The Hidden Truth About Your Shower Leak: A Case Study from Brisbane
We recently investigated a frustrating shower leak at a two-level brick veneer home in Rothwell, Queensland, that perfectly illustrates a common, yet often overlooked, problem in bathroom construction. The homeowner was experiencing water ingress and damage to the first-floor door jamb of their main bathroom, a tell-tale sign of a hidden issue.
Our specialist team arrived equipped with advanced tools, including a Flir E96 thermal imaging camera, TroTec moisture survey equipment, and conducted thorough water testing alongside visual inspections. Interestingly, our thermal imaging revealed no active leak upon arrival. The reason? The bathroom hadn't been used for a week. This immediately told us something crucial: the leak was directly correlated to shower usage.
The problem area was pinpointed to the shower recess, directly adjacent to the damaged door entry. While the shower passed most plumbing tests, the crucial flood test confirmed water egress. This is where the inherent problem was uncovered.
The Missing Barrier: A Critical Design Flaw
The most significant defect and compliance issue we found was the absence of a water stop at the door jamb. This seemingly small omission is a major culprit. Without a proper water stop, water has a free path to migrate from the shower recess directly into the surrounding structures, leading to the kind of damage seen in the door jamb.
Furthermore, a recent attempt at grout replacement had been made, but it proved ineffective. This led us to investigate the underlying cause, and we discovered a critical defect in the tiling method itself. In many bathrooms, floor tiles are laid first, followed by wall tiles the next day, with grouting as the final step. This common practice often means the wall tiles sit directly on top of the floor tiles. This creates a small, inherent cavity around the tile edge of the floor where the grout often doesn't fully penetrate or reach the end of the tile.
In such scenarios, a silicone seal is often the only barrier against water penetration. However, silicone, especially with heavy and prolonged use, often fails to adhere effectively or deteriorates over time. This leaves that small, unsealed cavity as a prime entry point for water, allowing it to seep through and cause damage like the water ingress observed at the Rothwell property.
The Solution: Addressing the Root Cause
To comprehensively resolve this pervasive problem, our recommendation for the Rothwell home, and similar situations, is to go beyond superficial fixes. The complete repair involves:
Removing the shower screen: This allows for clear access to all tiled surfaces.
Regrouting both the floor and walls of the shower recess with epoxy grout: Unlike traditional cementitious grout, epoxy grout is non-porous and highly resistant to water penetration. Crucially, it must be properly applied to ensure it fills and seals the inherent cavity created by the tile layering method.
This case highlights that many shower leaks aren't just about cracked grout or faulty seals, but can be rooted in fundamental construction practices that create vulnerabilities. Understanding these inherent problems is key to effective and lasting leak detection and repair. If you're experiencing a shower leak, it's vital to get a professional assessment to identify and address the true source of the problem.
Water leaking under the floor tiles at the door jamb following a flood test!
