Roof stains are caused by algae, moss and dirt buildup on your roofing system. These stains can appear as streaks or spots that range from green to black. They typically form in areas of the roof where there is standing water or where moisture accumulates, such as near the gutters or along shaded areas of the roof.

Types of Roof Stains
Here are the most common type of roof stains and what they look like.
- Algae growth. Algae will typically form a black or dark green stain on your roof and can spread over time if not taken care of properly.
- Moss. Moss can also cause stains, which appear as greenish-brown patches and streaks that are difficult to remove.
- Dirt. Dirt buildup can cause discoloration in areas where it accumulates, such as near gutters or along the ridge line of your roof.
How to Prevent Roof Stains From Coming Back
The best way to prevent roof stains from coming back is by taking protective measures and regular maintenance.
Protective Measures
One way to prevent roof stains from coming back is by installing zinc strips near the ridge line of your roof. Zinc strips will help deter algae growth by releasing small amounts of zinc oxide into the air, which will kill any existing algae or moss on your roof.
Regular Maintenance
Regular maintenance by a certified roofer is also key to keeping your roof in good condition and free from stains. You should inspect your roof at least once a year for any signs of algae or moss growth, dirt buildup or other damage. Cleaning the gutters regularly can also help reduce the chances of dirt accumulating on shaded areas of your roof.
How to Remove Roof Stains
There are two main ways to remove roof stains:
Pressure Washing
Pressure washing your roof is one way to remove stains. However, it is not recommended by all roofers since it can be dangerous and can cause more damage if not done right.
Cleaning Solutions
Cleaning solutions are a great way to remove stubborn stains and prevent them from coming back. There are many different types of cleaning solutions available on the market specifically designed for roofs. Make sure to read the label and follow all instructions when applying these products as they can be toxic if not used properly.
Call Willi Roofing Services for All Things Roofing
It’s important to take care of roof stains as soon as possible to prevent further damage. Willi Roofing Services in Round Rock, TX, can help. Our expert roofing team would be more than happy to talk to you and give you a free estimate. Fill out our online form or call (512) 394-8234 for a free estimate.