Shower Leaking Behind the Wall: Discover Causes and Fixes

A leaking shower concealed within the wall typically results from water infiltrating through damaged grout and silicone, allowing it to travel behind the tiles. The most frequent sites for these leaks include the junction between wall tiles and the floor, internal corners, and connections within tiled recesses. Fortunately, these problems can often be rectified through regrouting and resealing, which usually avoids the need to remove any tiles. in rare instances, leaks may stem from a pipe hidden within the wall, requiring the expertise of a plumber, or from a compromised waterproofing membrane situated behind the tiles, necessitating tile removal.

This guide aims to assist you in pinpointing the source of the leak and determining the appropriate professional to tackle each specific issue.

Identifying Common Leak Sources Behind Shower Walls

The visible damp patch may not be situated directly at the leak’s source. Water can migrate behind the tiles after seeping through a cracked grout line or a lifting silicone bead, meaning that the joint requiring inspection may not be the closest one to the stain.

The following joints are frequently responsible for allowing water to penetrate behind a shower wall:

• The junction between the wall and floor: This area experiences significant water exposure and movement within the building, making it the most common failure point due to frequent cleaning.
• Internal corners: As buildings settle, corner joints can shift, often leading to cracked silicone where two tiled walls converge.
• Surrounding taps, mixers, and shower heads: A failed seal around these fittings permits water to seep behind and into the wall.
• Where wall tiles meet the shower screen: The joints around the screen can flex during use, potentially causing the silicone to gradually detach.
• Grout lines on the wall and in tiled recesses: Grout is porous, and once it cracks, crumbles, or softens, water can easily infiltrate.

What Actions Can You Take to Identify a Leak Behind Your Shower Wall?

Leaks behind the wall are generally not visible from inside the shower, making it essential to inspect the surrounding room and the area on the opposite side. Signs to look for include bubbling or peeling paint, swollen skirting boards or door frames, persistent musty odours, or stains on the ceiling below. For a comprehensive overview of warning signs, consult our article on identifying shower leaks and the necessary follow-up actions.

Once you locate the damp area, its position and the timing of its emergence can often offer clues about the underlying cause:

• Damp appearing at skirting level just outside the shower: This often indicates a failed seal at the junction between the wall and floor.
• Damp that appears after someone showers and dries out between uses: This may suggest issues with grout or silicone, especially if the corners seem cracked, dark, or crumbling. A leak at the waste pipe may exhibit similar behaviour, as it usually only becomes noticeable when water drains.
• A damp patch that continues to expand when the shower has not been used for several days: This indicates a potential water pipe leak within the wall, which should be examined by a licensed plumber.
• Damp that keeps spreading even after proper regrouting and resealing, assuming a pipe leak has been ruled out: This typically signifies a failure of the membrane behind the tiles.

How to Perform a Simple Shower Leak Test Before Contacting a Professional

There is no need to cut into the wall to diagnose a leak. These assessments can be performed at no cost over a few days.

1. Document the damp patch with a photograph for future reference.
2. If possible, avoid using the shower for several days and take daily photographs of the damp area. If the dampness increases while the shower remains off, this indicates a potential pipe leak, and you should consult a plumber before proceeding with any shower repairs.
3. If the damp mark remains constant or dries out while the shower is off, thoroughly inspect the previously mentioned joints. Cracked, missing, or crumbling grout, along with silicone that appears blackened, lifted, or pulling away, will help identify the source of the leak. A mark that only appears after using the shower may still be due to grout, silicone, or the waste pipe.
4. Share your photos of the damp patch and the shower with us for further insights.

If you are still unsure whether the issue lies with the grout or plumbing, we can recommend a trusted plumber to conduct a dye or pressure test, which can assist in distinguishing between the two issues, or we can arrange to inspect the shower ourselves.

What Should You Do If You Notice Leaks Into the Ceiling or Below the Shower?

In upstairs bathrooms, the initial indication of a leak often manifests as stains, bubbling paint, or sagging ceilings in the room below. Similar to damp walls, a ceiling stain typically does not appear directly beneath the leaking joint and may be fed by a grout line several metres away.

The same testing procedures apply for ceiling leaks, so utilise the dry shower test mentioned earlier as a first step. If water is penetrating through the shower floor, consult our article on regrouting and resealing shower floors for potential solutions.

If you notice staining near a downlight, light fixture, or power point, cease using the shower immediately and contact a licensed electrician. Repairs to the shower can be arranged once the electrical issues have been resolved.

Choosing the Right Professional for Repairing a Leak Behind the Shower Wall

Addressing Failed Grout and Silicone: The Importance of Regrouting and Resealing

Most leaking shower walls we encounter are attributed to failed grout and silicone. Our comprehensive shower sealing process includes the removal of all wall and floor grout, regrouting with Ardex epoxy grout, resealing internal corners and junctions with fresh silicone, and sealing tap flanges. The existing tiles remain intact throughout this process. For a detailed description of this method, refer to our article on stopping a leaking shower without removing tiles, as well as our leaking shower repairs page.

