Replacing a bathtub can seem like a daunting task, but with the right planning and tools it can be accomplished as a DIY project. A new bathtub can completely transform the look and feel of a bathroom. This guide will walk you through the entire process of removing an old tub and installing a new one.
Gather Materials and Tools Needed
Before starting any demolition, make sure you have all the necessary materials and tools on hand. This will make the project go much smoother and prevent unnecessary trips to the hardware store.
Materials
- New bathtub
- Drain kit
- Pipes and fittings
- Plumber’s putty or silicone caulk
- Construction adhesive
- Thinset mortar
- Tile (if retiling walls)
Tools
- Hammer
- Pry bar
- Reciprocating saw
- Putty knives
- Channel lock pliers
- Adjustable wrench
- Tube cutter
- Hacksaw
- Level
- Tape measure
- Utility knife
- Screwdriver
- Trowel
- Grout float
- Safety gloves and eye protection
Other Important Considerations
- Turn off the water supply and drain the pipes
- Remove any existing wall coverings around the tub
- Have all your materials ready before demolition
- Be prepared for this project to take 2-3 days
Remove the Old Bathtub
Removing the old tub is the first step in the replacement process. Take your time and work carefully to avoid damaging the surrounding surfaces.
Step 1: Turn Off Water Supply and Drain Pipes
Locate the shut-off valves for the hot and cold water lines that supply the tub. Turn them clockwise to shut off the water. Next, open the drain and remove the drain stopper to drain any remaining water from the pipes. Disconnect the drain pipe from the bathtub shoe and drain it into a bucket.
Step 2: Remove Fixtures and Accessories
Take off any wall-mounted fixtures like grab bars, racks or shelves. Remove the shower head, faucet handles and escutcheon plates. Take down any shower doors and rods as well.
Step 3: Take Out Wall Surroundings
Carefully pry off any tile or fiberglass surrounds on the walls around the tub using a pry bar and hammer. Wear safety goggles and gloves to protect yourself from debris. Try to remove the materials as intact as possible to make retiling easier.
Step 4: Detach and Remove the Tub
Start by unscrewing any metal rim or flange pieces securing the tub to the walls. Use a utility knife to cut through any caulk or adhesive sealing the seam between the tub and wall. Pry the tub away from the walls with a pry bar. Remove any nails or screws going into the floor around the feet of the tub. Carefully lift and maneuver the tub out, seeking assistance if it is very heavy.
Prepare the Area for New Tub
With the old tub removed, now you can make repairs and adjustments to ensure proper installation of the new tub.
Step 1: Inspect and Repair Subfloor
Examine the exposed subfloor for any water damage or weak areas. Use a level to check for levelness. Mix thinset mortar and apply to any dips or holes to create a smooth, level surface. Allow it to fully cure before continuing.
Step 2: Install New Drain Assembly
Place the new drain pipe and fitting into the hole and secure it according to the manufacturer’s instructions. Apply plumber’s putty around the drain basket and locknut underneath the tub, then tighten into place.
Step 3: Adjust Supply Lines
Measure and cut drain and supply lines as needed to fit with the new tub specs. Use a tube cutter for clean, straight cuts. Reconfigure supply lines and fittings as necessary.
Step 4: Prepare Walls for New Surround
If retiling, inspect the wall boards and repair any water damaged or rotten areas. Install cement backerboard prior to retiling around the tub. If using a surround or fiberglass unit, make sure the walls are smooth and clean.
Step 5: Apply Adhesive Mortar
Mix thinset mortar adhesive and trowel it onto the subfloor where the tub will sit. This creates a strong bonding layer. Follow the tub manufacturer’s directions regarding the thickness and coverage area for the mortar.
Install the New Bathtub
Now comes the exciting part – setting the new tub into place! Go slowly and double check your measurements.
Step 1: Dry Fit the Tub
Set the new tub into place without any mortar to ensure proper fit within the opening. Make alignment marks with a pencil where the tub meets the walls. Remove tub and set aside.
Step 2: Apply Mortar to Tub Underside
Flip the tub over and apply a layer of thinset mortar to the bottom (or follow your tub’s specific installation method).
