How to Install a Soaking Tub Into a Walk-in Shower

Prep Work

• 1

  Measure your soaking tub. Add 8 inches to the length and 8 inches to the height, because you will need to build a surrounding deck for it that extends outward by 4 inches on each side. Measure your walk-in shower. If you have a large one or one that is open on two sides, you can install the soaking tub without needing to take down walls. If you must remove walls, consult a contractor or building inspector first to be sure you won’t remove needed support for the ceiling.

• 2

  Remove the tiles on your walk-in shower wall around your shower controls and below, all the way to the floor. Draw the grout cutter down the lines of grout in strong, even sweeps. Once the tiles loosen, pry them up with the screwdriver. Cut through the exposed cement board with the utility knife so you expose the water supply pipes in the wall. Remove the tile on the floor of the shower that the soaking tub and the surrounding deck will cover.

• 3

  Cut out a 12-inch wide section of the subfloor running from the shower wall to the shower drain with the hack saw. Remove the p-trap from the drainpipe in the floor. Add a new length of PVC pipe to the floor drainpipe, connecting it with the PVC connector and glue. Run the new drainpipe to where the tub drain will be located. Reconnect the p-trap. Cut a piece of ¾-inch plywood with the circular saw to patch the hole in the subfloor. Cut a hole in the patch for the drainpipe. Screw the patch onto the floor joists using the drill. Draw an outline on the floor with the pencil of the shape of the frame for the tub surround.

• 4

  Turn off the water supply to the bathroom. Remove the shower control valves from their stems. Typically, they just twist off. Use channel pliers to remove the stems from the water supply lines. Remove the section of pipe that connects the hot and cold water supply lines to the line going up to the faucet with the wrench. Replace it with a new section of pipe that has a connection for a tub faucet. Tie in a tub faucet nipple that reaches down to where you’d like to have the tub faucet protrude from the wall.

Installing the Tub

• 5

  Cut eight 2-by-4s for the frame of the tub surround. Cut four to the length you measured, and four to the width minus 8 inches. Nail four of the 2-by-4s to the subfloor, following the outline you created.

• 6

  Measure the distance from the floor to the underside of the tub lip. Take that distance and subtract 4 inches for the frame, 1 inch for plywood and 1 inch for cement board and tile. Cut braces out of 2-by-4s with the circular saw to that length. Screw the braces to the frame boards on the floor. Then screw the long frame's 2-by-4s to the top of the braces.

• 7

  Cut the ¾-inch plywood down with the circular saw so it covers the top of the surround frame. Screw it into the frame with the drill. Place a cut-out for the tub on top of the plywood and trace around it with the pencil. Cut out the plywood inside the tracing with the reciprocating saw.

• 8

  Assemble the drain-waste-overflow kit according to the manufacturer’s instructions. It connects the soaking tub’s overflow plate to the tub drain and will connect both of them to the p-trap and the main drain line. Connect it to the tub, then lift the tub and drop it down into the cut out on the deck. Connect the drain-waste-overflow to the p-trap and install the drain fittings that came with the tub.

• 9

  Cover the deck with the cement board, drilling it into place. Use cement board to enclose the shower wall. Tile the deck with the thinset mortar and the tile of your choice. Cover the shower wall in tile as well. Install the new tub faucet and controls according the manufacturer’s instructions.