What's Growing Up There? Dealing with Algae, Moss and Roof Gunk

As summer settles in, many Red Deer homeowners may step outside to admire blue skies—only to notice something green growing where it shouldn’t be. Algae and moss are two of the most common post-winter roofing surprises. And while they may seem harmless, these unwelcome guests can shorten your roof’s lifespan and invite costly repairs. At Alberta Roof Experts, we know the damage these growths can cause and why roof cleaning in Red Deer is more than just a cosmetic concern. 

Moss thrives in damp, shaded areas and tends to appear in thick green patches. Algae, on the other hand, shows up as dark streaks or blotches. Both hold moisture against your shingles, which speeds up deterioration. Moss can even lift shingles, allowing water to seep into your home’s underlayers. Left unchecked, that moisture builds up and weakens the entire structure. What looks like simple discolouration could eventually become a leak or even structural rot. 

Roof cleaning in spring is the best way to catch and eliminate these problems early. But cleaning must be done right. High-pressure washing can damage your shingles and void warranties. According to the Canadian Home Builders' Association, homeowners should avoid aggressive methods and instead opt for gentler, approved approaches using soft washing techniques and mild cleaning solutions. This helps preserve your roof while restoring its clean look and function. 

Beyond cleaning, prevention matters too. Moss and algae are more likely to grow where airflow is restricted and debris collects. Overhanging branches, clogged gutters and poor ventilation create the ideal conditions for buildup. Trimming trees, keeping gutters clear and ensuring your attic is properly ventilated are all key steps in making sure your roof dries quickly after storms and snowmelt. 

The good news is that a clean roof doesn’t just look better—it performs better. It sheds water more efficiently, dries faster and reflects sunlight more effectively. That means better energy efficiency, fewer leaks and a longer-lasting roof. The Government of Canada’s climate resilience guide emphasizes roof maintenance as a key part of adapting homes to withstand more frequent extreme weather events. 

If you’re not sure what’s growing up there—or whether it’s causing damage—our team can help. We offer thorough inspections and professional cleaning through our roof maintenance and cleaning services, tailored to Red Deer’s climate. We also back our work with expert assessments and repairs, available through our roof repair services, if needed. 

This spring, don’t let moss and algae sneak under your shingles. Book a cleaning, schedule an inspection and give your home the fresh start it deserves. At Alberta Roof Experts, we’re here to keep your roof clean, protected and ready for Alberta’s next season—whatever it may bring.