What is Causing Streaking and Discoloration on My Roof?
Algae Growth from Humid Conditions is What is Streaking Your Asphalt Roof in Maryland!
Are you noticing dark streaks on your asphalt roof? Darker spots on black, grey, or brown shingles that look like long lines of discoloration? The answer is likely algae.
In warm, humid climates like Frederick’s and the surrounding areas in Maryland, roofs become a great place for algae to grow. Most specifically, Gloeocapsa magma algae, a mostly harmless but unsightly algae. Those dark spots are the algae in action, while green spots are actually moss growth and a completely different (and more serious!) problem.
Why Do I Have Algae Growth on My Roof?
Homeowners spot discoloration and streaking on their roof, often when roofs face north or are shadowed by many trees and other shade structures that prevent the sun from naturally drying out asphalt shingles. The trapped moisture becomes a breeding ground for the algae, creating the discoloration homeowners see. It is not a sign of neglect or roofing failure, but can be unsightly.
If you’re noticing discoloration on your roof and want answers – Politz Enterprises Roofing is here to help. Find out if you need a full roof replacement due to algae growth, how to get rid of roof streaking, and what you can do to maintain and prevent algae growth on your roof in Maryland.
Treating Algae Streaks on Asphalt Roofs
While algae streaks on asphalt roofs are not an immediate problem, they can be unsightly and ruin the aesthetic of a roof. Most homeowners want to treat roof streaking to improve their curb appeal and sometimes even their home value.
In general, staying on top of roof streaking and treating algae streaks can prevent long-term damage to a roof. Algae streaks may indicate a roof that is remaining wet when it should be drying, and over time, the algae may degrade the UV protection of the asphalt shingles.
To treat roof streaking on asphalt shingles from algae growth, you simply need to get a chloride mix or algae treatment. We recommend always calling a professional roofer for roof cleaning and algae growth; roofs can become slippery, and trained roofing professionals will know how to check for additional damage during the cleaning process.
However, some homeowners can clean roof discoloration themselves with DIY roof cleaning. Always be safe on the roof and take caution. Politz Enterprises officially advises calling a professional for safety.
How to Clean Roof Streaking:
- Obtain a chloride mixture safe for asphalt roofing materials or another approved algaecide cleaning agent
- Safely apply the cleaning solution to the roof, covering the gutters and streaked portions of the roof completely
- Let the moisture set for 20 minutes before rinsing entirely with water
- You should expect a few weeks for the discoloration to fade
Consider Streak-Proof Roof Replacement For Severe Algae Staining
What are algae-proof shingles?
Algae-proof shingles and roof replacement are shingles made with metals in addition to the asphalt. Lichen and algae do not attach to metals, which stops the growth, discoloration, and streaking, even in humid climates or shaded areas.
Is your discoloration and roof streaking beyond repair? Are you tired of trying to clean your roof but keep coming back every few years due to roof streaking? A roof replacement with streak-proof shingles and algae-resistant materials could be a better option.
Why would I need algae-resistant shingles?
While algae in the short-term is not harmful to your roof, it can be an indicator of other problems (like pooling water or not enough exposure to sunlight) and overtime algae turn into lichen, which degrades the coating of shingles and can destroy a UV coating, putting the roof at more risk of damage.
If you’ve been unable to remove roof discoloration, it could be because you have lichen, not algae, which is much harder to remove and resistant to most cleaners. Even if you’re tired of roof discoloration reappearing, a roof replacement with algae-proof shingles could be a huge improvement to maintaining curb appeal and your roof’s appearance.
Maintaining a Streak-Free Roof in Humid Climates
- Help your roof get as much sun exposure as possible to dry out wet spots
- Trim back branches and trees for more sun exposure
- Remove debris that may trap moisture and encourage algae growth
- Clean gutters to prevent pooling water, excess moisture, or collecting debris
- Inspect for pooling, dips, or other problem areas on your roof to catch issues early
Call Politz Enterprises for a Roof Inspection in Maryland
Are you worried about roof streaking or damage from collecting moisture? Do you think lichen may have worn away the protective coating of your shingles? Politz Enterprises Roofing in Frederick can help.
With over 60 years of experience, Politz Roofing is a go-to name in Maryland. We have helped homeowners inspect their discolored roofs, found what is causing their roof streaking, and provided roof replacements and expert advice.
Whether you’re in Maryland, Virginia, or West Virginia, you can call us for a roof inspection today.
Frequently Asked Questions
What causes dark streaks and discoloration on my asphalt roof in Maryland?
The dark streaks are most likely caused by Gloeocapsa magma, an algae that thrives in warm, humid climates like Maryland’s. It commonly appears on roofs with limited sunlight due to tree coverage or a north-facing slope.
Is roof streaking from algae a sign of damage or neglect?
No, algae streaking is not a sign of roof damage or neglect. However, it is unsightly and can eventually degrade the UV protection of shingles if left untreated.
How can I clean algae streaks off my roof?
Use a chloride mixture or algaecide safe for asphalt shingles, apply it to the streaked areas, let it sit for 20 minutes, and rinse thoroughly with water. Always use caution or hire a professional roofer for safety.
When should I consider replacing my roof due to streaking?
If algae or lichen growth is severe and recurring despite cleaning, or if discoloration has caused aesthetic or structural concerns, it may be time to replace your roof with algae-resistant, streak-proof shingles.
How can I prevent roof streaking in the future?
Increase sun exposure by trimming trees, clean gutters regularly, remove debris, inspect for moisture pooling, and consider algae-resistant shingles for long-term prevention.