Step 3: Set the Tub in Place
Carefully place the tub back into the opening using your alignment marks for positioning. Press down firmly to adhere the tub to the mortar base.
Step 4: Secure and Seal the Tub
Drill holes and drive screws through the rim of the tub into the wall studs to secure it. Apply silicone caulk around the seam and let dry completely. Install any decorative trim or flange pieces if desired.
Install Plumbing Fixtures
With the tub solidly in place, the next step is to connect the drain and supply lines. Then reinstall any fixtures that were removed initially.
Step 1: Connect the Drain
Attach the drain pipe to the shoe and tighten. Apply plumber’s putty if necessary to seal any gaps. Attach the drain stopper linkage and confirm proper drainage.
Step 2: Connect Supply Lines
Attach hot and cold supply lines to the proper fittings on the new tub/faucet. Use Teflon tape to seal threads and prevent leaks. Turn on water and check for any drips.
Step 3: Reinstall Fixtures
Put back any faucet handles, spouts, shower heads, grab bars, shower rods, doors and other accessories that were removed earlier.
Add Finishing Touches
The tub replacement is almost complete! Now you can surround the tub with beautiful new tile, walls, or a fiberglass surround.
Step 1: Tile the Walls (Optional)
If you are retiling, apply thinset mortar to the walls and lay the tile, using spacers for even grout lines. Allow to dry, then grout and seal the tile. Remove spacers after grouting.
Step 2: Install Surround Unit (Optional)
For fiberglass or acrylic surrounds, clean the walls well and apply adhesive. Carefully mount the surround panels per manufacturer instructions. Caulk along the seams and around edges.
Step 3: Caulk Along Tub Edges
Apply a smooth, continuous bead of silicone caulk along the seam where the tub meets the wall. Wipe gently with a damp cloth to smooth caulk and remove excess.
Step 4: Seal and Paint Walls
Seal up any unfinished drywall areas around the tub with waterproof drywall sealer. Prime and paint per your color scheme. Allow paint to fully cure before using tub.
Step 5: Clean Up the Area
Once everything is fully dry, do a final thorough cleaning to remove dust, adhesive, grout haze and any other construction debris. Now relax in your fresh, new bathtub!
Frequently Asked Questions
Still have some lingering questions? Here are answers to some of the most common queries about bathtub replacements.
How long does it take to replace a bathtub?
Plan for the bathtub replacement project to take 2-3 days from start to finish. The demolition portion takes about a day. Installing and setting the new tub, plumbing, surround and tile can take another 1-2 days.
Can I replace the bathtub myself?
With some plumbing knowledge and DIY experience, it is possible for homeowners to tackle a tub replacement on their own. Having an extra set of hands is ideal. Know your limits and when to call a pro if needed.
Does replacing a bathtub require a permit?
Most municipalities do not require permits for a basic tub replacement. But regulations can vary. Check with your local permit office to find out if any permits or inspections are needed.
What is the best material for bathtub replacement?
Cast iron, enameled steel, cultured marble, and acrylic are top choices. Consider factors like durability, cost, weight, and aesthetics for your needs. Acrylic is lightweight but scratches easier. Cast iron is extremely durable but very heavy.
Should I remove the drywall around a tub replacement?
It is best practice to remove drywall 6 inches above the rim of the old tub. This allows inspection for any hidden damage and ensures the new tub can be sealed properly to the studs.
How do I cut the drain and supply lines for a new bathtub?
Use a hacksaw or tubing cutter to cut the drain stub-out for the new shoe installation. For supply lines, determine the needed length and use a tube cutter for a straight cut. Re-bend lines as needed.
Conclusion
Replacing an old, worn out bathtub has the power to make a bathroom feel fresh and new again. With proper planning and preparation, this is a project a motivated DIYer can successfully complete. Focus on safety through every step of the process. Don’t be afraid to call in a professional if certain portions like the plumbing connections feel beyond your skill level. Taking the time to do the job right will result in a beautiful new tub you can enjoy for years to come. The improvement it makes to your home is well worth the effort!
