How to Replace a Bathtub With a Shower


Replacing an old bathtub with a new walk-in shower is a popular home renovation project that can completely transform your bathroom. Installing a shower instead of a tub opens up floor space, makes entering and exiting easier, and creates a more modern, spa-like feel. The process does involve some plumbing work, demolition of the old tub, waterproofing, and installing shower pan and enclosure. But with proper planning and the right techniques, a DIYer can tackle a tub-to-shower conversion and save on labor costs. This article will provide a step-by-step guide to replacing a bathtub with a shower.

Things to Consider Before Starting

Before you begin ripping out the old tub and tile surround, here are some important factors to consider:


  • A tub-to-shower conversion can range from $2,000 to $6,000 professionally installed. Doing it yourself can shave off labor costs.
  • The shower enclosure and plumbing parts will be a major expense. Prefabricated shower stalls are available in different sizes, materials like fiberglass, acrylic, cultured marble and costs. Custom tile showers are pricier.
  • Don’t skimp on waterproofing materials – this is crucial for preventing leaks and moisture damage. Quality materials upfront will pay off.

Space and Design

  • Measure carefully to ensure there’s adequate space for a shower stall. Standard sizes are 36″ x 36″ or 48″ x 48″ up to 60″ x 42″.
  • Decide on an enclosure style – curved rod, frameless glass, or neo-angle. Glass gives a more open feel.
  • Determine the shower layout – decide on showerhead wall placement and if you want multiple showerheads.
  • Select shower floor materials – ceramic tile, vinyl, acrylic materials. Tile gives a high-end look.
  • Choose finish materials that match your bathroom’s decor – colors, patterns, texture etc.

Plumbing Considerations

  • For drainage, make sure there’s an existing shower drain and it’s positioned properly. This can affect layout.
  • The hot and cold supply lines must be accessible – if not, alterations to supply plumbing may be needed.
  • Adjustments to supply and drain lines may require cutting into walls or floors, which can add complexity.

Demolition and Construction Work

  • Removing the old tub can damage walls, plumbing, electrical. Be prepared for repairs.
  • Accessing and moving drain lines requires cutting into drywall and floors.
  • Waterproofing is vital and improper methods can lead to leaks, mold growth.

Doing the required plumbing prep work and understanding all that’s involved will lead to a smooth installation. Consulting a pro for advice before starting is recommended.

Tools and Materials Needed

These tools and materials will be needed to demolish and remove the old tub and complete the new shower installation:

Safety Gear

  • Safety glasses
  • Dust mask
  • Ear protection
  • Gloves

Demolition Tools

  • Sledgehammer
  • Cold chisels
  • Flat pry bar
  • Reciprocating saw
  • Utility knife
  • Wheelbarrow

Building Materials

  • Cement backerboard
  • Thinset mortar
  • Tile or enclosure unit
  • Tile grout/caulk
  • Fiberglass insulation
  • PVC drain pipes
  • PEX supply lines
  • Solder and flux
  • Wood blocking

Plumbing Parts

  • Shower pan or liner
  • Shower drain
  • Mixing valve and trim
  • Showerhead
  • Flanges and elbows

Waterproofing Materials

  • Liquid waterproofing membrane
  • Waterproofing tape
  • Drain flashing
  • Thinset mortar
  • Cement backerboard

Finishing Materials

  • Tile, accent tiles
  • Tile edging


  • Tape measure
  • Level
  • Screwdriver
  • Drill and bits
  • Wrench
  • Hack saw
  • Trowel
  • Grout float
  • Caulk gun
  • Mixing paddle

Step-by-Step Installation Guide

Follow these key steps to safely replace a bathtub with a new shower. Be sure to consult local building codes for any requirements and get all necessary permits.

1. Turn Off Water Supply Lines

The first step is to locate the shut-off valves for the tub’s hot and cold water supply lines. They are usually under the tub or nearby. Turn the handles clockwise to shut off the water.

Turning off the main water supply to the house is also an option. Once the water is off, turn on the tub faucet to drain any remaining water in the pipes.

