Water ingress is rarely as straightforward as it appears.
A resident might report water appearing around a window, across a ceiling or down an internal wall. It’s natural to assume the source must be somewhere nearby.
Often, it isn’t.
Water can enter a facade several metres away and travel through cavities, along framing or behind internal finishes before it finally becomes visible. That’s why water ingress investigations can be difficult – and why seemingly straightforward handyman repairs don’t always solve the problem.
For strata managers, this becomes particularly frustrating when the same apartment leaks again after repairs, or similar issues start appearing elsewhere in the building.
Over years of investigating facade defects, we’ve found that the culprit often isn’t a single failed product. It’s the point where two building systems meet.
Here are five interfaces we regularly look at when investigating water ingress.
1. The window might not actually be the problem
Windows tend to get blamed quickly, which is understandable. If water appears beside a window, the window seems like the obvious place to start.
But a window sits within a much larger facade system. The sill needs to drain correctly, jambs need to integrate with adjacent construction and water needs a pathway back to the exterior.
A small weakness at any of these junctions can allow moisture behind the facade, while the window itself may be performing exactly as intended.
2. Flashings only work if the water has somewhere to go
Flashings have a fairly simple job: collect water and direct it safely out of the building.
In apparently compliant installations, the problems usually occur at the ends and interfaces.
A flashing that stops short, doesn’t integrate with adjacent waterproofing or lacks a continuous drainage path can allow water to bypass the very system designed to manage it.
On drawings, these can look like insignificant details. In an existing building, they can become the source of years of recurring leaks.
3. A facade is only as strong as its connections
Look at almost any apartment building and you’ll see multiple materials and systems: glazing, concrete, masonry, cladding, balconies, roofs, balustrades and waterproofing.
None of them operate independently.
Where one finishes and another begins, somebody has to work out exactly how that junction will manage water.
These transitions are some of the most interesting areas to investigate because the individual components can all be perfectly sound while the connection between them is not.
4. A building that looks still is constantly moving
Facades expand and contract with temperature. Concrete shrinks. Steel moves. Wind creates deflection.
Movement joints exist to accommodate those changes, but they don’t last forever.
As joints age, sealants harden, adhesion weakens and small openings can develop. What begins as normal building movement can eventually create a new pathway for water.
For older strata buildings especially, this makes movement joints an important part of ongoing facade maintenance rather than something installed once and forgotten.
5. Sealant can hide a bigger problem
When a leak appears, adding or replacing sealant is understandably tempting. It’s relatively quick, visible and sometimes exactly what’s required.
But sealant isn’t a complete waterproofing strategy.
A well-performing facade uses multiple layers of protection – drainage, flashing, overlaps, pressure management and properly detailed interfaces all play a role.
If the same location has been resealed several times and continues to leak, the history of those repairs is useful information in itself. It may be telling you to look somewhere else.
One leak can tell you something about the whole building…
This is where water ingress investigations become particularly useful for strata.
A leak in one apartment might be an isolated defect but when the same window detail, balcony junction or facade transition is repeated hundreds of times across a building, an individual failure can also be an early indication of a more widespread issue.
That doesn’t automatically mean a major remediation programme is required. It does mean there may be value in understanding the pattern before continuing with isolated repairs.
The aim isn’t simply to find where the building is wet. It’s to understand how the water got there.
Once you understand the pathway, you’re in a much better position to determine whether you’re dealing with a one-off maintenance issue, an ageing component or a detail that’s likely to keep causing problems elsewhere.
With water ingress, the visible leak is often just the end of the story. The useful information is everything that happened before it got there.
Look beyond the leak…
Water appearing inside a building tells you there’s a problem.
Understanding how it got there and whether the same vulnerability exists elsewhere is what leads to better decisions about what happens next.
That’s where the right engineering advice matters. A good engineering consultant won’t simply identify where water is appearing or recommend another repair. They’ll look at the building more broadly, understand how its different systems interact and help determine whether you’re dealing with an isolated defect, an ageing component or something more systemic.
The goal isn’t simply to stop the leak. It’s to understand the building well enough to make the right decision about it.
