How to Convert an Acrylic or Fiberglass Shower to Ceramic Tile

A workman tiling a shower

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Overview
  • Working Time: 20 hrs
  • Total Time: 72 hrs
  • Skill Level: Advanced
  • Estimated Cost: $200 to $1,000 or more

Low-cost alcove showers are often made with acrylic or fiberglass surround panels, which are installed over a shower floor consisting of a prefabricated acrylic base. Those surround walls are perfectly serviceable, but they are essentially plastic and thus not all that attractive. At some point, you may want to replace those low-cost surround panels with something more stylish.

Turning an old fiberglass or acrylic shower alcove into a custom-tiled shower is easier than you think. The process involves leaving the current shower pan in place, but removing the wall panels and replacing them with ceramic tile surfaces. This can save you considerable time and cost over demolishing and replacing the entire shower, since there's no drain connection or tricky work of setting a new shower pan. The same process can be used if you have surround panels above a combination bathtub/shower alcove.

Anatomy of a Tile Shower

Installation of ceramic tile on the walls of a shower alcove is much like tiling any wall surface, but because these areas are subject to constant moisture, you need to take special precautions to seal the wall against moisture penetration. Ceramic tile should never be applied directly to drywall in any situation—and especially in a shower, where moisture is likely to penetrate eventually.

The traditional method of tiling shower walls, demonstrated below, is to apply plastic sheeting against the wall studs. Over the plastic water barrier, standard waterproof cement board backer panels are installed, with the cracks between panels sealed with waterproof joint tape and thin-set adhesive. From here, installation of tile proceeds as for any ceramic tile—the tiles are glued to the backer board with thin-set adhesive, then grouted with a mortar-based grout, and sealed with a liquid sealer.

Tip

A new form of backer board is also available that allows you to bypass the plastic sheeting water barrier. Sold under brand names such as Denshield, these products have a waterproof membrane built into the panels. The seams are then sealed, and ceramic tile is applied with thin-set adhesive. This form of backer board is now preferred by professionals, since it speeds installation.

Skills Required

Tiling shower walls is really no harder than any form of ceramic tile installation—which is to say that it is a moderately advanced project. Tiling walls is somewhat more difficult than tiling floors, and careful layout of the tile job is essential in the tight space of a shower alcove. There is a considerable amount of tile cutting required, and drilling holes in tiles for shower fittings is frequently necessary. This is a project best suited for DIYers who have had successful experience with tiling and who have a good degree of patience.

But DIYers willing to tackle the job can enjoy considerable cost savings, as the primary cost of a professional installation lies in the labor, not the materials.

What You'll Need

Equipment / Tools

  • Demolition tools
  • Utility knife
  • Stapler
  • Tape measure
  • Circular saw
  • Drill with driver bits
  • Smooth-edged trowel or drywall knife
  • Level
  • Pencil
  • Straightedge
  • Notched trowel
  • Tile snap cutter or wet saw
  • Diamond hole saws (as needed)
  • Rubber grout float
  • Grout sponge
  • Bucket
  • Foam paintbrush

Materials

  • 4- or 6-mil plastic sheeting
  • 1/2-inch cement backer board
  • Cement board screws
  • Thin-set adhesive
  • Cement board joint tape
  • Ceramic or porcelain wall tile
  • Masking tape
  • Tile spacers
  • Silicone tub-and-tile caulk
  • Grout
  • Cloths
  • Grout haze remover (optional)
  • Grout sealer

Instructions

  1. Strip the Walls to the Studs

    Remove everything in the shower alcove down to the studs. Begin with the faucet parts and other hardware, then move to the surround panels. You may need to cut out the drywall 1 1/2 to 2 inches away from the panel edges to expose the nailing flange of the surround panels. Other panels are simply glued to the drywall and can be pried off with a flat bar or pulled off along with the drywall. Make sure all studs are free of nails and other protrusions.

    Check the studs with a level and straightedge to make sure they are plumb and that the front faces are flush with one another. Some work may be necessary to create a flat, plumb surface for the cement board backer panels.

