Water Damage Behind Shower Wall. Tips from professionals

Your shower is designed to get wet, but only on the outside of the wall. When moisture is trapped under tiles, it may create many issues. If left too long, it may ruin the drywall or other backing, create rot, and even cause the tiles to crack or break. In the worst-case situation, water damage underneath your tiles might result in mold growth.

Water Damage Behind Shower Wall

If you notice any signs of water damage behind the shower wall, the first step is to determine the cause. Check your shower tiles to see if they are firmly in place and for cracks in the tile grout. The problem can come from the shower area or from outside. Fix the leak causing the water damage and check for mold.

This article will provide you with in-depth details about water damage behind the shower wall and how to detect it. I will explain how you can tell if your shower wall is damaged and answer some frequently asked questions about mold and how to dry a shower wall.

Can You Detect Water Damage?

Apparent water damage signs such as water dripping through cracks on the tile grouts on the shower walls and floor are easy to spot. In other cases, a leak can show itself in ways that are more difficult to identify, such as:

• Musty odor
• Insects/termite infestation
• Cracks, discoloration, or uneven tile grout.
• Mold and mildew growth.

Remember that water damage beneath shower tiles sometimes occurs gradually and subtly. That means that before you even notice it, some of the damage has already been done. This is why I recommend regularly checking your shower walls and floor for leakages. If you suspect it is from a leak, dry your wall completely, and check again.

What happens if water gets under tile in the shower?

Ideally, grout controls seepage by securing tiles to the base. Grout is a combination of sand and water with cement or lime used to fill up the gaps between tiles attached to your bathroom floor and walls. If it gets loose, cracked, or damaged, then water and moisture can make their way underneath your tiled floors.

There can be considerable damage to your bathroom floor and walls when that happens. You will notice your shower tiles loosening from their subsurface. This is common when water finds its way underneath the bathroom tiles. The trapped moisture loosens the mortar that holds the tiles to the floor or wall and causes them to lift away.

Additionally, the excess water will cause the subflooring to swell, warp and push the bathroom floor tiles up.

How do you fix water-damaged shower walls?

As soon as you notice water damage to your shower walls, you need to identify and repair the water source damaging your bathroom wall. If the source of the water damage is not fixed, fixing the wall does not make any sense.

The source of the leak can be a damaged pipe or coming from the roof. In many cases, it is challenging to find the culprit. Knowing where pipes are located can be a great help. You can use a metal wall scanner to check for this. If the wall with the damage is an outer wall, the water may come from outside. Similar if the ceiling is also the roof of the house, it can be a problem with the roof.

Always understand that water finds its way to the lowest point. This means that the leak itself may not be close to the point where you see the damage.

When the leak is fixed, you can use the following steps to repair tiled drywall:

• Step 1: Remove the damaged tiles
• Step 2: Remove the floor-to-ceiling molding to allow you to replace the trim
• Step 3: Look for the nearest closet stud, and using a straightedge, draw a vertical line from the center of the next closest stud to the top edge of the damaged drywall. Similarly, connect the top, bottom, and left and right sides of the damaged region.
• Step 4: Cut out the damaged drywall.
• Step 5: Replace any rotten studs
• Step 6: Replace the drywall that was removed
• Step 7: Screw holes and seams should be filled with caulk
• Step 8: Paint the drywall after applying drywall mud to the wall
• Step 9: Remove and replace the old tiles with new tiles

Mold behind plastic shower walls

If your shower has a plastic shower wall, it will generally not show any damage on the outside. But that does not mean there is a problem inside the plastic shower wall. Mold and bacteria thrive in a warm, moist environment poses a health risk to you and your family. Removing the mold between the plastic shower wall and the substrate can be highly challenging.

When the plastic shower wall is easy to remove, you can do this and clean the substrate and the inside of the plastic shower wall. You can use 1 part bleach and 3 parts water for removing mold or another mold cleaning solution.

If the substrate is challenging to reach, you can use bathroom disinfectants to get rid of mold behind the plastic shower walls. Try to spray it from the edges of the plastic shower wall. Commercial bathroom disinfectants can successfully kill all varieties of bathroom mold, but normal home bleach is just as efficient. If you do not know how to remove mold or the area is hard to reach, ask a professional for help.

Maintain a mold-free shower by applying a simple weekly treatment to the walls and surroundings. Clean the walls weekly by spraying them with an anti-mold solution. Mix of 1 part bleach to 2 parts water.

Water leaking behind tiles in shower

Water leaking behind tiles in your shower generally comes from a source inside or above the wall. Or from water from inside the shower area.

● Water leaking from inside the shower area

Water from inside the shower can leak through the tiles and find its way behind it. The most common reasons are:

• Grout: Missing or cracked grout. If the wall can flex a little bit, it can damage the grout over time.
• Silicon: Incomplete or broken silicon seal. This can find its reason in the wrong fitting of the shower tiles, or if the wall can flex a little bit. Also, the part where the wall meets the floor is a common location.
• Substrate: Using a non-waterproof substrate wall

● Water coming from the outside or above the shower area

The second reason for water leaking behind the tiles in your shower is water coming from a leak in the roof or wall or a cracked pipe. In many cases, the source of these leaks can be hard to find. The amount of water leaking is often small, and the source can be further away as water can travel some distance.

