Solar panels are designed to last for decades, so it makes sense to ask whether the roof below them can last just as long. If the roof needs replacement soon after the system is installed, the panels must be removed and reinstalled, adding cost and complexity. A little planning before you sign a solar contract can avoid that outcome.
Start With an Honest Roof Assessment
Ask a licensed roofer to inspect the roof and estimate its remaining life. They will look at the age and condition of the roofing material, the underlayment, flashing, decking and any areas with prior leaks. Photographs and a written report give you something to share with solar installers and can be useful for warranty purposes.
General Rules of Thumb
- If an asphalt shingle roof is already in the second half of its expected life, consider replacing it first.
- If there are signs of leaks, soft decking or widespread shingle failure, repair or replace before panels are mounted.
- If the roof is newer and in good shape, it may be ready for solar with no work beyond routine maintenance.
- For tile, metal and slate roofs, which often last longer, ask for an inspection of the underlayment and flashing, as those parts may age faster than the surface.
The Cost of Doing It Later
Removing and reinstalling a solar array typically involves disconnecting the system, detaching panels and racking, replacing the roof and then reinstalling and reconnecting everything, often with a new inspection. The labor can be a meaningful expense, and the system will be offline during the work. Replacing the roof first usually costs less overall than doing it afterward.
Coordinate the Projects
- Share roof reports with solar companies so they can plan the layout around the roof's condition.
- Ask the roofer to coordinate flashing and penetrations with the solar installer.
- Schedule the roof first, with the solar installation to follow once the new surface is complete.
- Keep warranty documents from both contractors, and ask how each affects the other.
Roofing Materials That Pair Well With Solar
Standing seam metal roofing can be well suited to solar because panels can be attached with clamps that do not penetrate the metal. Architectural asphalt shingles are also common and well understood by installers. Tile roofs can host solar but require careful handling. Discuss your options with both professionals.
Consider Other Factors
If you plan to re-roof, it may be an opportunity to upgrade attic insulation or ventilation, add a roof deck repair or adjust the layout to reduce shading from vents and skylights. A roof with fewer obstructions may allow a cleaner panel layout.
Permits and Inspections
Re-roofing typically requires a permit, and solar installations require their own permits and inspections. Confirm that each contractor handles their portion, and that the final documentation is delivered to you.
Make a Decision With Numbers
Ask for itemized quotes for roof work and for solar, with and without the roof project, and compare timelines. Careful sequencing can protect your investment in both the roof and the solar system.