  2. Install a Moisture Barrier

    Staple sheets 4- or 6-mil plastic sheeting over the studs to serve as a moisture barrier. Make sure the vertical seams between sheets overlap by at least 3 inches and that the bottom of the plastic slightly overlaps the edges of the shower pan. Properly installed, the moisture barrier will direct any water that penetrates the tile surface down into the shower pan.

  3. Install Cement Board Backer Panels

    Cut and attach 1/2-inch-thick cement board backer panels  to the studs. Cutting panels can be done with a circular saw or by scoring and snapping the panels. Screw the board to the walls with cement board screws, leaving a 1/4-inch gap between panels, then tape and mud the seams using thin-set adhesive applied with a smooth-edged trowel or drywall knife. Also tape and mud and tape the joints where the cement board meets the surrounding drywall. If the tile job meets drywall at the top rather than running all the way to the ceiling, the front face of the cement board should be flush with the drywall.

  4. Mark Layout Lines

    Using a level and straightedge, make vertical and horizontal layout lines on the cement board. Make sure you mark a horizontal line at the bottom of the wall to indicate the location of the first row of tiles. Leave a 1/4-inch gap between the tile and the shower pan, which will serve as the caulk seam.

    Also mark a vertical centerline at the center of each wall. Test fit the bottom row of tiles, using masking tape to adhere the tiles to the wall. If necessary to achieve a pleasing layout, you can now adjust the vertical layout line to the left or right. This adjustment can eliminate the need to cut thin segments of tiles at the sides.

  5. Install the First Row of Tiles

    Mix a small amount of thin-set adhesive, as directed, mixing just enough for the first row of tiles around the perimeter of the shower pan. Use a notched trowel to apply an even coat of thin-set to the wall below the marked lines.

    Apply the first row of tiles to the wall, using the layout line to maintain a level row. Use plastic spacers to maintain uniform gaps between tiles. Firmly press the tiles to the adhesive; they should stick without any other aid.

    Partial tiles can be cut with a ceramic tile snap cutter, or with a power wet saw, available for rent at home improvement centers and tool lease outlets.

    Let this row set for at least half a day, because it must be firmly anchored as you work upward to install the rest of the tile. As the adhesive firms up (20 to 30 minutes) remove the plastic spacers between tiles.

  6. Continue Tiling Upward

    Install the remaining rows of tile using the same techniques used for the first row. Use tile spacers to maintain uniform horizontal and vertical seams between rows. Continue to the top of the tiled area or to the ceiling, as desired. If you're stopping below the ceiling, use bullnose tile for the top row to create a finished edge.

    Where you need to cut holes in tiles for shower faucet or showerhead stub-outs, a hole saw with abrasive diamond cutting edges is the best tool.

    After the tile adhesive sets for 20 to 30 minutes, remove the plastic spacers between tiles. Let the tile adhesive set for 48 hours before grouting.

  7. Grout the Tile

    Mix a batch of grout as directed by the manufacturer. (Be sure to choose a type of grout with a color that complements your tile.) Use a grout float to apply grout across the face of the tile and press it into the open joints between the tiles. Multiple passes of the grout float may be needed to fully fill the joints. On the final pass, use the edge of the grout float to remove as much excess grout as possible. Scraping diagonally across the joints is the best technique for removing excess grout.

  8. Clean the Tile Surface

    Wipe across the tiles again with a grout sponge dipped in clean water and wrung out very well (it should be just damp) to clean the tile faces and further smooth the grout joints. Wipe diagonally to prevent pulling grout from the joints. Let the grout cure as directed.

  9. Remove Haze

    When the grout is dry to the touch, buff the tile with a clean cloth to remove the whitish haze left by the grout. You can also use a grout haze remover to speed up the work and to remove any stubborn grout or stains.

  10. Seal the Joints

    Seal the grout joints with a grout sealer, using a foam brush as an applicator. Wipe away excess sealer on the face of the tiles using a dry cloth.

    Although this sealing step is sometimes omitted, it is recommended to help prevent staining and to make the grout easier to clean. Sealing is especially useful in a shower installation, where mildew is a frequent problem.

  11. Caulk

    Seal the gap between the bottom row of tile and the shower pan with pure silicone caulk. Let the caulk dry for 24 hours before using the shower.