A leak in the ceiling is stressful, and the stain is often nowhere near the actual problem. Here are the causes we find most often on Auckland tile roofs.
1. Cracked tiles
The most common cause. Tiles get more brittle with age and crack when people walk on them in the wrong place. A hairline crack can be enough to leak in wind-driven rain.
2. Failed ridge or hip mortar
The caps along the top of the roof sit on a bed of mortar. Over time it cracks and crumbles, gaps open up, and water gets in at the highest point of the roof. See rebedding vs repointing.
3. Blocked valleys
Valleys are the channels where two roof slopes meet. When leaves and moss build up, water backs up and runs sideways under the tiles.
4. Blocked gutters
When gutters overflow, water can back up into the soffit and the top of the walls. It can look like a roof leak from inside.
5. Slipped or lifted tiles
Wind can lift tiles that aren't secured, and failed fixings let tiles slide out of line, leaving a gap.
6. Around chimneys, vents and skylights
Anywhere something goes through the roof is a weak point. Flashings and seals age and lift.
7. Damage from other trades
Aerial, satellite, solar and painting crews walk on roofs all the time. If a leak started soon after someone was up there, cracked tiles are a likely cause.
How to narrow it down
- Only leaks in heavy rain or wind? Likely wind-driven rain getting under a cracked tile or ridge gap.
- Leaks every time it rains? Likely a bigger gap, a missing tile or a blocked valley.
- Stain near an outside wall? Check whether the gutter above is overflowing.
- Started after work on the roof? Likely cracked or disturbed tiles.
Please don't get on the roof yourself. Wet tiles are slippery, old tiles crack underfoot, and falls from roofs cause serious injuries. Use a bucket, move valuables, and take photos for us.
Why leaks keep coming back
Because the repair was done where the water showed up, not where it got in. Water can travel a long way across underlay and timber before it drips. We once traced a leak that had beaten several roofers over ten years and fixed it within an hour. Read about our leak detection.