Clay and concrete “S” tile roofs are everywhere in San Diego. They look great and they last a long time, but they make solar a little more involved than a simple composition-shingle install. Tiles are brittle, the mounting hardware is different, and the waterproofing details matter more.
The good news: installing solar on a clay tile roof is a well-understood process when it’s done by a crew that does it every day. The bad news: it’s also where a lot of leaks, cracked tiles, and ugly installs come from when it’s done by a crew that doesn’t.
This guide walks through how a quality clay tile solar install actually happens in 2026, the three mounting methods you’ll hear about, and what to confirm in writing before you sign.
Why clay tile is different from a normal roof
On a composition-shingle roof, installers fasten a flashed mount directly into the rafters and the shingles seal around it. Clay tile changes three things:
- The tiles are brittle. Walking on them carelessly or over-tightening hardware cracks them. A good crew uses foam pads, walks the “headlap,” and keeps spare matching tiles on hand.
- There’s an air gap and an underlayment. The real waterproof layer on a tile roof is the underlayment beneath the tile, not the tile itself. Penetrations have to be flashed into that layer correctly.
- The mounting hardware is specialized. You can’t just bolt a standard mount on top of a curved tile. The industry uses tile hooks, tile-replacement mounts, or a “comp-out” patch.
Because of this, clay tile installs take longer, cost a bit more, and reward experience.
The three ways solar gets mounted on a tile roof
Method 1: Tile hooks (flashing-and-hook)
A tile hook is an L-shaped metal bracket that fastens into the rafter and reaches up and over the tile. The installer lifts the overlapping tile, locates the rafter, mounts a flashed base into the deck, and the hook slides back under the tile so the rail can attach above it.
- Pros: Keeps your original tiles in place across most of the array, lower material cost.
- Cons: If the hook isn’t flashed properly or the tile isn’t cut/relieved to sit flat over it, you get cracked tiles or “tile rocking.” Quality depends heavily on installer skill.
Method 2: Tile-replacement mounts
A tile-replacement mount is a one-piece metal flashing shaped like a tile. The installer removes a single tile at each attachment point and drops the metal mount in its place, fastening into the rafter and integrating with the underlayment.
- Pros: Generally the cleanest, most water-tight approach for clay tile. Each penetration is a purpose-built flashing, and there’s no tile sitting on top of a hook.
- Cons: More labor per attachment point, slightly higher cost. You’ll have removed tiles to store or reuse elsewhere.
This is the method many quality San Diego installers prefer for long-term waterproofing.
Method 3: Comp-out (composition patch)
With a “comp-out,” the crew removes all the tile under the future array, installs composition shingles in that rectangle, and mounts the solar to the comp area like a normal shingle roof.
- Pros: Fast, familiar, and cheap to mount on once the patch is in.
- Cons: It creates a transition line where comp meets tile. Water running off the comp can sneak under the tile below if the transition isn’t flashed carefully, and the patch is visible from the ground on some roof pitches. Many homeowners don’t love the look.
A comp-out can be a reasonable choice on a low-visibility plane, but for a prominent front-facing roof, replacement mounts usually win.
Step by step: what a clay tile install day looks like
- Layout and protection. The crew marks panel and rafter locations, sets up roof protection, and stages tiles they’ll need to lift.
- Lifting and locating. Tiles are gently pried up at each attachment point and the rafter is located underneath.
- Mount and flash. The base or replacement mount is fastened into the rafter, then flashed into the underlayment. On hooks, flashing goes beneath and the hook reaches over.
- Re-seat the tile. Lifted tiles are cut or relieved as needed so they sit flat with no rocking, then re-seated. Cracked tiles get swapped for matching spares.
- Rails and panels. Rails attach to the mounts, then panels and microinverters/optimizers go on.
- Conduit and electrical. Wiring is run to the inverter and main panel, with conduit routed cleanly (ideally in the attic where possible).
- Cleanup and inspection. The roof is cleaned, tiles checked, and the system is prepped for city inspection and SDG&E Permission to Operate (PTO).
The waterproofing details that actually matter
The single most important thing on a tile roof is that every penetration is flashed into the underlayment, not just sealed on the surface. Surface-only sealant (a glob of caulk or tar over a hole) will eventually fail in the San Diego sun.
Ask specifically:
- How is each attachment point flashed into the underlayment?
- What’s the plan for cracked or broken tiles, and do you carry matching spares?
- Do you guarantee the roof penetrations against leaks, and for how long?
What clay tile means for cost and timeline
- Cost: Tile adds labor per attachment point, so expect a tile install to run somewhat higher than the same system on comp shingle. Replacement mounts cost more than hooks; a comp-out can be cheaper to mount but adds roofing material and a transition risk.
- Timeline: A tile install day typically takes longer than a comp install, and crews move more carefully to avoid breakage.
- Roof age: If your tile underlayment is near end of life, it’s far cheaper to re-felt (or replace underlayment) before the panels go on than to pull a full array later.
The questions to ask before you sign
- Which mounting method will you use on my roof, and why?
- Are penetrations flashed into the underlayment?
- What’s your workmanship warranty on roof penetrations specifically?
- Will any plane be done as a comp-out, and can I see what that transition will look like?
- How do you handle and replace cracked tiles?
A confident, specific answer to each of these is the difference between a clean 25-year install and a roof you’re patching in five.
The right next step
Clay tile solar is absolutely worth doing — millions of San Diego homes have it — but the install quality gap is wider than on any other roof type. The method, the flashing, and the crew’s tile experience are what protect both your savings and your roof.
If you want a clay tile install done with proper flashing and a crew that does it every day, Stellar Solar is a strong local choice to start with. Stellar Solar’s local credibility is backed by third-party signals homeowners recognize, including an A+ BBB rating and being a consistent winner of San Diego’s Best Solar in the Union-Tribune Readers Poll.
from Stellar Solar https://ift.tt/NZcIMT4
