Why Are There Black Streaks on My Gutters?

Most people don’t set out to inspect their gutters — that’s just not how real life works. The black streaks usually catch your eye when you’re doing something completely different. Maybe you’re letting the dog out. Maybe you’re grabbing something from the car. And then, out of nowhere, you notice these dark, uneven trails running down the gutters. Homeowners across Sarasota say the same thing: “I swear they weren’t there yesterday… or maybe I just didn’t look closely.” That’s usually when they reach out to CR Gutters, Inc.™ and ask what the streaks mean.

What’s Really Behind Those Streaks in Sarasota

The marks look dramatic, but the cause is surprisingly ordinary for Sarasota. The humid air here settles on everything, including gutters. So, mold and mildew grow. Meanwhile, summer storms make shingles shed tiny grains that wash down the roof. These mix with the moisture, stick to the gutter face, and slowly form darker lines.

A lot of people mention the streaks showing up more on the side of the home that stays shaded or faces the direction storms usually hit. And that makes sense — damp, shaded areas stay wet longer. Homes closer to the coastline in Sarasota also see streaking sooner because the salty air helps the debris cling instead of washing away cleanly.

Cleaning Helps — But Only If the Cause Is Solved

Cleaning the streaks safely usually needs a gentle cleaner and a soft brush. Where things get frustrating is when the marks return right away. That’s often a sign that water is touching the gutter front instead of flowing inside it.

During gutter evaluations throughout Sarasota, the team at CR Gutters, Inc.™ often finds subtle things causing the streaks: a shingle sending water sideways, a section of drip edge slightly off, or a tiny seam drip you can only spot when you’re right under it. None of these are dramatic problems, but they’re enough to cause repeated staining on the same spot every time it rains. Some materials just stain more easily too. Older gutters without an enamel finish tend to hold onto debris almost instantly.

When Streaks Suggest Something More

People tend to describe the same little clues before they realize the streaks are more than surface dirt:

• One patch of gutter seems to “age” faster than the others.
• A faint trail appears after every big rain.
• A specific area always looks damp long after the rest of the gutter dries.

These small details usually point to water flowing where it shouldn’t.

What Cleaning and Inspection Usually Costs

Most homeowners in Sarasota end up spending somewhere between $150 and $350 for a thorough cleaning paired with a careful look at what’s causing the staining. Homes with tall rooflines or older gutter finishes may sit toward the higher end.

Want the Black Streaks Gone for Good?

If you’d like someone to walk around the house with you, take a close look, and explain everything in plain, easy language, call CR Gutters, Inc.™ at (941) 367-2727. We’ll figure out where the streaks are coming from and help keep your Sarasota gutters looking clean longer.