How to Fix Water Damage Behind Shower Tiles Like a Pro

By: Diana Rodriguez-Zaba
Updated on: September 28, 2020

It’s easy to take the shower for granted. You use it every day, keep it clean and maintain fixtures with quick repairs. Over time, the walls of that inviting personal space can develop unsightly cracks and surround you with musty odors.

Water damage behind the shower tiles doesn’t happen overnight. It’s a slow process that results in long-lasting problems. However, there are DIY solutions. We keep shower tile sparkling across Chicago, IL, and the suburbs, so we’re happy to share our expertise.

This guide covers everything you need to know about repairing water-damaged shower walls.

Let’s dive in.

How Does Water Get Behind the Tiles in My Shower?

Most homeowners think of the shower as a waterproof environment. Ceramic tiles don’t absorb moisture, but the grout that fills tile joints is a cement-based product. If it isn’t sealed properly, grout allows condensation to form behind tiles. That damp eventually soaks into the wall.

Water seeping through grout in the shower often occurs in older homes. Until the 1990s, bathroom tile was commonly installed over drywall. The porous backer board absorbed moisture through gaps in tile grout or cracked tiles.

Bathroom walls in newer homes are usually constructed with cement board. This type of backer board is an improvement over drywall, but it isn’t a guarantee against grout failure.

What Happens When Water Gets Under My Shower Tiles?

As water collects behind shower tiles, it spreads moisture through the backer board. The material never dries because the tiles are attached directly to its surface. Eventually, the backer board begins to deteriorate, and that results in damage you can see and smell. These are five signs of water damage behind shower tiles.

1. Cracks, swells or discoloration in tile grout
2. Single tiles out of alignment with the existing grid
3. Tiles coming away from the shower wall
4. Peeling caulk around bottom tiles and the shower base
5. Pervasive, musty odors that don’t go away with cleaning

Pry a few tiles away from areas that seem to be water-damaged. If you see mold behind shower tiles, think twice about DIY repairs. You may be dealing with toxic black mold. Play it safe, and call in water damage professionals. Their technicians can determine the type of mold and safely handle removal, remediation and restoration.

How to Repair Water Damage Behind Shower Tiles in 7 Steps

water damage shower tile

Plan on this DIY job taking two or three days from start to finish. You need to allow time for materials to dry between steps. Before you start fixing your water-damaged shower walls, make sure you have the following tools and supplies.

  • Utility knife
  • Putty knife
  • Flat pry bar
  • Wallboard saw
  • Cement backer board
  • Cement board screws
  • Mesh joint tape
  • Thin-set adhesive
  • Tile grout
  • Notched trowel
  • Work gloves
  • Heavy fans

Once you’ve assembled the gear, you’re ready for these seven steps to repair bathroom wall water-damage.

1. Assess the Job

If the problem is directly behind an area of tiles, it’s probably the result of water seeping into the backer board. Tile damage around the shower base often indicates a plumbing leak behind the shower tiles. In this case, you may want to call a licensed plumber to take care of pipe repairs.

2. Carefully Remove Tiles

remove shower tiles

Using a putty knife or flat pry bar, carefully pull tiles away from the damaged backer board. Remove enough tiles to expose at least two additional inches of drywall surrounding the affected area. Soak the tiles in warm water and detergent so that they’ll clean up easier.

3. Remove Damaged Drywall

Using your hands, pull out the damp drywall in pieces. Use a utility knife or wallboard saw to remove another 2 inches of wall material around the damaged area. Remove exposed nails or screws.

4. Treat and Dry Wood Framing

Remove and replace any rotted wood. Scrub undamaged framing with a water and bleach solution. Otherwise, the wood can develop mold that spreads into your new backer board. Thoroughly dry wood framing by running fans in the room. This may take several days.

5. Install a Cement Board Patch

Start patching with cement board the same thickness as the original backer board. Using a utility knife, score and cut the patch. Size it to allow a 1/8-inch gap between the cement board and original wall material. Fasten the patch to the wall framing with cement board screws.

6. Tape and Fill Wall Joints

Apply a self-adhesive mesh joint tape between the original backer board and board patch. Be sure to use tape designed for use with cement board. Fill and feather seams around the patch with a thin-set adhesive and drywall knife.

7. Reset the Clean Tile

Using a notched trowel, evenly coat the wall with another layer of thin-set adhesive. Set the clean tiles, aligning joints with intact tiles. Once the adhesive dries, fill joints with a grout that closely matches the original. Protect the tiles and shower wall with a good tile grout sealer.

When Should I Call Water Damage Pros?

structural drying for mold

It takes some DIY experience to identify water damage, pull down tiles and replace backer board. If you’re not sure about handling the job yourself, think about the advantages of calling in water damage professionals.

  • Technicians diagnose and address the source of water damage.
  • Experienced teams handle tear-out, repair and restoration.
  • Certified specialists take care of mold removal and remediation.
  • Structural drying techniques reduce project completion time.

How Can I Prevent Water-Damaged Shower Walls?​

Your bathroom is one of the busiest spots in the house. You want to make sure your hard work holds up. These tips can help prevent future problems behind the tiles in your shower.

  • Avoid using harsh household cleaners, especially acidic products.
  • Control humidity by upgrading the bathroom’s ventilation system.
  • Open bathroom windows to fresh air whenever possible.
  • Routinely wipe down shower walls, and move damp towels to the laundry.
  • Reseal grout joints every year or two with a quality product.

Dealing With Water Damage Behind Your Shower Tiles in Chicago, IL, or the Suburbs? We’re Here to Help!

Sometimes, the job just seems too big. Taking care of it overloads your schedule, but you have to get it done. That’s often the case with water damage in the bathroom. We can help.

Our water damage services cover everything from repairs and reconstruction to mold removal. We handle all types of water damage restoration across Chicago, IL, and the suburbs.

We’re ready to take care of your home today. Just give us a call here at ServiceMaster Restoration by Zaba: 773-647-1985