Remove an old plastic bathtub and surround and install a new bathtub and three piece surround with new plumbing and a tile border.
Time Multiple Days
ComplexityIntermediate
Cost$501-1000
Introduction
In this story, we'll walk you through a basic installation process, beginning with what is often the toughest part– tearing out the old tub and shower. Then we'll show you how to install and replumb the new unit. And finally, we'll show you a tiling technique that simplifies the finish work and makes the entire installation look great.
An acrylic tub and shower surround may not have the same appeal of an enameled cast iron tub and an elegant ceramic tile surround, but it’s a lot easier to keep clean and looking spotless. It wipes off quickly and has few joints to catch mold-attracting dirt and scum. And the unit is much easier to install. Most models consist of a tub plus three shower wall panels, which all interlock and seal. It’s the perfect item for a weekend bathroom upgrade. (OK, a full weekend.)
In this story, we’ll walk you through a basic installation process, beginning with what is often the toughest part—tearing out the old tub and shower. Then, we’ll show you how to install and replumb the new shower. And finally, we’ll show you a tiling technique that simplifies the finished work and makes the entire installation look great.
This project is a bit complex for a beginner. You should have some experience working with plumbing (P-traps and/or faucets) and basic carpentry tools. If you replace the shower valve and have copper supply lines, you’ll need soldering skills. Our tub/shower unit cost $300 (“Acclaim” by Sterling), and other materials (new shower valve, tile, etc.) cost about $200. This price tag could easily double with a higher-priced tub and surround and fancier valves. If you do it yourself, you’ll save the $1,000 cost of professional installation.
Begin by measuring the approximate length and width of your existing bathtub. Allow about 3/4 in. extra at each wall and your measurement should be close to one of the standard tub sizes. Most are 5 ft. long and 30 in. wide and are designed to fit against the wall studs. Then, shop for tubs and surrounds at home centers or kitchen and bath specialty stores. Then, order your tub. Acrylic replacement tubs are light enough for one person to lift in and out, even in tight spaces.
Beware of one piece bathtub shower surrounds and one-piece tub/shower stalls. They’re usually too bulky to get into an existing bathroom. Also pick up a new drain and overflow assembly, clear silicone kitchen/bath caulk and the other materials shown in the photos. This is also the perfect time to replace the old shower valve, spout and shower arm.
Tools Required
- 4-in-1 screwdriver
- Adjustable wrench
- Caulk gun
- Circular saw
- Cordless drill
- Drill bit set
- Grout float
- Hammer
- Hearing protection
- Hole saw kit
- Level
- Notched trowel
- Pipe wrench
- Pry bar
- Safety glasses
- Slip joint pliers
- Tape measure
- Utility knife
Materials Required
- 1-1/2-in. roofing nails
- 1/4-in. backerboard (1 sheet)
- Adhesive
- Backerboard screws (box)
- Caulk
- Grout
- New Tub and Surround
- Painting supplies
- Plumbing Supplies (as needed)
- Tile
- Tub/Shower Faucet
- Two 2x4x8
Project step-by-step (18)
Step 1
Remove the faucet, tub spout and showerhead
Before beginning, spread a thick canvas dropcloth over the bathroom floor and any nearby fixtures. Find the shutoff valves for the tub—usually behind an access panel in an adjacent room—and turn off the water. Then turn the tub faucet on to make sure the shutoffs actually work. If water continues to drip out, turn off the main water supply and replace the shutoffs.
Now, remove the faucet hardware. Most faucets are held by screws. Look for an Allen screw in a recess under the tub spout. If it doesn’t have one, it’s probably a spout that you unscrew (counterclockwise) with a pipe wrench. Wrap a rag around the jaws if you’re planning to save or reuse the spout. Unscrew the shower arm with the pipe wrench, too.
Step 2
Tear out the old bathtub surround: Cut through the drywall
To reduce hassles later, check the dimensions of the new tub surround (including the nailing flanges) before you cut out the old surround or tile wall.
Make your cuts about 1 in. larger than the “rough-in” dimensions of the new tub surround. Cut through the drywall around the tub and down to the base trim. Cover or disconnect the tub drain to keep the waste line from filling with debris.
The utility knife scoring method we show here takes some strength, but it avoids the problem of cutting into insulation and hidden wires and pipes. If you use a drywall or keyhole saw, cut carefully and keep the cut shallow.
Step 3
Pull the drywall and tub surround from the studs
Pull off the drywall with a hammer and pry bar, working from the edges. Keep an eye out for wires and pipes.
Step 4
Pull the tub surround away carefully
Keep your arms and face clear of sharp edges.
Step 5
Tear out the back section
Pull the tub surround panel free if the drywall is stubborn, then go back and remove the drywall.
