Why are there Streaks and Stains on my Roof?

Residential roofs with stains.

Even if your roof isn’t old or damaged, black streaks and stains running down your roof can damage your home’s curb appeal. It’s unsettling to look at your roof and wonder what is causing the unsightly mess, especially if your roof isn’t due for replacement. The issues can vary from cosmetic to harmful and speaking with a roofing contractor can help get you the answers you need and the solution you want.

Why Streaks and Stains Happen

Most of the time the causes are environmental. Most black streaks and stains are caused by algae called gloeocapsa magma. These algae were once only seen in humid climates but are now present in many parts of the country. Streaks appear after a few years because that’s when the products used on roofing tiles to prevent and treat the algae growth begin to wear down.

Although this is the most common cause of black streaks on a roof, other color staining may mean different things. Tree debris, rust, moss, and soot also leave stains. Your roofing contractor will be able to identify the cause of your staining and recommend a treatment. In some cases, it can be as easy as trimming trees to limit debris. In other cases, such as moss growth due to lack of sunlight and abundant moisture, it can be more complicated to address the cause of the staining.

When to Address the Stains

The danger from this staining comes from moisture and the growth of lichen from the algae and moisture related fungus. Once the lichen begins to grow, the problem is not easy to remove. Additionally, if the staining is from another cause other than algae, simply ignoring the stains as harmless may allow bigger issues to develop that may require replacing the roof. Contacting a roofing contractor when you first notice the staining will let you take care of the issues while they are still cosmetic and relatively inexpensive to address.

Getting Help from a Roofing Contractor

The stains from the algae growth can be removed, although the removal is not always permanent. Typically, a roof cleaning will remove the stains for 2-5 years if done correctly. When speaking with a roofing contractor about roof cleaning for stain removal, it’s important to ask the right questions. Pressure washing with high pressure may make the situation worse. And because many of the cleaning products for roofs contain chemicals such as chlorine, it’s important to ask how your landscaping will be protected from runoff.

When it comes to your roof, it’s always better to err on the side of caution and contact a roofing contractor you trust to get you the answer you need. While streaking and staining don’t always indicate a big problem, getting a cleaning done when the stains first appear can be a much easier fix than waiting until there is significant damage. If your roof is in need of repair, contact us today. We’re happy to help you find solutions to your roofing problems.