Do Solar Panels Affect Gutter Performance?

Solar panels are a great investment for Seattle homeowners — they lower energy bills, add value, and make use of all that bright light we get between the drizzle. But there’s one thing many people don’t think about until the first big storm hits: how those panels affect the way water drains off the roof.

At CR Gutters, Inc.™, we’ve seen a growing trend in solar-equipped homes. While panels themselves don’t cause leaks, they do change how rainwater flows — and if your gutters aren’t ready for the extra runoff, you can end up with overflows and early wear.

Why Solar Panels Change Water Flow

Quick answer: Yes — runoff from panels increases roof water flow.

Solar panels sit slightly above your roof, creating a smooth, flat surface where water collects and slides off faster than it would from regular shingles. When heavy Seattle rain hits, that water rushes toward the edges all at once instead of trickling down slowly.

The result? Gutters take on a bigger load, especially during steady rainstorms or wind-driven downpours. Over time, smaller gutters may overflow or separate at the seams, letting water pour down siding or pool around the foundation.

You might notice small waterfalls forming under the edges of your panels — a sign that your current system isn’t catching all the water it should.

How to Prevent Overflow and Damage

Try this: Upgrade to 6-inch gutters and install larger downspouts to handle the extra flow.

Most homes in Seattle come with standard 5-inch gutters, which work fine for traditional roofs but can struggle once solar panels are added. The larger 6-inch style holds about 40% more water — enough to handle the surge that comes off smooth panel surfaces.

Here’s what else helps:

• Clean more often: Even a little debris can cause spillovers when water flow increases.
• Add splash guards: They keep fast-moving water from shooting past the edge.
• Check slope and seams: A small adjustment can make a big difference in drainage.
• Inspect after installation: Have a professional check that panel brackets and mounts haven’t disturbed the gutter pitch.

What to Watch For

Stop signs: Overflow right beneath the panels, water streaks on siding, or damp spots along the fascia. These are early warnings that your gutters aren’t keeping up. If left alone, that constant overflow can lead to staining, wood rot, or foundation issues.

Typical Cost

Upgrading to 6-inch gutters typically costs $12–$20 per foot installed, depending on the material and roof height. Larger downspouts or additional guards can add slightly more but provide long-term peace of mind and protection.

Keep Solar Power — and Water Flow — Working Smoothly

Solar panels are great for your energy bills, but your gutters need to keep pace. With the right size and setup, both can work together beautifully through Seattle’s rainy seasons.

If you’ve noticed overflow near your panels or water dripping where it shouldn’t, call CR Gutters, Inc.™ at (253) 447-1419. We’ll make sure your gutter system is sized, sealed, and ready for every downpour — so your roof can do its job, rain or shine.