Step 6
Remove the final panel
Remove the cut out drywall after pulling away the last pane. Remove any screws or nails from the exposed studs.
Step 7
Disconnect the waste lines from the tub
Open the access panel in the adjacent room and loosen the slip nuts connecting the old overflow and drain to the trap. Use slip-joint pliers, if necessary.
Step 8
Lift one end and remove the tub
Cut the apron at one end (plastic tubs) with a jigsaw, slice the caulk along the floor, remove any fasteners, and lift the tub up and out.
Steel tubs are tougher; you may have to remove drywall and slide them out, although you can often tip them up and out too. Cast iron tubs are too heavy to lift out. Break it up with a sledge. You have to slide in new cast iron tubs.
Step 9
Install 2×4 nailers
Cut 2×4 nailers the length of the opening and slip them behind the drywall edges. Drive 1-1/4-in. screws through the drywall to anchor them. Restore the insulation and vapor barrier.
If you have mold, scrub it away and let the area dry thoroughly before covering it with insulation and a vapor barrier.
Step 10
Check for tub level
Unpack the new tub and set it into place. Before you begin the bathtub installation, check the tub rim for level, both front to back and side to side.
The nailing flanges on plastic tubs are not meant to bear weight, so the tub legs must have a solid, level bearing on the floor. Shim spaces less than 1/2 in. with hardwood, metal or plastic spacers (don’t use softwood for tubs with small legs because the wood will crush). For thicker shims, use boards or strips of plywood. Use wide spacers and nail or glue them into place at the leg locations so they won’t shift when the tub goes in.
On larger tubs, the manufacturer may ask you to set the tub in a wet mortar bed, which will mold to the tub bottom and provide extra support.
At this point, note how the apron (outer edge) of your new tub meets the existing floor. Now’s the time to plan this joint, while you can still remove the tub. If you’re lucky, the new tub will meet the floor almost like the old one. But you may have a larger gap, or you may have to trim back the finish flooring to get the tub to fit.
Solutions vary with the type of floor you have and the gap size. One solution for a gap is to cover the joint with a thin solid-surface or marble threshold strip. Use silicone to glue it to the tub or floor, and caulk the edges along the tub and floor.
Before installing the tub, add the new drain shoe while it’s still easy to reach. Lay a thick ring of clear silicone caulk under the rim, and screw it together following the tub manufacturer’s instructions.
Step 11
Fasten the tub to the studs
Fasten the tub to the studs. Shim gaps between the studs and the flange to avoid stressing the rim. Protect the tub with heavy cardboard as you nail.
Step 12
Install the surround: Set the back panel first
Set the back section of the surround on the tub rim, holding it in place temporarily with a nail above the top flange. Then, set the side panels. The manufacturers allow a little play here, but not much.
Chisel back any warped or out-of-plumb studs to keep the panels sitting flat on the tub rim. You can add a shim later if you find a gap.
This is where setting your bathtub perfectly level pays off! The panels should align within about 1/8 in. If not, recheck your tub for level.
Step 13
Carefully measure for the faucet and spout
Center and install the new shower valve and copper lines. Then, measure the exact centers of the tub spout and valve and lay them out on the end panel. Drill the end panel holes.
Step 14
Fasten the panels
Set the panels and interlock them with the tub and adjust them until the tops are even. Then predrill and fasten the flanges at each stud. Add shims to fill gaps and keep the flange straight.
Step 15
Fill the gaps between the wall and panels
Making a nice wall finish around the new surround requires special attention to detail. Because of the thickness of the flange, use 3/8- or 1/4-in. backer board to keep the surface flush with the drywall.
In addition, we chose to tile around all the edges to cover the joint and avoid a difficult taping job. The thin backer board is fragile in narrow strips; predrill and fasten it to the studs with the special screws designed for backer board. Hold it back about 1/8 in. from the edge of the surround.
Step 16
Tile and grout
Clean and prime-painted walls before tiling the bathroom wall around the tub. Then, set the tile, working from the outside corners on the end walls and from the center on the back wall for a symmetrical layout. Caulk the tile/tub joint the day after you grout.
Step 17
Install the plumping
Now, finish the plumbing. Spread a bead of silicone around the edge of each hole in the surround and install the faucet plate and tub spout. (Avoid bowing the surround inward when tightening.) Cut the new drain line and overflow to length and hook them up to the P-trap and tub. Then, run water into the tub to test for leaks.
Step 18
Dealing with Old Pipes
Finding old steel pipe in the wall doesn’t mean you have to replumb the entire house. You can make a transition from a galvanized water supply pipe to copper or plastic (CPVC). For copper, use a special dielectric coupling—a fitting that prevents corrosion. If you have steel drainpipes, use a special “mission coupling” to transition to plastic drains. All these fittings are available at hardware stores and home centers in many sizes.
