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Is Moss Bad For My Roof?

The big question: Is moss bad for your roof? Do I need to be worried about it? What’s the worst that can happen, anyway?

The answer is simple: Moss is bad for your roof. If your roof has moss on it, roof moss removal is something you need to address sooner rather than later.

Why is moss bad for your roof?

Moss thrives in dark, cool, wet climates. And with all the rain we've experienced here in Maryland, it has definitely been a breeding ground for moss growth! Sure, sometimes moss can give a steeply pitched roof a charming fairy tale look like something straight out of the Enchanted Forest. But there’s a darker side to moss growth. No matter whether you have cedar shakes, tiles, or composite shingles, moss is bad for your roof!

Here’s why:

  • Moisture – By its nature, moss is wet and constant moisture on your roof can cause devastating amounts of rot.

  • Growth – Moss is insidious and grows steadily. As it grows it can push under shingles, tiles, and shakes, pushing them up and creating damage to your roof.

  • Leaks – The damage to your roof caused by moss growth can lead to holes, thin spots, and eventually leaks.

  • Pests – Bugs and rodents may be attracted to moss on your roof. The result is frustrating and hard to eliminate pest infestations.

  • Weight – You’d be surprised at how heavy a big mat of moss can be. Moss is spongy and holds a lot of water. There may be hundreds of pounds of added weight on your roof. That’s weight your roof wasn’t designed to support.

  • Curb Appeal – Are you thinking about selling your home? Moss can be a red flag to picky home buyers and home inspectors, potentially costing you thousands of dollars.

  • HOA Fines – If your HOA is particularly picky, you may face a fine for allowing moss to grow on your roof.

  • Danger – Moss is slick and slippery. You’re much more likely to fall and get seriously hurt if you’re walking on a moss-covered roof!

Moss prevention & removal

An ounce of protection is worth a pound of cure. It’s a cliche for a reason! You may consider contacting a professional roof cleaning and maintenance team for a preventive treatment application and removal. These treatments kill moss and stop moss from growing. On composition and tile roofs, a water-based zinc treatment can be applied that kills any moss. Once the moss is dead, a liquid spray soaks into your shingles, ensuring that new moss doesn’t take root.

Can’t I just pressure wash the moss off of my roof?

Pressure washing can remove moss from the surface of your roof but there are drawbacks:

  1. Pressure washing is NOT recommended for roofs with composition shingles. You’ll damage the shingles and reduce the life of your roof.

  2. Pressure washing can drive moisture deeper into your roof. The result is even more rot and long-term damage.

  3. Pressure washing doesn’t always remove the moss that’s between shingles. That’s why we use compressed air to remove moss from most roofs.

More Moss Prevention Tips:

  1. Have you trees pruned. Branches overhanging the roof can drop moss and encourage additional moss growth.

  2. Keep your gutters clean and unclogged. Moisture leads to moss which leads to more moisture which leads to roof damage!

  3. Get your roof inspected regularly. Stop moss growth before it starts.

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