tips:

  • Take your time – don’t rush through steps or take shortcuts on key items like waterproofing.
  • Consult building codes – comply with all requirements, get permits if needed.
  • Buy quality materials – invest in reliable waterproofing membranes and leak-proof components.
  • Watch online tutorials – view video walkthroughs to better understand each installation step.
  • Test for leaks – flood the pan and walls and check for leaks repeatedly before continuing.
  • Mind cleanup – use drop cloths and work cleanly to minimize damage or mess.
  • Seal everything – use plentiful sealant and caulk around fixtures, drains, and all seams.
  • Seek input – consult with experts at your local home improvement store for product recommendations.
  • Be prepared – have all tools and materials ready before starting. Tiling supplies, sealants, plumbing parts, etc.
  • Hire help if needed – some aspects like plumbing may be best left to professionals.

The more care and attention you give to each step, the greater your chances of success and enjoyment with your new shower space. Patience and persistence will pay off.

Cost to Convert Bathtub to Shower

Converting a tub to a shower requires a considerable investment, but improves accessibility and can add value to your home. Here are typical costs:

  • $1,500-$3,000 for basic tub-to-shower conversion: This includes basic waterproof shower pan, tiling, fixtures and labor.
  • $3,000-$7,000 for high-end conversion with upgrades: Upgrades like custom tile, glass doors, lighting, and accessories increase costs.
  • $3,000-$5,000 for larger, more complex showers: Larger showers require more materials, demolition, plumbing and labor.
  • $500-$2,000 for do-it-yourself conversion: DIY saves on labor but can take more time and research.

Many factors influence cost such as layout, tile choices, plumbing complexity, and more. Careful planning helps prevent unforeseen expenses. Consult with contractors to determine the right budget for your specific project. Ultimately, the increased accessibility and convenience is well worth the investment for many homeowners.

Should I Convert My Tub to a Walk-in Shower?

Deciding whether to convert your tub to a shower is a very personal choice based on your needs, budget, and home’s value. Here are some key factors to consider:

Benefits of converting tub to shower:

  • Increased accessibility, especially for seniors or those with mobility challenges
  • Easier entry and exit than high tub walls
  • More open feeling space
  • Easier maintenance than scrubbing a tub
  • Improved resale value – walk-in showers are highly desirable

Downsides of tub conversion:

  • High cost of $3,000 – $7,000+ for professional installation
  • Loss of the relaxation soaking option – showers only
  • Possible issues if waterproofing is not done properly
  • Tub access still needed for pets or small children

Overall, switching to a shower makes sense for many empty nesters and seniors looking to age in place. However, younger families may want to retain the tub option for bathing kids. Assess your needs honestly along with your budget and home goals before deciding.

Maintaining Your New Shower and Preventing Leaks

To get long-lasting function from your new shower, be sure to follow these maintenance tips:

  • Check grout and caulk: Inspect for cracks or gaps and re-grout or caulk as needed to prevent leaks.
  • Clean regularly: Use non-abrasive cleaners to keep tile and surfaces free of grime and buildup. Avoid harsh chemicals.
  • Squeeze-dry shower doors: Opening doors while wet allows water to seep down between tracks and leak.
  • Monitor drains: Clean hair and debris from drains regularly to prevent clogs and ensure good drainage.
  • Wipe down walls: Eliminate soap scum and hard water stains with a weekly wipe-down using a squeegee and cleaner.
  • Deep clean annually: Do a thorough cleaning each year using a tile/grout cleaner and disinfectant. Re-caulk or re-seal any failing spots.

By staying vigilant and attending to repairs immediately, you can enjoy decades of service from your new tub-turned-shower. Contact professionals right away if leaks do arise. With proper maintenance, you can continue to enjoy the benefits of your new accessible shower.

Frequently Asked Questions About Converting a Bathtub to a Shower

Q: Can I do this as a DIY project or do I need a contractor?

You can potentially do this as a DIY project if you have experience with plumbing and some tiling or carpentry skills. However, for inexperienced DIYers, hiring a professional contractor is highly recommended, especially for the critical steps of waterproofing installation.

Q: How disruptive is the renovation process?

Converting a tub to a shower requires demolishing the existing tub and work on plumbing lines, which results in significant disruption. Plan for the bathroom to be out of commission for 1-2 weeks minimum. Contain dust and debris as much as possible and be prepared to use an alternative bathroom.

Q: What size drain pipe do I need?

Use a 2-inch minimum drain pipe size. For larger showers, a 3 or 4-inch drain is better to handle drainage volume. The drainage pipes below floor should be 3-4 inches in diameter as well.

Q: Can I use RedGard on shower walls instead of cement board?

RedGard alone is not a suitable shower wall backing – it should be applied atop cement board for proper support. The cement board provides structural integrity while the RedGard offers the waterproof membrane.

Q: How do I create a curb-less shower conversion?

For a curbless/zero entry conversion, ensure the shower pan slopes gradually overall and install linear shower drains to handle drainage. Extra waterproofing measures are essential without a curb.

Q: Can I repurpose my existing shower valve and plumbing?

You may be able to use the existing shower valve and supply pipes, but the plumbing will need to be reconfigured for the new shower layout. Consult a plumber to determine if parts can be reused.

Q: Should I use epoxy grout?

Epoxy grout is impervious to water but can prevent absorption under the tile surface. Standard cement grout with sealer is a better choice for shower floors and walls. Use epoxy at corner joints only.


Transforming a dated and inaccessible bathtub into a fresh walk-in shower can greatly improve the convenience and enjoyment of your bathroom. With careful planning and skilled installation, especially when it comes to critical waterproofing and drainage considerations, you can avoid leaks or mold problems down the road. Focus on choosing top-quality water barriers and drainage components, and take a step-by-step approach to ensure every aspect is handled properly. With the tips provided above, you can tackle this project with confidence and end up with a beautiful and functional new shower space built to provide many years of reliable service. Reach out to waterproofing and tiling specialists if you have any concerns along the way. Investing in professional help for key parts of the process is well worth it for long-term peace of mind.