Why your tile roof leaks when the tiles look perfect
By A&J Roofing Inc. ·
A tile roof is a bit like a very good umbrella with a paper bag stapled inside it. The umbrella gets the credit, the bag does the work, and nobody looks at the bag until it is soggy. If your tile roof leaks and the tiles look fine, the bag is your problem. The short answer: the underlayment beneath the tile has worn out.
Is a tile roof waterproof?
No. Clay and concrete tile shed most of the water, but not all of it. Wind-driven rain gets under the edges, water wicks through the laps, and some always reaches the layer below. That is by design. The underlayment underneath is the actual waterproof layer, and the tile protects it from sun and weather.
Which is why "my tile roof should last 50 years" is half true. The tile might. The underlayment usually does not, and it was the part keeping your ceiling dry all along. (The tile has been taking credit for decades. Classic tile.)
How does tile roof underlayment fail?
Older tile roofs in Southern California commonly used felt underlayment. Heat cycles dry it out, it turns brittle, and it starts to crack along the battens and at the laps. Once it splits, the water that always gets under the tile now gets to the wood deck.
The first sign is often a stain after the first big storm of the season, or a leak in a spot that never leaked before. On many homes built from the 1970s to the 1990s, that original layer is now somewhere between tired and retired.
- Ceiling stains that appear after heavy rain, not light rain
- Leaks near valleys, chimneys, skylights or walls
- Brittle, black flakes in the gutters below the tile
- A roof installed 20 to 30 years ago with no underlayment work since
What is a tile lift-and-relay?
A lift-and-relay is the usual fix. The tile comes off, the old underlayment and any rotten battens are removed, the deck is checked, new underlayment goes down, and the same tile goes back on. Broken tiles are swapped for matching ones.
From the street, the house looks exactly the same. That is handy if your HOA has opinions about tile color, and most of them have several.
Can one leak be repaired without redoing the whole roof?
Yes, if the underlayment is still sound elsewhere. We lift tile in the problem area, repair the underlayment and flashing, and relay. If the underlayment is brittle everywhere, patching one spot tends to move the leak a few feet over, and you end up paying for the same visit twice. A good roofer tells you which situation you are in before taking your money.
What should I do if my tile roof is leaking?
Put a bucket under it, take a photo of the stain, and note when it leaked and how hard it was raining. Do not walk on the tile yourself: tile cracks under a boot, and a cracked tile is a leak with a delayed start date.
Then call A&J Roofing on (714) 925-5056 or send the form. We trace the leak to its source and tell you straight whether it needs a repair or a relay. The umbrella will be fine. It is the bag we need to talk about.