How a tile roof really keeps water out
Concrete and clay tile roofs are everywhere in Tucson, and the tile itself is tough. But the tile isn't the main waterproofing. Underneath it is a layer of underlayment, and that membrane is what actually protects the house. Arizona home expert Rosie Romero writes that tile underlayment generally lasts about eight to 20 years, and that even one cracked tile can let monsoon water slip under the tile and damage it (source).
That's the key to understanding tile roof repair: a tile roof can look fine from the street while the layer underneath is worn out.
Common tile roof problems
Cracked and broken tiles
Tiles crack from people walking on them (including other trades servicing AC units or solar), falling branches, and age. Clay breaks more easily than concrete. A cracked tile lets water and sun reach the underlayment, which speeds up its wear.
Slipped or loose tiles
Tiles that slide down out of line leave gaps. It usually means failed fasteners or adhesive, or a batten problem underneath.
Worn-out underlayment
Heat and UV dry the underlayment out until it cracks and tears, especially where it's exposed at edges, valleys and around broken tiles. Leaks often show up after big monsoon storms.
Flashing and valleys
Valleys, roof-to-wall joints, chimneys, skylights and pipe penetrations are where water concentrates. Debris that builds up in valleys pushes water sideways under the tile.
Installation shortcuts
Romero also notes that tiles stretched beyond the recommended overlap let water in, and the only fix for that is to re-lay the roof.
How we repair tile roofs
Replacing individual tiles
For a few broken tiles, we lift the surrounding tiles carefully, check the underlayment below, and set matching replacement tiles. Older tile profiles and colors can be hard to find, so we look for the closest match. Where a perfect match isn't available, it's common practice to move original tiles from a less visible part of the roof to the front and put replacements where they won't be seen.
Spot underlayment repair
Where a single area has leaked, such as around a valley or a pipe, the tile comes off that section, damaged underlayment and flashing are replaced, and the tile goes back.
Full re-lay
When the underlayment has failed across the roof, the right fix is a re-lay. Tiles are lifted and stacked, new underlayment, battens and flashings go on, and the good tiles are reinstalled with broken ones replaced. It's usually far less than all-new tile, and the roof gets a fresh waterproofing layer for years to come. For how this compares with other options, see our roof replacement and roof replacement cost guides.
Deck repairs
If a long-running leak has softened the sheathing, it gets replaced while the roof is open. In the City of Tucson, replacing sheathing or decking needs a permit, according to the city's permit exemptions page. Same-type tile replacement without structural work is exempt, except in Historic Preservation Zones.
Looking after a tile roof
- Stay off it. Walking on tile breaks it. Rosie on the House recommends checking from the ground or a ladder and having a qualified roofer inspect yearly.
- Keep valleys and edges clear of leaves and debris, especially before monsoon.
- Watch who goes up. AC, solar and satellite technicians crack a lot of tiles. Check after any service visit.
- Fix cracked tiles quickly, before the sun and rain get to the underlayment.
Our monsoon home prep checklist covers what to look at each spring.
One licensed roofing crew
Roofing is one of the trades our own crew does in house, and so is stucco, which matters where tile meets walls and parapets. We look at the roof, explain whether you need a few tiles, a section, or a re-lay, and give you a written estimate. If water is already coming in, see our roof leak repair page. AZ Atlas Builder Group is a licensed general contractor, AZ ROC #344537.