If you suspect the source is a leaking pipe, knowing where pipes are located can be a great help. Use a metal wall scanner to check for this. You can purchase them in most hardware stores.

If the wall with the damage is an outer wall, the water may come from outside. Similar if the ceiling is also the roof of the house, it can be a problem with the roof.

● Signs of water leaking behind tiles in a shower

If you suspect a leak behind the shower tiles, there are a few things to look for:

• Peeling paint: If the paint on the walls around your shower is peeling, it can be a sign that there might be a leak beneath the tiles.
• Loose or cracked tiles: Another signal of water leaking behind tiles in your shower is loose or peeling bathroom tiles. When the substrate becomes full of water, it can increase its volume and move the tiles. Or it becomes weaker, and the tiles can move a little bit and crack.
• Mold: If you notice mold, it is a sign of moisture. It does not always mean a leak, but it is a good reason the thoroughly inspect the shower area. If you do not find a leak, remove the mold, and ventilate.

How can you tell if a shower wall is water damaged?

Water getting behind your shower tiles can damage your shower walls and substrate over time if the seepage or leakage is not fixed in time. You can tell your shower wall is damaged by water if:

• Missing or cracked grout: If you notice that the tile grout is cracking or even missing, swells, or shows a discoloration, it can be a sign that there is a water problem. Of course, grout cracking or missing can also be due to the flexing of the wall.
• Tiles out of line: You observe that single tiles are out of line with the current grid.
• Loose tiles: The tiles look to be separating from the shower wall. Often this starts first with grout issues.
• Caulk: You observe caulk peeling around the bottom tiles and the shower base.
• Odor: You clean the bathroom but notice the pervasive musty odors that don’t disappear.

How do you tell if there’s mold behind shower tiles?

Mold can grow in your shower in two main ways, on the surface or behind the shower tiles. Mold on the shower tiles is much easier to spot can clean. To know if there is mold behind the shower tiles is much more challenging to see, and you have to look for certain signs:

• Muddy spots on the tiles: It can be a sign of mold behind the tiles if you notice muddy spots on the shower tiles. The tiles can be slimy moist, indicating black mold forming underneath the shower tiles.
• Signs on the plaster: The plaster on your bathroom walls starts to show signs of damage, such as crumbled texture with walls discoloring and the paint coming off the walls.
• Cracked or loose tiles: You can also find cracked or loose tiles in your bathroom. This can indicate a water issue behind the tiles. This water issue can result in mold growth if the conditions are suitable.
• Odor: Presence of a continual musty smell in your bathroom despite cleaning your shower regularly. The odor is usually caused by the formation of black mold beneath the shower tiles. Black mold emits spores that cause items to decay and smell.

How to Prevent Mold in the Bathroom

You can use the following tips to prevent mold in your bathroom walls and floor:

• Tip 1. Dry your bathroom: Always dry your bathroom thoroughly after use. Dehumidifiers and exhaust fans are two options for managing humidity in the bathroom.
• Tip 2. Ventilation:Make sure you ventilate the bathroom well. This removes the moisture. If you have a fan, use it. Leave it running for some time after taking a shower. If you do not have an inbuilt fan, consider getting one.
• Tip 3. Remove wet items: Hang your wash rag, loofah, or sponge to dry. Avoid leaving wet your items sitting on shower surfaces as they’ll trap water and take longer to dry out.
• Tip 4. Clean regularly: After using the bathroom, make sure it is clean. Walls, floors, and other bathroom fixtures should regularly be cleaned with a bathroom cleaner. Wash your shower curtain and window curtain as well.

Frequently Asked Questions

1.    Can a bathroom fan keep mold at bay?

Generally, a good bathroom fan will be a great solution to keep mold away, but I do recommend installing one properly. An exhaust fan inspection may aid in detecting correct temperature and moisture management. This is because a wrongly installed bathroom exhaust vent might be the source of your moisture issue. Moisture is one of the key factors mold need to flourish. Using a bathroom fan to remove excess moisture may help keep mold at bay.

2.    Can water seep through the grout in my shower?

Water can seep through grout in your shower. Broken or damaged grout is the most common cause of shower leaks. To avoid moisture under the tiles, check and fix grout as soon as you notice a problem. Otherwise, the wetness may undermine your wall or floor and destroy tile adhesive.

3.    Can I dry a shower wall and substrate?

You can dry your wall and substrate. But this is not something that will happen quickly. A shower wall is built to keep the water from the shower area away from the substrate and from behind the tiles. This means that it is difficult for water to reach those areas. The other way around, removing water from behind the tiles and the substrate is really hard as well. It will take a long time.

Good ventilation is a good start for drying. Using a dehumidifier with a fan can speed up the process somewhat. But it will still take a really long time. If you have a serious problem, I recommend removing some tiles or using another method to reach the substrate.