New Roof and Solar Together: The Order of Work

Whether the roof needs replacing before solar at all is covered in should you replace your roof before solar, and taking an existing array off and putting it back is in solar removal and reinstall for a re-roof.

How the re-roof itself runs, step by step, is in the roof replacement process, and how a mount is sealed against leaks in solar mount flashing.

Roof finished first. The re-roof runs to its final inspection, and then the mounts go into the new covering. On our 2021 Canoga Park job, 42 squares of shingle, the roofing permit was finaled 12 days after it was issued, the solar and service panel permits were paid two days later, and all three permits closed within five weeks of the roofing permit. On a 2021 Encino house, we fixed each standoff to a rafter with its flashing tucked under the shingle course above, so every penetration was a roofing detail.

Interleaved. On a 2022 Granada Hills house, with the roof done by another contractor, the roofer laid the field of the covering in one day, we installed the array, and the roofer came back for a day to close the covering around the mounts. To plan that second visit, the roofer asked how many square feet the array would cover: about 425. Two trades, three visits, one covering.

Either way, agree the order before anyone starts, in writing, along with who flashes the mounts.

Tile roofs. Tile that comes off can go back around the array. On a 2026 Chatsworth house, we stripped the tile from 17 squares, laid synthetic underlayment and composition shingle across that field in a color matched to the tile from a cool-roof approved line, put the original clay tile back around it and set the array on the shingle. On a 2026 Canoga Park house, every tile came off, new underlayment went down, the same tile went back and the array followed. The choices for an old tile roof are compared in repair, relay or new tile.

• The re-roof. An express permit covers a Class A or B covering weighing less than 6 pounds per square foot over solid sheathing. Class A is required in a Very High Fire Hazard Severity Zone, and replacing more than 50% of a house's roof calls for a cool roof product certified by the Cool Roof Rating Council. Panels over the roof don't relieve it of that rule; see the cool-roof rule on a re-roof.
• The solar. Express solar permits are issued online, to contractors only, for rooftop systems on one- or two-family houses of 10 kW or less with a service panel rated 225 amps or less, among other limits; a separate building permit may be needed for the structural support. A system outside those limits goes through plan check; our 2023 Woodland Hills job, with a backup subpanel, had city plan-check corrections in May and the city's final release on June 21.
• The service panel. If the panel is replaced to give the array a place to connect, it has its own permit; on the 2021 Canoga Park job it was a new panel with a 200-amp main breaker.

Outside the city, each building department sets its own permits; how the agencies in Los Angeles County handle a re-roof is in re-roof permits in Los Angeles County by city.

File it early. On the 2026 Canoga Park tile job we filed the application while the roof was open, so the two calendars ran together instead of end to end: roofing permit February 10, application February 21, building department release March 5, permission to operate March 20. On the 2026 Chatsworth job the application was filed the same day the express permit was issued, January 6, and the net meter was set February 18.

Tell the utility what the re-roof changed. On our 2023 Woodland Hills job, the utility's photo review raised a clearance objection to a structure that was no longer there after the re-roof; we explained what had changed on site, and it was accepted the same day.

• the order of work and each trade's dates;
• who pulls which permit and who files with the utility;
• the array footprint and the mount layout, before the roofer orders material;
• who flashes the mounts, and with what;
• who answers for a leak at a mount, in writing.

That last point matters because the shingle maker doesn't warrant the solar installation. Owens Corning's Preferred Protection warranty, in its August 2026 version, excludes damage caused by alterations after the roof is installed, solar panel installation among them, and GAF's position is in roof, solar and installer warranties. On the 2026 Chatsworth job, we confirmed in writing that the roof penetrations are covered by our workmanship warranty.

Other jobs are in our project write-ups; how long the roof part takes is in how long a roof replacement takes. Our California contractor license, CSLB #1032379, carries the C-39 roofing classification alongside B and C-10.

Code sections, rules and figures on this page come from the primary sources below. Codes, local requirements and product terms change; each was verified October 9, 2026.

1. Los Angeles Department of Building and Safety, Express Permits (No Plan Check Required), Information Bulletin P/GI 2026-003, effective January 1,…
2. Contractors State License Board, Description of Classifications (C-10 Electrical, C-39 Roofing, C-46 Solar)
3. Owens Corning, Preferred Protection Limited Lifetime Warranty (Pub. No. 10020609-P, August 2026)