GAX Roofing crew working on a concrete tile roof with solar panels in Upland, aerial view

Homeowner Guide

Roof and Solar
Planning Guide

Solar panels sit on top of your roof, and the roof under them is the hardest part to get to later. Here is how to get the order right, and who is responsible for what, before either contract is signed.

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The Short Answer

Roof first, then solar. The area under an array is the hardest part of a roof to inspect or repair later, because the panels have to come off before anyone can work on it. Have a licensed roofer look at the roof before you sign the solar contract, decide what the roof needs, and get in writing who is responsible for the panels, the mounts, the holes in the roof and any leak.

Get these in writing

A licensed roofer's look at the roof before the solar contract
Who removes and reinstalls the panels, and their license
Who owns the system, and what your solar warranty or lease requires
Who flashes each mount when the panels go back
Who warrants the roof, the mounts and the penetrations
The underlayment under the array, by name

Stop and ask if

The solar contract is signed before anyone looked at the roof
Nobody can tell you who takes the panels off for a future roof job
Mounts go on with sealant and no flashing
There's cracked tile around the array after the install and nobody owns it
You haven't read what your lease or PPA says about removing the panels

Step 1

Check the Roof Before You Sign for Solar

Why the order matters

Panels, rails and conduit cover the part of the roof that's hardest to reach later. If the roof under them needs work, the panels have to come off first, and that means another crew, another schedule and another bill.

Who should look

A licensed roofer, not only the solar salesperson. Roofers in California hold a C-39 license; check it yourself on the CSLB license lookup.

What they should check

The roof covering, the underlayment where it can be seen, flashing, valleys and vents in the area where the array will sit, the attic under it, and on tile, whether the tile can be lifted and reused.

At GAXOur rule of thumb: if your roof has less than 10 good years left and you're considering solar, do the roof first. If it can wait, we'll tell you. If it can't, we'll explain why.

Solar array and conduit runs on a concrete tile roof in San Dimas before repair work begins — San Dimas: panels up and conduit running across the tile. Everything under it is out of reach until it all comes off.

Step 2

Decide What the Roof Needs First

A sound roof with a small problem

A repair, done and documented before the array goes on.

A worn area where the array will sit

Under panels, the fix should cover at least the whole section, not two tiles, because you can't warranty work you can't fully see.

Good tile, tired underlayment

A tile lift and relay: the tile comes up, new underlayment goes down, and the same tile goes back on.

A roof that's done

A replacement before the panels, so the array goes on a new roof.

At GAXUnder panels we do a full tile lift and relay, a tile replacement, or at minimum a repair across the whole facet.

Tile removed and old underlayment stripped to the deck under a solar array on a San Dimas roof — San Dimas: tile off and the old underlayment out, where the array sits.

Self-adhered underlayment going down on a Rancho Cucamonga solar roof repair before the tile goes back — Rancho Cucamonga: new self-adhered underlayment going down before the tile goes back.

Step 3

Who Does What

Part of the job	Who usually does it	Get in writing
Roof inspection and roof work	A licensed roofing contractor (C-39)	The scope, the products and the workmanship warranty
Removing and reinstalling the panels	A licensed solar contractor (C-46) or electrical contractor (C-10), or the solar company that owns the system	Who, their license, and the schedule
Mounts and their flashing	Whoever puts the mounts back	Flashing at each mount, and who warrants it
The system and its wiring	The solar or electrical contractor	The system warranty and any permit for the reinstall
Damage to the roof during solar work	The company that did that work	Photos before and after

CSLB lists the license classes that can install solar. A C-46 solar contractor can do other trades only when they're needed to install the solar system.

At GAXWe don't sell or design solar systems. When panels have to come off for a roof job, we arrange it with a licensed C-10 electrical contractor, or your solar company handles it directly.

Step 4

Panels Already on the Roof

Who owns them

If you lease the system or have a power purchase agreement (PPA), the solar company owns it, and they decide who removes it and how. Read the agreement before you schedule the roof.

What the warranty requires

Some solar warranties require the original installer, or one they approve, for a removal and reinstall. Ask before anyone touches the panels.

Timing

The panels should come off right before the roof work starts, not weeks ahead, and go back once the roof is done.

Permits for the reinstall

Some cities want their own permit or inspection for the reinstall. Ask who is pulling it.

Where the panels wait

Ask where the panels and rails will be kept while the roof is open, and who is responsible for them in the meantime.

At GAXIf you own the system outright, we line up the C-10 for you and keep both crews on one schedule.

Conduit runs and a solar panel on a concrete tile roof during a solar reset by GAX Roofing — San Dimas: panels coming off, rails and conduit still in place during the reset.

Finished tile section next to a solar array on a Rancho Cucamonga roof after a GAX Roofing repair — Rancho Cucamonga: day two, finished. Tile back on the section, the array behind it.