2. Remove Fixtures and Access Panel

Remove the tub spout and showerhead by unscrewing them from the walls. Detach any nearby escutcheons. Check walls around the tub for an access panel – this must be taken out to get at plumbing. Cut surrounding caulk to free the panel.

3. Prepare the Work Area

Clear out everything around the tub and lay down drop cloths. Remove shower doors, curtain rods, medicine cabinets etc. Wear safety glasses, gloves and a dust mask. Tape plastic sheeting over doorways to prevent dust spreading.

4. Cut Out Drywall Around Tub

Measure and mark a cut line about 6 inches up from the tub rim. Use a drywall saw or utility knife to cut along this line through the drywall. Make an additional cut out in the wall or ceiling to expose supply lines.

Pry off the cut drywall pieces carefully with a pry bar. Inspect the exposed plumbing lines and framing.

5. Detach and Remove Old Plumbing Fixtures

Locate the showerhead supply line and tub spout stub-out. Loosen any mounting hardware or unscrew fittings to detach them. For the tub drain, unscrew the overflow plate and remove the trip lever.

Unscrew the drainage pipe beneath. You may need to cut through connecting PVC/ABS with a hacksaw. Remove old supply lines.

6. Remove Remaining Drywall and Expose Studs

Chip away any remaining drywall covering studs using a hammer and chisel. Remove insulation.

Expose all studs and plumbing on sides down to top plates. This allows you to inspect for leaks, damage and access plumbing.

7. Take Out Old Tub

With the plumbing detached and drywall removed, the tub should be ready to take out. Slide a pry bar under the lip and pry the tub upwards while applying force downwards to break the seal.

Use a reciprocating saw to cut through any remaining vinyl or metal fasteners. Get a friend to help carry out the tub if needed.

8. Remove Flooring and Access Plumbing

If you plan to replace shower flooring, you may need to carefully pry up tiles, vinyl, or wood flooring around the old tub. Avoid damaging floor joists.

For drain line access, cut a hole around the drain stub-out with a reciprocating saw. Chip away concrete subsurface with a chisel and hammer.

9. Extend Drain Line and Replace Metal Flange

The existing drain line needs to be extended to just below where the new shower floor height will be. Measure and cut a length of PVC to connect to the drain stub-out.

Clean edges, prime, apply glue and connect the extension. Replace the metal drain flange too. Allow glue to cure fully before moving on.

10. Install New Shower Drain

The new shower drain assembly can now be installed. Apply plumber’s putty around the drain flange and press it into place. Hand tighten the drain collar piece.

On the inside, slide on the gasket and washer. Tighten the drain bolts with a wrench to seal everything in place.

11. Build Stud Frame for Shower Walls

Measure and mark out the stud frame for the size of your shower walls according to your model. Cut 2x4s to length.

Make the back wall frame first. Nail vertical studs between the vertical wall ends using 16d nails. Install cross bracing. Make the two side wall frames next.

12. Attach Waterproof Membrane to Studs

Before installing backerboard, you need to apply a waterproof membrane to studs. Roll liquid membrane onto the surfaces, or adhere precut sheets following product directions.

RedGard, Laticrete and Ardex are quality brands. Cover corners and seams thoroughly. Extend 6 inches beyond shower floor area.

13. Install Cement Backerboard on Shower Walls

Cut cement backerboard like Durock or HardieBacker to size using utility knife or shears. Fasten to studs with screws, keeping it 1/4 inch above shower floor height.

Use thinset to fill joints between backerboard sheets. The seams should be staggered. Tape and fill seams with thinset too.

14. Build Shower Pan Frame

Cut 2x4s for the floor frame so pan will be level and have proper slope. Connect the ends to wall studs. Add joist bridging support.

Mark the drain location on joists. Cut out a hole around it so pan can align with drain pipe.

15. Install Shower Pan Liner or Pre-fab Unit

For a custom tiled shower, install a shower pan liner molded to the floor frame. Fold up 6 inches on walls. Secure to studs temporarily with deck screws.

For a prefab unit, set it in place and level it. Some pans may require backerboard and waterproofing under it – follow manufacturer instructions.

16. Install Supply Lines to Mixing Valve

Plan proper placement for the shower mixing valve to make connections easier. Install 1/2 inch supply lines from main to valve area.

