A high-quality bathtub defines the look and function of your bathroom. Given the cost of labor (which can range to as high as $2,000), many homeowners opt to take the DIY route. Replacing a bathtub yourself isn’t recommended unless you have experience. But with an average tub replacement cost of over $5,000 as of 2023 (up to $13,000 or more on the high end), how you handle DIY bathtub replacement can make or break your investment.1
Can I Replace My Own Bathtub?
Yes, with the proper knowledge and preparation. The first step to DIY bathtub replacement should be selecting a new tub. To choose one, measure the alcove in your bathroom. A standard bathtub is 5 feet long and 30 or 32 inches wide. Make sure the tub is as close in size as possible to your measurements.
Then select a replacement tub based on where the drainpipe is. You’ll need a left-draining tub if the drainpipe is on the left side; if it’s on the right, you’ll need a right-draining tub. Next, determine the type of material, such as:
- Fiberglass: Fiberglass tubs are generally the most affordable (however, refinishing one can be pricey). They’re lightweight and come in different colors, but they don’t retain heat very well.
- Ceramic: Ceramic tubs come in a wide range of colors and styles, but be prepared to clean grout and repair chips to maintain your investment.
- Acrylic: Lightweight and durable, acrylic provides aesthetics plus resistance to scuffing and damage from toys. A standard acrylic tub can be under $1,000, but a high-end model can reach $14,000.1
- Steel: Enameled steel has the classic look of cast iron but is less expensive to refinish than fiberglass
- Copper: Copper is durable and long-lasting, holds in heat, and is resistant to bacteria and mold growth.
- Granite: Modern, durable, and long-lasting, a granite bathtub can cost up to $20,000.1 This high-end option is heavy and one of the most challenging to install.
Consider the type of tub as well. Do you need a basic general-purpose tub or a clawfoot, freestanding, or walk-in tub? Other options include deep-basin soaking tubs and jet/whirlpool tubs. Accessible bathtubs have a wider entryway, a door for entry, and a larger footprint than a standard tub.
Prepare the Work Area
DIY bathtub replacement is somewhat of a messy job. Be sure to wear work gloves, protective eyewear, and hearing protection. You’ll also need to dispose of your old tub. Check your local sanitation company or recycler for regulations on disposal and whether they offer assistance. Fiberglass tubs are easier to remove than steel, cast iron, or porcelain which may need to be broken apart with a sledgehammer before being hauled out.
Consider Extra Steps/Costs
Don’t leave out any details when planning a DIY bathtub replacement. Some steps homeowners often forget to consider are:
- Removal/Disposal of the Old Tub: The requirements vary depending on the type of tub and local regulations. You may have to pay for tub removal, which can range from $100 to $4,200.1
- Subfloor Replacement/Preparation: You’ll have to replace the subfloor (for about $3 to $10 per square foot1) if there’s water damage, rot, or deterioration. And if installing a heaver tub, you may have to also reinforce it.
- Plumbing and Bathtub Extras: Updating and moving plumbing lines may require additional flexibility in your budget, especially if you have old pipes or want to relocate the tub. Faucets, which come in different materials and styles, and surrounds that range from basic surfaces to waterproof panels, also cost extra.
- Permits: When your DIY bathtub replacement involves relocating pipes and electrical wiring, you’ll need a building permit. The cost of each permit can be several hundred dollars. Depending on your location, obtaining a permit may require hiring a contractor.
Turn Off the Water Supply
Use the shutoff valve for the tub or bathroom; if there isn’t one, turn off the water supply to your home. Turn a bathtub faucet on to make sure no water is running. Next, open a valve at a lower level to relieve pressure. . While the bathtub itself isn’t connected to a water line, this protects against water damage should you accidentally bump into a valve later.
How Do You Remove an Old Bathtub?
Removing the old tub is a multi-step process but essential to DIY bathtub replacement. To successfully do so:
- Disconnect the Drain Flange/Overflow Cover: Unscrew the drain stopper if there is one, and remove the drain flange with a tub drain wrench. Then remove the waste and overflow valve cover using a screwdriver. Next, you can remove the tub spout by removing the set screw or twisting the spout counterclockwise.
