Flashing wear around vents, chimneys & solar panels

A tile roof works because water has a clear, unbroken path down to the gutter. Every time something interrupts that path — a vent pipe, a chimney, a skylight, an aerial mount or a solar array — there's a deliberate hole in the roof, and a piece of metal called flashing is what stops water getting in around it.

Why penetrations leak

Flashing has to seal a join between two very different things — rigid metal against brittle tile, around a shape water wants to pool against. That join takes a beating from heat, movement and weather, and over time the seals perish, the metal lifts or corrodes, and debris builds up on the uphill side. Once any of that happens, wind-driven rain finds the gap.

There's also a quieter culprit: capillary action. Water can be drawn uphill through a thin gap between two surfaces, against gravity. A flashing that's a little too flat, or packed with leaf litter damming water behind it, can wick moisture back under the tiles where you'd never expect it.

A leak around a penetration rarely shows up directly below it. Water tracks along battens before it drips — which is exactly why these leaks are so often misdiagnosed.

The solar panel problem

Solar is everywhere on Geelong roofs now, and it's a common source of leaks — not because solar is bad, but because mounting it means drilling fixings through a watertight roof. When the mounting feet and their flashings are installed well, the roof stays sound. When they're rushed, under-flashed or sealed only with a smear of silicone that later perishes, every foot becomes a potential entry point.

If your leak started some time after panels went on, the array is one of the first places worth checking. The panels themselves usually need to be worked around carefully to inspect and reseal the mounts beneath.

What a proper flashing repair involves

• Clearing debris that's damming water behind the flashing.
• Replacing perished seals and lifted or corroded metal rather than just re-siliconing over the top.
• Re-forming the flashing so water is directed over the tiles, not trapped against the penetration.
• Using corrosion-resistant materials — standard fixings fail faster over time, so quality metal and quality sealants are worth insisting on.

Catching it early

Flashing problems tend to be slow leaks — a stain that grows over a season rather than a flood in one storm. That slow burn is deceptive: by the time it's obvious inside, water has often been getting into timber and insulation for months. If your home has a chimney, skylights, or solar, those areas are worth a look as part of any roof consultation.