7 Reasons Your Roof Leaks When It Rains in Perth | Perth Premium Roofing
Here's the frustrating thing about roof leaks: the stain on your ceiling is almost never directly under the hole. Water gets in high, runs along tile battens, rafters and the back of your plasterboard, and drops out somewhere else entirely. That's why chasing the stain rarely fixes the leak — you have to find the source.
On the tile roofs of Perth's south-east, the source is nearly always one of these seven.
1. Cracked, chipped or slipped tiles
The most common cause of all. A tile cracked by age, a falling branch or someone walking on the roof lets water straight through — and a slipped tile leaves an open gap. One broken tile is a cheap fix; the trick is finding every broken tile, because storms rarely stop at one.
The fix: broken tiles replaced with colour-matched stock and re-seated properly.
2. Failed ridge capping pointing
The mortar sealing your ridge caps cracks and crumbles with age, and on homes built before the 90s around Thornlie and Gosnells it's usually well past its use-by date. Rain gets in along the very top of the roof and shows up as stains high on ceilings.
The fix: repointing — old pointing raked out, ridges resealed with flexible compound.
3. Rusted valley irons
Valleys are the metal channels where two roof sections meet, and they carry more water than any other part of your roof. The original galvanised irons on older homes rust out under decades of leaf litter — and once there's a hole, every downpour pours through it.
The fix: valley replacement — tiles lifted, new corrosion-resistant iron fitted, tiles re-laid.
4. Lifted or corroded flashing
Flashing is the metalwork sealing every junction — where the roof meets walls, chimneys, skylights and pipes. When it lifts in the wind, cracks, or rusts, water finds the gap within a single winter. Flashing leaks love to masquerade as "mystery" leaks because the entry point looks so small.
The fix: failed flashings re-dressed, resealed or replaced with new metal.
5. Blocked gutters backing water under the tiles
When gutters are full of leaves, heavy rain has nowhere to go — so it rises, backs up under the bottom row of tiles and pours into the eaves. It looks exactly like a roof leak, but the roof itself is fine. This one peaks every winter.
The fix: a proper gutter clean, ideally before the rains arrive — the cheapest "leak repair" on this list.
6. Overflowing or broken downpipes
A blocked or rusted-through downpipe forces the whole gutter run to overflow at its lowest point — often against a wall, where water finds its way inside and stains at ceiling-wall corners. If your "leak" is always in the same corner during heavy rain, look at the downpipe outside it.
The fix: downpipes cleared, repaired or replaced so water actually drains away.
7. Storm-shifted tiles
Perth's winter fronts and the storms that roll off the Darling Scarp can lift and shift tiles without breaking them — leaving gaps you'll never spot from the ground. If a leak appeared right after a big blow, this is the likely culprit.
The fix: a post-storm roof check, shifted tiles re-seated, anything cracked replaced.
While you're waiting for help
Don't get on the roof — wet tiles are dangerously slippery, and more people are hurt falling off roofs than by the leaks themselves. Put a bucket under the drip, move anything valuable, and if water is pooling and bulging in the plasterboard, a small controlled hole in the centre of the bulge lets it drain into a bucket instead of collapsing the ceiling.
Leak that won't quit?
We trace leaks to their true source and fix them there — with photos to prove it. Free quotes across Thornlie, Gosnells, Canning Vale and all of Perth's south-east. Call 0493616136.
