Roofs leak under solar panels for a few repeat reasons: an attachment bolted through the shingles without a flashing that laps under the course above, a flashing installed on top of the shingles, an abandoned or misplaced lag hole hidden under the array, or simply old shingles and boots aging under panels that make them hard to see. The fix depends on the cause and on who warranties what, so the first step is finding the source and reading your solar agreement. This page is general information; your roofer, solar company and building department make the final call.
On this page: Signs · Causes · What to check · Repairs · Code basis · When to call
Signs of a leak under an array
- A ceiling stain that started after panels were installed, often in a row matching the rafters.
- In the attic, staining or shiny lag tips along a rafter line below the array.
- Leaks during heavy rain or snowmelt, but not light showers.
- Pest nests or debris piling under the panels, which hold water against the shingles.
Common causes
- Unflashed attachments. A lag bolt through the shingles with only sealant on top.
- Flashing on top of the shingles. The base must slide under the course above to shed water.
- Missed rafters. A lag that missed framing gets pulled out and leaves an open hole, sometimes covered by the panel.
- Old roof under new panels. Shingles, pipe boots and vents under the array keep aging and are hard to inspect.
- Debris dams. Leaves and nests trap water and snow on the upslope side of the array.
What you can check
- From the ground, look for debris and nests at the panel edges and for missing or lifted shingles around the array.
- In the attic, follow the rafters below the array and look for wet wood around lag tips.
- Pull your paperwork. Find the solar installer’s roof-penetration warranty and any rule about who may move the array.
- Do not walk on or between panels. They are slick, fragile and electrically live in daylight.
Repair and reroof options
| Option | When it fits |
|---|---|
| Solar installer reflashes the leaking attachment | The leak is at an attachment still under their warranty |
| Roofer repairs shingles, vents or boots outside the array | The source is not an attachment |
| Detach the array, repair the roof area beneath, reset on new flashed attachments | Leaks or damage sit under the panels |
| Detach, replace the whole roof, reset the array | The roof is near the end of its life or storm damaged |
Fixes that fail: squirting sealant around attachments from the panel edge, patching only where you can reach without moving panels, and laying a new roof around an array that stays in place.
Code basis
The 2024 IRC, section R907, says rooftop solar systems are designed and installed under section R329 and the National Electrical Code (NFPA 70). Section R903.2.1 requires flashing at roof openings, and every attachment through the deck is one. On a reroof, section R908.5 requires flashings and similar parts that are rusted, damaged or deteriorated to be replaced, not reinstalled. Local permit rules for removing and resetting panels vary, so ask your building department.
When to call
Call when a stain appears below an array, after a hailstorm that may have damaged shingles under the panels, or a season before you plan to reroof so the solar company and roofer can line up dates. Related guides: pipe boot leaks, satellite and antenna mounts and the full roof problems guide.
Get the roof side checked
Integrity Roofing and Painting is veteran-owned and family-run since 1990, an Owens Corning Platinum Preferred contractor with 650+ Google reviews. We inspect and photograph the roof around and under the array, tell you whether the leak looks like an attachment or the roof itself, and share that report with your solar company if you want. Colorado Springs area: (719) 488-2800 or a free inspection. Denver metro: (303) 209-0152 or a free Denver inspection. Austin: (512) 610-5897 or a free Austin inspection. Same-business-day reply.
Sources: 2024 IRC Chapter 9, sections R903.2.1, R907 and R908.5 (UpCodes); ARMA, Asphalt Shingle Roofs Are Repairable.
