Moss, Algae, and Lichen: What’s Growing on Your Roof—and What to Do About It

Why Central Indiana homeowners shouldn’t ignore that green fuzz or dark streaks overhead

Have you spotted green clumps on your roof? Maybe dark streaks running down your shingles or rough, crusty patches that don’t seem to go away?

If so, you’re not alone.

Homeowners across Central Indiana—from Lebanon to Whitestown to Brownsburg—deal with moss, algae, and lichen growing on their roofs. These issues tend to creep in slowly, and they’re easy to overlook at first. But left alone, they can lead to real damage over time.

At Eagle Restoration, we’ve seen what these growths can do: weakened shingles, leaks, mold in the attic, and roofs that wear out far sooner than they should. So let’s break it down—what’s growing on your roof, why it’s there, and what you can do about it.

What Are Moss, Algae, and Lichen?

They might look similar from the street, but moss, algae, and lichen are each a little different—and each brings its own set of problems.

Moss

Moss is easy to spot. It grows in thick, green clumps and thrives in shaded, damp areas—like the north-facing side of your roof or under heavy tree cover. If you live in one of the more wooded neighborhoods around Zionsville, Lebanon, or the outskirts of Brownsburg, you’ve probably seen it.

The issue? Moss holds moisture like a sponge. Over time, it can lift shingles, create soft spots, and trap water where it doesn’t belong. That’s how small roofing problems turn into bigger, more expensive ones.

Algae

Algae usually shows up as dark black or green streaks running down asphalt shingles. You’ll often see it on older homes or in neighborhoods with lots of mature trees, like parts of Whitestown or Carmel. What you’re seeing is typically Gloeocapsa magma, a type of airborne algae that feeds on the limestone filler in shingles.

Algae won’t destroy your roof overnight, but it can age the look of your home quickly. And it creates the kind of damp, shaded environment where moss and lichen love to move in.

Lichen

Lichen is a bit more stubborn. It’s a mix of algae and fungus that forms flat, crusty patches in gray, green, or bluish tones. Once it grabs onto your shingles, it’s tough to remove without damaging the roofing material underneath. Lichen can eat into the surface of your shingles over time, causing permanent pitting or weakening.

It usually shows up in areas where algae has been hanging around for a while—so if you’re seeing both, your roof could be overdue for some attention.

Why It’s Common in Central Indiana

Central Indiana’s climate makes it easy for moss, algae, and lichen to take hold. We have humid summers, lots of shade from old-growth trees, and frequent pop-up storms that leave roofs wet for hours at a time.

Combine all that moisture with areas of your roof that don’t dry out quickly—like under overhanging branches or next to neighboring houses—and you’ve got the perfect conditions for biological growth.

It’s especially common in:

• Older neighborhoods in Lebanon or Zionsville with mature trees

• Suburban developments in Whitestown or Brownsburg where rooflines are shaded much of the day

• Homes near wooded areas, creeks, or low-lying terrain

Why You Shouldn’t Ignore It

Here’s the thing—moss, algae, and lichen aren’t just cosmetic issues. If they’re showing up on your roof, it means your shingles are staying damp longer than they should.

And that can lead to:

• Premature shingle deterioration

• Leaks from lifting or cracked shingles

• Rot or mold in the attic or roof decking

• Decreased energy efficiency

• Reduced curb appeal and home value

Even if your roof isn’t leaking today, these signs mean it could be vulnerable—and waiting too long can turn a $500 maintenance fix into a $10,000 roof replacement.

What You Can Do About It

So, how do you deal with roof growth without causing more harm than good?

1. Start with a Professional Inspection

Every home is different. Before we recommend a cleaning, we inspect your roof to see what type of growth you have, how widespread it is, and whether your shingles have already started to break down.

At Eagle Restoration, we offer free roof inspections for homeowners across Central Indiana. We serve Lebanon, Zionsville, Whitestown, Brownsburg, Carmel, and surrounding areas.

2. Avoid Pressure Washing

Pressure washers might seem like an easy fix, but they can cause more damage than the moss itself. High-pressure water can strip granules from asphalt shingles, loosen flashing, or force water under the roof.

Instead, we use low-pressure soft wash techniques that remove growth without damaging your roof.

3. Improve Ventilation and Drainage

Sometimes moss and algae aren’t just an outside issue. Poor attic ventilation can trap warm, humid air under the roof deck, creating a perfect environment for growth. During our inspection, we’ll check your attic airflow and gutter system to see if they’re contributing to the problem.

4. Trim Trees and Clear Debris

If your roof spends most of the day in shade, especially from overhanging tree limbs, it’s going to stay damp longer. Trimming back branches and keeping your gutters clear can go a long way in keeping your roof dry and clean.

5. Prevent It From Coming Back

If growth has been a recurring issue, we can install zinc or copper strips along the ridge of your roof. When it rains, tiny particles from the metal run down your shingles and naturally kill moss and algae. It’s a simple upgrade that helps keep your roof cleaner for years.

When to Call Eagle Restoration

If you’re seeing signs of growth—or just not sure what’s going on up there—give us a call. Trying to clean it yourself could cause more harm than good, especially if you’re dealing with lichen or heavy moss buildup.

We’ll take a look, give you a straightforward explanation of what’s happening, and let you know what (if anything) needs to be done.

Don’t Wait Until Your Roof Starts Leaking

Moss, algae, and lichen are slow-moving problems—but they are problems. Ignoring them can shorten your roof’s lifespan and lead to bigger issues down the road.

A simple inspection now can save you money, hassle, and the headache of an emergency repair later.

Call Eagle Restoration today to schedule your free roof inspection in Lebanon, Zionsville, Whitestown, Brownsburg, or anywhere nearby. We’re here to help you keep your roof clean, strong, and ready for the seasons ahead.