Tile roofs are common in Arizona, and the tiles themselves can last for decades. What actually keeps water out is the underlayment beneath them, which wears out much sooner in our heat. Arizona roofers commonly estimate traditional felt underlayment lasts somewhere around 15 to 25 years. If a tile roof is about twenty years old and the underlayment has never been replaced, have a licensed roofer look at it, whether you're buying, selling or staying put.
If you own or are buying a home in the Phoenix area, there's a good chance it has a tile roof. Tile looks great and stands up well to the sun. But here's the part most people don't know: the tile isn't what keeps the rain out. The layer underneath it, called the underlayment, does that job, and in Arizona it usually wears out long before the tile does.
Why the underlayment matters
Roof tiles shed most of the water and protect what's under them from the sun. The underlayment is the waterproof layer between the tile and the roof deck. When it gets old, it dries out, cracks and tears, and water that slips past the tile can reach the wood and the ceiling below. That's why a tile roof can look perfect from the street and still leak during a monsoon storm.
How long it lasts
There isn't one number, because it depends on the material, the installation, ventilation and how much sun the roof gets. Arizona roofers commonly put traditional felt underlayment somewhere around 15 to 25 years in our climate. For example, one Valley roofing company says felt typically lasts about 15 to 20 years in Arizona, while Rosie on the House has reported an even wider range. The tile itself can last much longer.
The practical takeaway: if a tile roof is around twenty years old and the underlayment has never been replaced, it deserves a professional look.
Signs it may be time
| What you might see | What it can mean |
|---|---|
| Water stains on ceilings, especially after storms | Water is getting past the tile and underlayment |
| Cracked, slipped or missing tiles | Openings for water and sun to reach the underlayment |
| Granules or bits of felt in gutters | The underlayment may be breaking down |
| Roof age around twenty years with no records | Worth an inspection even without a leak |
Many problems show up first in valleys, where two roof slopes meet, and around chimneys, vents and skylights.
Heat and ventilation
Arizona attics get extremely hot in summer, and that heat bakes the underlayment from below while the sun bakes the roof from above. Good attic ventilation helps a roof last longer and can help with cooling costs too. When a roofer looks at your roof, ask whether the attic is vented properly, and if you replace the underlayment, ask whether the ventilation will be checked or improved at the same time. Underlayment manufacturers often have their own ventilation requirements for their warranties, so it's worth getting right.
How a roofer checks it
A home inspector will note the condition of the tile and any visible issues, but they usually can't see much of the underlayment without lifting tiles. A licensed roofer can lift a few tiles in key spots, like the valleys and the lowest edges, and tell you what condition the underlayment is in. If you're buying a home with an older tile roof, I often suggest adding a roofer's evaluation during your inspection period.
What replacement involves
Replacing underlayment doesn't usually mean buying new tile. The roofer removes the tiles, stacks them, replaces the underlayment and any damaged wood, then puts the tiles back. Some tiles break in the process, so a quote should say how many replacement tiles are included. Get more than one written quote and check each roofer's license with the Arizona Registrar of Contractors.
Ask about the underlayment product too. Rosie on the House has written about a regional study raising concerns with some synthetic underlayments under tile in our desert heat, and recommends asking roofers about a product's record in Arizona. You can read that in Rosie's guide to comparing roofing quotes.
If you're buying
The roof is one of the most expensive systems in a home. Ask the seller how old it is, whether the underlayment has been replaced and whether there are receipts or a warranty. If the roofer says the underlayment is near the end of its life, that's a fair item for the BINSR, whether you ask for a repair, a credit or a price change. More in How to negotiate repairs after an inspection.
If you're selling
An older tile roof is one of the most common items on a buyer's repair list. Getting a roofer's opinion before you list lets you decide on your own terms whether to replace the underlayment, offer a credit or price for it. Any past leaks belong on your Seller's Property Disclosure Statement. See Preparing your Arizona home for sale.
If you're staying
Have the roof checked before monsoon season, keep valleys and gutters clear and replace broken tiles promptly. If you have solar panels on the roof, plan underlayment work before the panels need to come off for any other reason, since removing and reinstalling them adds cost.
The bottom line
On a tile roof, the underlayment is the part that protects the house. Know its age, have it checked when it's getting there, and plan for it before a storm makes the decision for you.
Send me a message if you'd like help reading a roof report or finding a roofer to take a look.
Questions, answered.
Does a tile roof need to be replaced when the underlayment wears out?
Usually not. The roofer removes the tiles, replaces the underlayment and any damaged wood, then puts the tiles back, replacing any that break.
How long does tile roof underlayment last in Arizona?
It depends on the material and installation. Arizona roofers commonly estimate traditional felt underlayment lasts somewhere around 15 to 25 years in our climate.
Can a home inspector check the underlayment?
Inspectors note what they can see, but usually can't see much of the underlayment. A licensed roofer can lift tiles in key spots and tell you its condition.
Is underlayment a fair item to negotiate when buying?
It can be. If a roofer says it's near the end of its life, you can ask for a repair, a credit or a price change on the BINSR.
How do I check a roofer's license?
Look up the contractor on the Arizona Registrar of Contractors website before you hire them.
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