A solar-ready reroof is a replacement planned so that panels can come off, go back on, or be added later. The roof under an array is hard to inspect, so the sound approach is to renew it while the panels are off the deck.
Roof first, then panels
Solar panels are expected to stay up for a long time, and the layers beneath them wear out unseen. If the underlayment fails under an array, the panels have to come off to reach it. Reroofing before panels go on, or while they are off, avoids that.
The plan matches the sequence to what the homeowner has: panels already on, panels coming later, or none planned.
Removal, reinstall and the permit
Where County rules apply, a reroof needs a building permit. A solar system lifted off and later reinstalled needs a separate solar permit on top (LA County Public Works, BCM 1512, 1 Apr 2025). Cities set their own permit paths.
The solar company usually disconnects and reconnects the electrical side. The roofer sets the dates for the roof work, so the two schedules line up.
What a solar-ready reroof includes
- A plan for panels already on the roof, or coming later
- A scheduled window for the solar company to remove and reinstall
- New underlayment and flashing across the whole roof
- Mount locations flashed into the new roof layers
- A covering suited to the weight and layout of the array
- The building permit, with the solar permit noted where required
When a solar-ready reroof makes sense
- Panels on a roof that is nearing the end of its life
- Panels planned for a roof that needs work first
- Stains inside below the array
- A roof whose underlayment has not been seen in years
Flashing mounts on a new roof
Every mount that is bolted through the roof is a penetration. Each one is flashed into the new roof layers, with the flashing lapped under the covering above and over the covering below. The mounts are set into the framing, not just the deck.
A scope that names the flashing method for mounts makes later inspections simpler.
Cool roof values under panels
The state energy code excludes roof area under solar panels from the cool roof test (California Energy Commission, 2022 Standards), and the City of Los Angeles residential rule steps aside wherever solar is installed (LADWP, 2022).
The exposed roof around the array still faces the test when the reroof passes 50 percent.
Questions about solar and reroofing
How are panel mounts flashed on a new roof?
Each mount is a penetration, flashed into the new roof layers and fastened into the framing. The flashing laps under the covering above and over the covering below. The scope should name the method.
Is the roof beneath solar panels held to cool roof values?
Not in the panel footprint: the state code and the City of Los Angeles rule both exclude it (California Energy Commission, 2022 Standards; LADWP, 2022). The rest of the roof can still fall under the test.
Who coordinates between the roof and the solar company?
Each trade runs its own side. The solar company handles its equipment and any utility paperwork, and the roofer fixes the dates for the roof work so the two schedules mesh. You stay informed on both.
Should an old roof be replaced before new panels go on?
Usually that is the sounder order. The layers under the panels cannot be inspected once they are up, and a failing roof means panels coming down again. Check the roof's condition before the panel contract is signed.
What does solar-ready mean when panels come later?
A roof prepared to accept panels without being disturbed: a sound deck, framing that can bear the load and flashing planned for future mounts. Panels themselves are not included.