Applying a new bead of silicone over an old one does not resolve the underlying issue. Silicone cannot properly adhere to old silicone, soap residue, or mould, which leads to future lifting and ongoing leakage. For more information on distinguishing a genuine shower reseal from a mere cover-up, see our related article.

Effective sealing also protects the wall behind it. When grout and silicone fail, water accumulates against the membrane, which can deteriorate at the corners and junctions. This is a primary reason to address leaks promptly. More details on the consequences of neglecting a leak can be found in our article on why you should never ignore a leaking shower.

If There’s a Leaking Pipe, Drain, or Tap: Seek a Plumber’s Assistance

If the leak originates from the pipes, drain, or taps, a licensed plumber must address the issue first. We collaborate with plumbers for these repairs, and the shower can be resealed once the plumbing concerns have been resolved.

When the Membrane Behind the Tiles Has Failed: Engage a Licensed Waterproofer and Tiler

Typically, a waterproof membrane is installed behind the tiles to capture any water that penetrates the surface. If this membrane has failed, it must be replaced by lifting the tiles, a task designated for a licensed waterproofer and tiler. Andreas’s licence covers waterproofing, as well as bath and shower resealing, enabling us to recognise the signs of a failed membrane. We will inform you of any costs before proceeding with a reseal.

If There’s a Leaking Shower Screen: Consult a Glazier

If water leaks from the silicone at the junction of the screen and tiles, replacing that silicone can often resolve minor leaks. If the screen frame itself is leaking, corroded, or improperly installed, it typically requires the expertise of a glazier or shower screen specialist. We can facilitate the removal of the screen as part of a reseal and coordinate its replacement with a glazier.

How to Tackle Mould on Shower Grout Near a Leak

Persistent mould on grout and silicone often correlates with a leak behind the wall. While bleach and mould sprays can clean the surface, the mould resides within the grout, nourished by trapped water, leading to its recurrence. We remove the affected grout and replace it with epoxy grout, which does not absorb water like cement grout. For a more detailed comparison, see our article on epoxy grout versus cement grout.

Managing Leaks Behind Shower Walls in Rental Properties and Homes for Sale

If you are renting and notice dampness on the wall behind the shower, inform your property manager without delay. Addressing a small leak at the grout or silicone is significantly easier before water has the chance to spread over time. For landlords and property managers, the period between tenants is an ideal time to regrout, reseal, and deep clean the shower while the bathroom is unoccupied.

For real estate agents preparing a home for sale, regrouting, resealing, and deep cleaning the tiles and grout greatly enhances the bathroom’s appeal. Since the old grout and silicone are replaced, the shower will pass inspection by potential buyers’ building inspectors, provided that the leak originated from the grout and silicone. More information can be found on our page specifically for real estate agents and property managers.

Common Queries Regarding Shower Leaks Behind the Wall

Is It Feasible to Repair a Leak Behind the Shower Wall Without Removing Tiles?

Yes, if the water is entering through the grout and silicone, which is the most common cause. We can perform regrouting and resealing without removing the tiles. If the membrane behind the tiles has failed, however, tile removal is necessary.

Do Plumbers Address Leaks Behind Shower Walls?

A plumber addresses leaks from pipes, drains, or taps located within the wall. If water seeps through the grout and silicone, the solution is regrouting and resealing instead.

How Long Does It Usually Take to Repair a Shower That Is Leaking Behind the Wall?

A complete shower seal typically takes around 4 to 5 hours on site, after which the shower can be used again after 24 hours, once the epoxy grout and silicone have fully cured.

What Warranty Is Provided with the Repair?

Our regrout and reseal services come with a 10-year Ardex product warranty and a 7-year workmanship warranty. The warranty details will be included in your quote after we assess the shower to ensure proper sealing.

How to Request a Free Quote for a Shower Leak Behind the Wall

If you have observed dampness on the wall behind your shower, a stain on the ceiling below, or if the grout and silicone have discoloured, please email photos of the floor, wall, and entire shower, along with the damp patch, to sales@leakingshowerssealed.com.au. We will respond within 24 hours. Alternatively, you can call us at 1300 815 512 or contact us to arrange a free quote. Provide details about the damp location and its appearance, and we will advise whether a shower reseal and regrout are suitable for your situation.

Leaking Showers Sealed has specialised in regrouting and resealing showers in Sydney since 2016. Andreas, the business owner, holds NSW contractor licence 89111C, which can be verified on the NSW Fair Trading public register. We are Ardex Academy accredited and have accumulated over 300 Google reviews across our three locations.