Quick answer
If your roof will need replacing within the next 5 to 10 years, it usually makes sense to replace it before installing solar. Panels last 25 to 30 years, and removing and reinstalling them later for a new roof costs extra and pauses your savings. A roof in good shape with most of its life left can go solar as is.
How old is too old for a roof under solar?
The U.S. Department of Energy advises considering your roof's age and how long until it will need replacement before going solar, without setting a single cutoff. A common rule of thumb from installers is that a roof under about 15 years old usually doesn't need replacing first, while an older one should be inspected.
| Roof | Typical next step |
|---|---|
| Under ~10 years, no damage | Go solar as is |
| 10–20 years old | Have the installer inspect it; repair or replace if wear is showing |
| Near the end of its life, leaks or hail damage | Replace first, ideally coordinated with the solar install |
| Flat or low-slope roof | Check membrane age and condition; tilted racking can still work well |
What does it cost to remove and reinstall panels later?
If the roof fails after solar goes up, the panels have to come off and go back on, a job that usually costs a few thousand dollars on a typical home system, on top of the new roof. The system is also off while the work happens. Ask any installer for their removal-and-reinstall price in writing before you sign.
Should I do the roof and solar at the same time?
Often, yes. The Department of Energy points out that a roof replacement is a natural time to add solar. Doing both together means one round of permits and scaffolding, the new roof is fresh under the panels, and the roofer and installer can coordinate flashing and mounts.
- 1
Get a roof inspection
Ask your solar installer or a roofer to assess remaining life and any hail damage, common across Illinois.
- 2
Check insurance
If storms damaged the roof, a homeowners insurance claim may cover replacement.
- 3
Coordinate warranties
Ask how roof penetrations affect your roofing warranty and who covers leaks around mounts.
- 4
Schedule back to back
Many installers work with roofers or do both; a single project manager keeps the timeline short.
Does solar damage or protect a roof?
Properly installed panels are bolted to the rafters with flashed, sealed mounts, and the panels shade the shingles beneath them from sun and hail. Leaks usually trace back to poor installation, so choose an experienced installer and ask about their workmanship warranty. See how long solar installation takes in Illinois for how roof work fits into the timeline.
Sources
This guide is general information, not tax, legal or financial advice. Incentive programs change, so confirm current terms with your installer, your utility and a tax professional.