One summer, your roof looks completely fine. The next time you check your roof, you notice dark stripes appearing on shingles and green spots forming close to the edges. This may raise the question of whether your roof is aging, and you may begin to consider repairing it.

Each summer, Topper Roofing hears these questions from homeowners throughout Maryland. In many cases, these warning signs don’t mean your roof needs replacing. Identifying the cause early and addressing it at the right time can help extend the life of your roof.

Why Does This Seem to Happen Every Summer?

Moisture may remain on your roof much longer than you would think, especially after rain or a night when it is very humid. Places where mature trees have cast shadows may remain wet even throughout the day. With time, the combination of such circumstances results in the appearance of algae and moss.

This explains why two adjacent houses can differ so much – one may be free from stains or dirt, but the second has them just because it remains wet for a longer time.

Are Those Black Streaks Algae or Is It Moss?

If there are black streaks or some other dark streaks visible on your roof, then chances are you are looking at algae. These streaks tend to develop slowly across the surface of your roof and are often misidentified as dirt or sometimes even mold. Understanding the difference between roof algae and mold can help you better understand what you’re seeing before deciding on the next step.

Moss, unlike algae, is easy to spot because it tends to show up in thick green patches on the roof, especially in areas where the roof is damp or constantly covered by shade.

While algae is more of an aesthetic problem when it comes to your roof, moss is something that you need to pay attention to. This is because, over time, it causes water retention in your roof and lifts the edges of your shingles.

Should You Be Concerned?

Algae can often be seen as merely a cosmetic problem. Although the dark stains might give your roof an aged appearance, it does not necessarily mean that the shingles have been harmed in any way.

This isn’t necessarily the case with moss. As it collects and holds water, it will prolong the period for which parts of your roof will remain wet and exposed, which can eventually lead to early wear or even allow water to seep through the shingles.

We have come across situations when homeowners thought their roof needs replacing, while all they needed was a simple maintenance check. We have also encountered instances where the moss had been ignored for quite some time and had done its damage.

Is It Safe to Clean It Yourself?

Your approach to cleaning can be just as important as the actual cleaning process itself. One common mistake that many homeowners make when trying to clean their roof is using a power washer. Although the use of such equipment is the fastest way to get rid of dirt on your roof, high-pressure water can strip away the granules of asphalt shingles and reduce the lifespan of your roof.

Harsh scrubbing and chemical cleaning can be more dangerous than helpful. Before climbing onto your roof, it’s worth understanding the safe methods for removing roof moss and why certain cleaning techniques are recommended over others.

If you are not sure about the state of your roof and degree of moss growth, it would be wise to inspect it first.

How Can You Help Prevent Algae and Moss?

There are several ways to make your roof less inviting to algae and moss.

• Remove any hanging branches that will block out light and prevent airflow.
• Make sure that there is no build-up of water because the gutters are clogged.
• Get rid of leaves and other debris that retain moisture on the roof.
• Schedule periodic roof inspections to catch small issues before they grow.
• If you are replacing your roof, use algae-resistant shingles, which are designed to help reduce staining caused by algae over time.

When Is It Time to Have Your Roof Inspected?

It might be a good idea to consider scheduling an inspection when you see:

• Recurring moss growth each year.
• Shingles that look lifted or curling.
• Recurring dark streaks despite cleaning.
• Indications of water getting into your house.
• Wet areas of your roof well after it has rained.

A closer look will tell you if you have a simple cosmetic problem, a maintenance issue, or a repair problem that will just get costlier down the road.

Regardless of dark streaks or moss, knowing what the problem is the first step to ensuring that your investment stays intact.

Get Peace of Mind About Your Roof 

At Topper Roofing, we’ve helped Maryland homeowners care for their roofs through every season. We believe the best approach is helping you understand what’s happening before recommending a solution.

If you’d like a professional opinion about the condition of your roof, contact us when you’re ready to schedule an inspection.