What causes hidden leaks in buildings

Hidden leaks are almost never accidental. Behind each one lies a specific cause, which has usually been at work long before the first patch appeared. Understanding the cause has practical value: it shows whether the problem is local, or will repeat somewhere else in a month.

Fatigue and the age of the material

Galvanised pipes from older construction corrode from the inside out. The bore narrows, the walls thin, and at some point a pinhole forms. The process is slow and uniform across the whole installation — which is why, in such buildings, one leak is often followed by a second nearby.

Poor installation

• Pressing without checking — a fitting not fully made up passes a drop at a time for months.
• Mechanical stress — a pipe built in under tension works against its own elasticity.
• No protective sleeve where a pipe passes through screed, leaving it to chafe against the concrete.
• Mixing incompatible materials, which accelerates corrosion at the joint.

Building movement

New construction settles. Joints move by millimetres, and that is enough to compromise a connection or the waterproofing. For the same reason, leaks in panel buildings often appear along the joints between elements.

Freezing

Water in a pipe on an unheated terrace, in a chamber or along an external wall freezes and expands. The crack forms in winter, but the leak shows in spring, when the system is refilled.

Pressure and water hammer

Stopping the flow abruptly by closing a tap creates a shock wave in the installation. Repeated thousands of times, it breaks connections and seals. Buildings with high mains pressure and no pressure-reducing valve suffer most often.

Compromised waterproofing

Here there is no fractured pipe — water from normal use passes where it should not. The cause is worn silicone, crumbling grout, a poorly executed detail around the trap, or waterproofing omitted under the shower tray.

Roots and external factors

External runs and drainage add factors that have nothing to do with the material: roots seeking moisture and entering through the smallest crack, ground settlement, loading from vehicles over a shallow pipe.

This is why diagnosis does not stop at “we found where it leaks”. The cause determines whether the repair will hold.

How the cause is established

With a combination of moisture measurement, thermography and — for drainage — a CCTV survey showing the internal condition of the pipe. The result goes into a report with specific recommendations for putting it right.

Get in touch for a free preliminary consultation.