Moss Management on Roofs

Posted on: 1 March 2017

Moss on the roof may look alarming, but in most cases, the underlying roof structure is still sound. Still, it isn't a problem you want to ignore. The following guide can help you determine when moss is actually a problem and will provide advice on how to handle it.

Warning signs

Moss grows when conditions are damp and shaded, so moss most often grows on the north side of home or under heavy tree cover. This is why moss alone doesn't mean you have a roof problem. You may have a problem if you notice any of the following, though:

  • Moss growing beneath the shingles and causing them to lift.

  • Lots of gravel in the gutters or on the ground beneath the eaves, which indicates the moisture from the moss is causing the shingles to degrade.

  • Moss growth so heavy that it is impossible to survey the state of the shingles easily.

  • A roof structure that appears to be sagging or uneven beneath the moss.

All of these issues are either a result of moss pushing up shingles and allowing water beneath or of the sodden state and weight of the moss causing the rood structure or shingles to weaken. If any of the above is an issue with your roof, prompt removal of the moss and repair or replacement of the roof may be necessary.

Moss Management

The simplest way to avoid moss problems is to never allow it to get a foothold in the first place. The following are methods to combat moss growth:

  1. Schedule a professional roof cleaning. The contractor will use a moss-killing solution to first kill the moss, and then they will clean it off while taking care that no damage occurs to your shingles.

  2. