Plenty of people are unaware of the reasons why roof moss is so bad for your home. In fact, many homeowners think roof moss is harmless, if unsightly. There are also quite a few people who believe the roof moss is pretty, lending a charming, quaint appearance to the homes upon which it resides. Unfortunately, this plant can actually be quite harmful. Roof moss can damage your roof, reduce your roof’s life expectancy. It can wreak so much havoc that it could cause the roof to lose its structural integrity, and ultimately render your home unsafe. Yikes! Let’s dive in now to discussing what moss is, why moss growing on your roof is such a bad thing, and how to get rid of this insidious plant!

What Is Moss?

According to Wikipedia, “Mosses are small flowerless plants that typically grow in dense green clumps or mats, often in damp or shady locations…Most mosses rely on the wind to disperse their spores.”

Mosses can grow on a wide variety of natural and man-made surfaces, including on rocks, trees, and the ground, as well as on sidewalks, asphalt, and structures such as homes and buildings. Moss thrives on damp, cool, shady surfaces, but some species have adapted to survive even sunny, dry conditions. Moss is a particular problem in wet, cool areas of the country, such as the Northwest. That’s because mosses rely on the wind to disperse their spores, and since these areas already have ideal conditions for the moss to grow, the plant spreads quickly and is extremely difficult to eradicate. That said, even those living on more temperate climates—like ours here in the Northeast—have to contend with this invasive little plant.

Your roof is more prone to moss growth in shady areas, such as those sheltered by tree branches or taller structures. If left unchecked, particularly during rainy periods, it can grow up to a few inches thick. Moss grows readily on roof shingles and spreads very quickly. It’s important to get it under control before it becomes a problem.


Why Is Roof Moss So Bad?

Roof moss is a difficult problem to contend with. Unfortunately, even when homeowners know that roof moss is a problem, they may mistake it for lichen, mold, or algae, which are not only more easily eradicated, but are also less harmful to roofing. Once the moss thickens, it can be more readily discerned from other types of growth. However, by then it’s causing a serious problem. Moss acts like a sponge, with the ability to soak up huge amounts of rainwater. Unlike a sponge, however, it can’t just be rung out, so the moisture in the water-bloated moss begins to leach through the roofing, soaking the underlayment and eventually reaching the wood sheathing below. Once this happens, the wood begins to decay and grow mold, weakening and warping by degrees, and ultimately affecting the roof’s structural integrity and shortening the life expectancy of your roof.

Once the sheathing is damaged, rainwater and can continue to trickle in, where it can cause mold growth on interior walls and ceilings. This problem is particularly troubling, because mold can cause serious health problems and can even trigger health emergencies in allergy and asthma sufferers.

Of course, all these issues can seriously disrupt your life, especially if your home becomes unsafe to live in until the problems are addressed. Unsurprisingly, moss growth can have a major negative impact on your bank account as well. Depending the severity of the problem, you might need to hire a mold remediation company, a roofing company, and/or a contractor to fix all problems that have cropped up.

How Do I Get Rid of Roof Moss?

There are several ways you can prevent or get rid of roof moss. First, you can try installing zinc or copper flashing along the ridge of your roof. That way, when the rain hits the flashing and runs down your roof, traces of the metals, which are natural herbicides, kill off mold growth as well as prevent new growth. You should also trim back any branches that hang over your roof, and, if possible, move other structures that are shading areas of your roof.

If the growth isn’t yet very thick, you can get at soft-bristle brush or broom and gently slough the moss off your roof. Take care, though, not to brush too vigorously (or use a power washer), or you risk damaging the shingles, which can also shorten the life expectancy of your roof.

If moss has already become entrenched, your best bet is to consult with pros about whether it can be remediated with chemical applications. If the moss is too thick, you might need a new roof, unfortunately. Luckily, there are now new types of shingles available that inhibit moss growth, which would prevent your new roof from developing the same problems.

What Else Do I Need to Know?

Do you have more questions about why roof moss is bad, how to get rid of roof moss, or how moss affects the life expectancy of your roof? Have you tried the above measures, yet still find yourself with a dangerous moss problem? Give George J Keller & Sons a call at 973-927-0963. We’ll be happy to answer any questions you have as well as tell you more about how a new roof with moss-inhibiting shingles can ultimately save you a lot of time, money, and headaches!