Solder copper lines or use PEX and fittings. Attach valve to lines following manufacturer directions. Do test fit with showerhead to ensure proper placement.

17. Install Backerboard on Ceiling

Moisture resistant backerboard should also be installed on the ceiling above the shower area. Cut pieces to fit between joists and fasten with backerboard screws.

Fill seams with thinset. Tape and thinset seams. Extend over shower walls seams.

18. Waterproof Shower Walls and Ceiling

With backerboard installed, waterproof shower walls and ceiling using liquid membrane following product directions. Apply carefully and avoid leaving gaps.

Alternatively, use waterproofing panels adhered with thinset. Extra membrane should extend over the shower floor frame.

19. Tile Shower Walls and Ceiling

It’s now time to apply the wall tiles. Mix thinset and apply to backerboard using notched trowel. Press tiles into thinset and space evenly.

Check your work with levels to ensure straight, even courses. Continue tiling ceiling and up to corner edges. Allow tiles to cure fully.

20. Install Shower Niche (Optional)

If your design has a recessed niche, cut an opening in waterproof backerboard with oscillating tool. Attach niche box securely.

Apply thinset to inside and tiles to surface. Use caulk to seal niche box edges against tile and let dry completely.

21. Tile Shower Floor

Thinset, spacers and tile needed for shower floor. For best results, start tiling near drain to ensure proper slope.

Continue laying tile in thinset outwards in straight rows. Inspect slope with level and use wedges to adjust as needed. Allow to fully cure.

22. Grout and Seal Tile

Mix grout and apply to shower walls and floor using float. Push into joints and wipe excess. Carefully grout niche and corners. Allow to dry.

Seal grout lines and apply a waterproofing sealant to surfaces for added leakage protection according to product directions.

23. Install Shower Door or Enclosure

The final step is installing a shower door or enclosure to complete the job. For frameless glass doors, install brackets and hardware first. Set glass in place and finish.

For rod systems, attach wall jambs and slide rods through. Insert door panels and install handles and locks if needed.

Frequently Asked Questions

How long does it take to replace a bathtub with a shower?

For an experienced DIYer, expect the tub to shower conversion project to take 2-3 full days. Demolition can be done in a day. Building the new shower framing and installing backerboard, waterproofing and plumbing may take 1-2 days. Tiling and installing the shower door can be done in a final day.

Can I convert a bathtub to a walk-in shower?

Yes, any standard alcove tub can be converted into a walk-in shower as long as there is adequate space. The steps covered above give an overview of how to change out a bathtub for a new shower.

Do I need a permit to replace a bathtub?

Building permits are usually required when replacing a bathtub, since the project involves plumbing work. There may also be local codes for shower size requirements, materials and waterproofing methods. Always check permit regulations with your local building department before starting.

How do I waterproof walls when replacing a bathtub?

Waterproofing is critical to prevent leaks and damage. Install a membrane like RedGard on all shower walls and ceiling before adding tile backerboard. Use a liquid applied membrane or adhere sheet panels. Ensure full coverage and overlap seams.

What is the best material to replace a bathtub with?

Tile is the most popular choice for walk-in shower walls and floor when replacing a tub. For a quick and easier conversion, fiberglass or acrylic shower kits are available. Vinyl shower liners can also work over existing tub surfaces as a budget option.

How do I frame a walk in shower?

Framing a walk-in shower involves building stud walls at least 2″x4″ to the size of your shower design. Attach vertical studs between vertical end studs and add cross bracing every 16″. Waterproof the framing before attaching tile backerboard to it.

What should the slope be for a walk-in shower?

A proper slope or pitch is crucial for shower drainage. Recommended slope is 1/4 inch per linear foot towards the drain. This means if your shower floor is 3 feet away from the drain, it should slope down 3/4″ over that distance. Use levels often when building the shower pan.


Replacing an outdated and cramped bathtub with a spacious new walk-in shower can give your bathroom an entirely new look and feel. By following the steps outlined above and using proper materials and waterproofing techniques, you can successfully complete this project as a DIYer. While the process is labor intensive, the end results will transform your bathroom into a relaxing oasis. With some perseverance and attention to detail, you can have the shower of your dreams!