Tile Sheds Water, Underlayment Stops It: Where Tile Roof Leaks Really Begin
When a tile roof leaks, the cause usually sits in the drainage beneath the tile rather than the tile itself.
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The most useful thing to understand about a tile roof is that the tile is not what keeps water out of the house. Homeowners find this counterintuitive, and it explains why a roof can leak steadily while every tile on it looks sound from the driveway.
Tile sheds the bulk of the water and protects what sits beneath it. The underlayment is the actual waterproofing layer. Water that gets past or around the tile, which it routinely does, is supposed to land on the underlayment and drain away. When a tile roof leaks, the question is almost always what happened to that drainage path.
In this guide
How tile is set, and why it changes the drainage
Tile can be installed two ways and the method affects how water moves underneath it.
Direct to deck means the tile is fastened down onto the underlayment over the sheathing, with no intermediate framing. Water reaching the underlayment runs down the slope across its surface and out at the eave.
Battens are horizontal strips the tile is hung on, which lifts the tile off the underlayment and creates an air space beneath. Battens come in a regular form and an arched or counter form, and the distinction matters for drainage. A plain horizontal batten laid flat across the slope can act as a small dam, holding water against its upslope side rather than letting it pass. Arched or raised battens are shaped so water can run underneath rather than being stopped by them.
That is the first place to look on a leaking tile roof. If water is reaching the underlayment correctly but then sitting against an obstruction rather than draining out, the leak has nothing to do with the tile at all.
Bird stop, weep holes, and the difference between curved and flat tile
This is one of the clearest distinctions between tile profiles and it has direct consequences for drainage at the eave.
Curved tile, the barrel profiles including capri and Capistrano, leaves an open space at the eave because of the shape of the tile. That opening was closed with a component called bird stop, which blocks birds and rodents from nesting up under the tile. Correctly specified bird stop includes weep holes, which are deliberate openings that let water reaching the underlayment drain out at the eave instead of being trapped behind the bird stop.
Flat tile does not use bird stop, because the profile does not leave the same opening to close. The drainage detail at the eave is handled differently as a result.
Where this becomes a leak is when bird stop is present without functioning weep holes, or when the weep holes have been blocked. Debris, mortar from the original installation, or later sealing work can all close them off. Once they are closed, water that correctly reached the underlayment has nowhere to exit, and it backs up along the eave until it finds a way into the structure.
Pointing and mortar at hips and ridges
The other common intrusion point on a tile roof is at the hips and the ridge, and the cause is mortar rather than tile.
Hip and ridge tiles are bedded and the joints between them are finished with mortar, which is the work referred to as pointing. That mortar is exposed at the highest and most weather-beaten lines on the roof, and it does not last as long as the tile it sits between.
Over years it cracks, crumbles and breaks away in sections. Once the pointing has broken apart, the hip and ridge lines are open. Water driven by wind, which this region produces in volume during storm season, enters directly through those openings at the top of the roof and runs down inside the assembly.
This is worth inspecting specifically because broken pointing is visible and identifiable, and because it is repairable without disturbing the field tile. A tile roof with sound tile and failed pointing at the hips and ridges is a repair situation rather than a replacement one.
Why the leak shows up far from the cause
Water that gets past the drainage path on a tile roof travels before it appears inside, which makes interior evidence unreliable as a locator.
It moves across the underlayment, along the deck, and frequently along framing, until it reaches a seam, a fastener or a joint it can pass through. The resulting ceiling stain can be a considerable distance from the failed detail. This is the main reason tile roof leaks get repaired more than once without being resolved, because each repair addresses the exit point rather than the entry.
Diagnosis works from the roof and from the drainage logic rather than from the stain. Where does water reach the underlayment, where is it meant to exit, and what is stopping it. Answering those three questions locates the problem far more reliably than working upward from the ceiling.
About Revildor
Revildor is a licensed Florida roofing contractor operating under licences CCC1328368 and CGC1508771. We are a CertainTeed ShingleMaster Pro contractor, a BBB Accredited business with an A plus rating, and a member of the Florida Roofing and Sheet Metal Contractors Association. Our ShingleMaster Pro credential also makes qualifying installations eligible for CertainTeed SureStart PLUS extended warranty coverage, though eligibility depends on the system specified.
We work across tile, shingle, metal and low slope systems, and tile diagnosis in particular is approached through the drainage path rather than by inferring a location from interior damage. Reach our team at (321) 332-3392.
Tile roof repair in Orlando, FL
Orlando has a substantial stock of tile roofs across its older and higher end neighbourhoods, and many are far enough along that the pointing at hips and ridges is at or past the end of its service life even where the tile itself has decades remaining.
The storm pattern here compounds it. Wind driven rain during the summer season reaches openings that ordinary vertical rainfall never would, which is why a tile roof in Orlando can perform perfectly for years and then leak during one storm without anything having broken that day.
More detail on the systems we work with is on our tile roofing page.
Have a tile roof leak looked at properly
If a tile roof has leaked more than once in the same general area, the likelihood is that the entry point has not been found yet. A diagnosis that follows the drainage path will locate it.
Get in touch to arrange an assessment, or read about our roof repair work.
Frequently Asked Questions
If my tiles look fine, why is my roof leaking?
Because tile is not the waterproofing layer. Tile sheds the bulk of the water and protects what sits beneath, while the underlayment is what actually keeps water out. Water routinely gets past or around tile by design, lands on the underlayment and drains away. A leak usually means something has interrupted that drainage path rather than that a tile has failed.
What is bird stop and why does it matter?
Bird stop closes the opening left at the eave by curved tile profiles such as capri and Capistrano, keeping birds and rodents from nesting beneath the tile. Correctly specified bird stop includes weep holes so water reaching the underlayment can drain out at the eave. Flat tile does not use bird stop, since the profile does not leave the same opening.
Can blocked weep holes cause a tile roof leak?
Yes, and it is a common cause. Weep holes let water that reached the underlayment exit at the eave. Debris, mortar from the original installation, or later sealing work can close them. Once blocked, water that drained correctly down the underlayment has no exit and backs up along the eave until it finds a path into the structure.
What is pointing on a tile roof?
Pointing is the mortar finishing the joints between hip and ridge tiles. It sits on the most exposed lines of the roof and has a shorter service life than the tile around it. Over years it cracks and breaks away, leaving those lines open. Wind driven rain then enters directly at the top of the roof and runs down inside the assembly.
Does broken pointing mean I need a new tile roof?
Not usually. Failed pointing at hips and ridges is repairable without disturbing the field tile, so a roof with sound tile and deteriorated pointing is generally a repair rather than a replacement. The assessment worth making is whether the tile, the underlayment and the drainage details are also at end of life, which is a separate question.
Why does my tile roof leak show up far from the damage?
Water passing the drainage path travels across the underlayment, along the deck and often along framing before reaching a seam or fastener it can pass through. The ceiling stain marks the exit, not the entry. This is why tile leaks are frequently repaired more than once without resolving, since each attempt targets where water appeared rather than where it entered.
Find where the water gets in
Our team traces tile roof leaks from the drainage path down, so the repair targets the entry point and not the stain. Call (321) 332-3392 or contact us online.
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