How To Clean Ugly Black Streaks Off Of Your Gutters

As the seasons pass and your roof endures the elements, homeowners sometimes witness their gutters gradually accumulating a buildup of unsightly black streaks. Dubbed "tiger" or "zebra stripes," these vertical black stains come to be because of a variety of factors. Most commonly, they occur because environmental pollutants react chemically with the aluminum that your gutters are made of. In some cases, the asphalt from your roof mixes with the aluminum, while in others, rainborne pollutants react with the gutter surface. 

Beyond aesthetic concerns, removing these black streaks is in the best interest of your gutters. In fact, they can lead to potential damage to your entire gutter system if left unaddressed. On top of that, the accumulation of grime and debris in the gutters can impede proper drainage, leading to water damage and structural issues for your home.

So how do you remove them? Unfortunately, cleaning your gutter isn't as easy as cleaning a rug or washing a sleeping bag. Because of the chemical nature by which they are formed, typical stain removal or cleaning techniques are rarely sufficient enough to do the trick. But before you dial for professional assistance, hold your receiver. Sometimes, the cost and time involved in waiting for a professional to do the work are more hassle than they're worth, and there are ways in which you can rid your gutters of these stripes on your own. Read on to discover how you can clean those ugly black streaks off of your gutters by yourself. 

Before you start, make sure you have a sturdy ladder and safety gear, including gloves and goggles, to protect your skin and eyes from the chemical residue. Gather a garden hose with a spray nozzle, a scrub brush with stiff bristles, and your gutter cleaning solution. 

Experts from J. Racenstein and Elysian Construction recommend Gutter Zap or Gutter Butter, while users on The Grime Scene suggest a mixture of F-13 and water. These are all commercial gutter cleaners designed to break the chemical reaction that has occurred. While you may be inclined to make your own household cleaner, it may not work as effectively. Also, with a DIY solution, you run the risk of damaging your gutters since you don't know the exact chemical composition and potential reactions it could cause. This is why sticking with products that are formulated specifically for gutters is recommended.

Start by rinsing your gutters with a garden hose to remove loose debris and dirt. Then, gently scrub the black streaks away. Start at one end of the gutter and work your way to the other end. For tougher stains, you may even need a power washer, but avoid using abrasive materials that could scrape the gutter surface. After scrubbing, rinse the gutter thoroughly. Once the gutters are clean, inspect them for any signs of damage or clogs. Make any necessary repairs and consider installing gutter guards to prevent future buildup. To prevent black streaks from returning, regularly clean your gutters and keep them free of debris.