Step 5

Mounts, Penetrations and the Tile Around Them

Illustration: cutaway of a solar mount on a concrete tile roof, showing the deck, the underlayment, a deck-level flashing at the attachment, a separate tile-level flashing around the standoff, and the rail — Illustration, not to scale. One mount, two flashings: one at the deck and one at the tile, with the underlayment underneath as the backup. Tap to enlarge.

Every mount is a hole in the roof

Each one needs its own flashing. On tile, that means a flashing at the tile and another at the deck. Sealant around a bracket is a backup, not the seal.

The underlayment under the array

The membrane under the panels is what saves you the day a flashing fails, not a reason to skip one. Ask for it by name.

A map of the attachments

Ask the solar company for the panel layout showing where each attachment goes, and keep it. It tells the next roofer where the holes are.

Broken tile under and around the array

Walking the roof, positioning equipment and drilling mounting points can crack tiles, break grout or damage the underlayment. Older or discontinued tile can be harder to match later.

Conduit, valleys and vents

Rails and conduit shouldn't choke a valley or sit on a vent, and everything taken off for a roof job has to go back the way it came off.

At GAXThe solar company is responsible for damage they caused. We can document it in a written inspection report.

Concrete tile roof under a solar array in San Dimas with broken and missing tiles, leaving the underlayment and deck exposed between the solar mounts — San Dimas: broken and missing tile between the mounts, underlayment showing.

Cracked concrete tile and mounting hardware beside a conduit run on a San Dimas solar roof — San Dimas: a cracked tile at a mount, beside the conduit.

Step 6

Who Warrants What

The roof

The roofer's workmanship warranty covers the roof they installed.

The panels and the system

The solar company's and the manufacturers' terms cover the panels and the array.

The mounts and the holes

Whoever installed or reinstalled the mounts owns those penetrations and any leak they cause. Get that sentence into both contracts.

Work by someone else later

Tell your roofer before another company goes up on the roof. Our warranty, like many, doesn't cover areas another contractor opens or works on afterward without telling us first.

At GAXOur workmanship warranty, 10 years on a replacement, covers the roof we install. The panel removal and reinstall, the mounts and the holes they put in the roof belong to whoever did that work. On one recent job the contract said in writing that the solar company's removal and reinstall doesn't void our workmanship warranty, and that leaks from their mounts or penetrations are on their work.

Before either job

Questions to Put in Both Contracts

Who removes and reinstalls the panels, and what license do they hold?
Do I own the system, or does a lease or PPA decide who can touch it?
Does my solar warranty require the original installer for a removal and reinstall?
Who flashes each mount when the panels go back, and who warrants the mounts and penetrations?
Which underlayment goes under the array, by name?
Who pulls the permits, for the roof and for the reinstall?
Did the solar company give me the Solar Energy System Disclosure Document, and does the contract list the exact equipment and number of panels?

After both jobs

The File to Keep

Keep one folder for the roof and the solar system together. It's what the next roofer, a buyer or a warranty claim will ask for.

Both contracts and every change order
The roof permit and its final sign-off, and the solar permit and its sign-off
The panel layout showing where each attachment goes
Photos of the roof before the panels, of the mounts, and of the finished array
The roofing and underlayment product names and warranties
The solar warranty, and the lease or PPA if there is one
Names and numbers for the roofer and the solar company

At GAXEvery GAX job is documented with photos you keep.

Questions

Frequently Asked

Should I replace my roof before installing solar?

If the roof will need major work in the next several years, usually yes, because the panels have to come off for that work later. Our rule of thumb: if the roof has less than 10 good years left, do the roof first. Have a licensed roofer look before you sign the solar contract.

Who removes solar panels for a roof replacement?

In California, a licensed solar contractor (C-46) or electrical contractor (C-10). If the system is leased or under a PPA, the solar company decides who removes it. Get the name and license in writing.

Will removing my panels void the solar warranty?

It can, if the warranty requires the original installer or one they approve. Read the warranty or ask the solar company before anyone touches the panels.

Does a new roof in California mean I have to add solar?

No. The California Energy Commission's solar requirement in the 2025 energy code applies to newly built single-family homes, not to additions or alterations to existing homes like a reroof.

Who is responsible for leaks around solar mounts?

Whoever installed or reinstalled the mounts. The roofer's workmanship warranty covers the roof they installed, and the mounts and the holes belong to whoever did that work. Put it in writing in both contracts.

Can broken tile under my panels be fixed without a new roof?

Often, yes, but under panels the fix should cover at least the whole section, because you can't warranty work you can't fully see. The panels have to come off first.

Planning solar, or have panels on a roof that needs work? We look at the roof first and tell you what it needs before anyone commits to an array. We don't sell solar. We do four kinds of roofs: asphalt shingle roofs, tile replacement with new tile, tile lift and relay, and flat roofs, across the Inland Empire.