How to Remove Black Streaks From Your Roof

Get a free estimate!

Complete the contact form to get a free same day estimate today!

    Does your roof have unsightly black streaks? Are you wondering how to get rid of them? You’re in luck. Here’s everything you need to know about this roof discoloration and how you should clean it.

    Causes of Black Streaks on Your Roof

    The first step in removing the black streaks from your roof is understanding how they got there in the first place.

    Knowing the cause can help you understand the best methods for removing them and preventing their return. Many assume these streaks are dirt, soot, car exhaust, or mold growth, but they aren’t. These black streaks develop on your roof where blue-green algae, otherwise known as cyanobacteria, grow.

    This common alga reproduces through wind-borne spores. When these spores land somewhere humid with indirect sunlight and a food source, a cyanobacteria colony begins to grow.

    Jacksonville’s warm, wet climate, coupled with the limestone found in most asphalt shingles, make for an ideal breeding ground for algae.

    Remove Black Streaks from Your Roof

    After reading articles about efforts to fight algae blooms within water sources, the prospect of cleaning algae from your roof may seem like a hopeless task. If it is difficult to eradicate from waterways, how much harder is it to clean off surfaces?

    Removing the algae colonies causing black streaks on your roof is, in some ways, more straightforward than controlling their growth in water. There are many different options for roof cleaning.

    Chemical Cleaning

    Cyanobacteria, or the algae that most often causes black roof streaks, are single-celled organisms. Because they are simple organisms, chemical cleaners can be very effective.

    While there are a few different mixtures capable of cleaning the algae stains from your roof, some carry more risk of damaging your roof in the process than others. Likewise, no chemical cleaner can guarantee that the black streaks won’t return.

    You can find a few chemical cleaners specifically designed to remove algae, but any bleach solution works as well. Oxygenated bleach is far more eco-friendly than chlorine bleach, but its effects are subtler.

    Pressure Washing

    Pressure washing is an ideal solution when used correctly and is a fast and effective method of removing the black streaks without breaking your back. However, you have to be careful to choose the correct setting and cleaning solution to avoid damaging your roof.

    Given the risk both to yourself and your roof, hiring a professional roof cleaning service is generally a safer option.

    Prevent Black Streaks from Coming Back

    How can you prevent black streaks from coming back after your roof is clean? Being proactive is the best approach. Make your roof as inhospitable to algae as possible. Since algae need indirect sunlight, food, and moisture to grow, make your roof as sunny and dry as possible.

    Trim trees or overhanging branches that shade your roof. The additional sunlight will speed up water evaporation and make it too warm for the algae to grow.

    When it’s time to replace your roof, look for roofing materials that don’t incorporate limestone since it makes for a perfect food for blue-green algae.

    Work With Your Local Roof Cleaning Professionals

    Ignoring black streaks on your roof can lower your home’s curb appeal and resale value, but, more importantly, it can also slowly damage your roof.

    For expert roof cleaning services, work with our team at As New Again Pressure Washing. Dial (904) 881-9743 to set up an appointment today.

    Recent Posts

    Paver Sealing Jacksonville FL

    Paver Sealing FAQs

    Are you thinking about sealing your walkways, patios, or pool decks this summer? If you’re

    Phone Number
    (904) 881 9743
    Service Area
    Jacksonville, FL, & the Surroundings Areas, Including Orange Park, St. Augustine, & Ponte Vedra

    1433 Romney St #5, Jacksonville, FL 32211

    Hours of Operation
    Monday – Sunday (6:00 AM – 10:00 PM)

    Follow Us
    Scroll to Top