- Remove the Drain Assembly: Disconnect it from the plumbing by accessing the underside of the tub. Use the access panel or cut away a piece of drywall if there’s no panel. Disconnect the drainpipe, below the tee, with channel lock pliers. If there are galvanized steel fittings, a penetrating lubricant will help loosen the joints. Once the drainpipe nut is loosened, unscrew it and remove it by hand.
- Remove the Tub from the Wall: Remove drywall and other material to about 6 inches deep (using a drywall saw). Work until you reach the wall studs. Fiberglass tub surrounds will have to be removed first. Wearing safety equipment, cut out a section of the wall on three sides and along the front of the tub. Start about 6 inches above it.
When removing the tile, pencil a guideline using a straight edge. Remove the tile using a grout remover tool and pry it away with a stiff putty knife.
The following tips should help make this step easier:
- Remove the cement backer board with a utility knife to reach the stud.
- Use a pry bar to remove screws, nails, and trim all the way around.
- Use a utility knife to cut away caulking between the tub and the floor.
- Remove and Dispose of the Tub: Two people should work together, one lifting the tub from the front and another sliding 1 x 4 boards below it. These boards are used as skids to slide the tub out of the alcove. Remove any remaining stringer supports on the wall and clean the area.
If the tub is made of lightweight material or porcelain enamel steel, dispose of it as a whole. Use a sledgehammer to break up a cast iron tub or a reciprocating saw to cut up steel, composite, or fiberglass tubs.
How Do You Install a Bathtub?
When you’re ready to begin the final steps of DIY bathtub replacement, check the new tub for damage and protect it with a section of cardboard from the package; cover the interior and exposed side. Place the leveling/sound-insulating pad on the tub’s underside, which will rest on the subfloor. Use a floor leveler to even out the subfloor if necessary.
The tub is now ready to place into the alcove. Make sure it’s level, use shims to even it out, and then mark a reference line with a pencil on the studs. This line should reach around three sides. Move the tub, set it aside, and proceed with the following steps (may vary depending on the type of tub and material, so check with the manufacturer or a contractor):
1. Install a 2 x 4 Stringer
The stringer attaches directly to the studs to support the tub. Measure the flange’s height and measure the distance below the reference line drawn to indicate the top edge of the stringer. Now cut the 2 x 4 the length of the tub and attach it to the studs with deck screws.
2. Install the Overflow Drain Assembly
Turn the tub on its side and follow the manufacturer’s instructions for installing the drain. Place the plumber’s putty on the underside of the drain flange and then position the drain shoe on the underside of the tub. Screw the drain flange into the threads and tighten it with a drain wrench tool.
Next, remove excess putty and connect the overflow valve by placing a rubber gasket onto the overflow elbow. The cover plate in the tub connects to the elbow using the provided screws. Use a tee to connect the overflow and drain pipes, then attach the drain strainer to the flange.
3. Attach the Drain:
Move the tub into its final position. As you place it, avoid hitting the drain assembly, and make sure the flange rests on the stringer along the back wall. Check the alignment between the drain/overflow plumbing from the tub and the drain outlet. Connect and tighten the pipes (don’t over-tighten them).
4. Complete the Tub Installation
Check that your reference marks and the flange line up. If they do, hold the flange down with a fastener as you secure it on three walls. It’s best secured with roofing nails or galvanized screws. Now, you can install drywall, tile, or tub surround and perform any other finishing necessary. Lastly, reattach the spout, turn the water back on, and wait at least 24 hours before using the tub.
How Long Does It Take to Replace a Bathtub?
On average, a DIY bathtub replacement should take about four hours. That excludes plumbing work and other repairs that might be needed. You can replace a bathtub in under a day, but consulting with a professional is a good idea to ensure the work is done correctly.
Call Village Plumbing & Air for Help
Our experienced plumbers provide a full range of services to homeowners in the Houston area. If you need professional assistance during your DIY bathtub replacement project, we’re here to help. We offer a 100% satisfaction guarantee, coupons, and financing. To schedule a consultation or bathtub installation near you, request service online or call 713-526-1491.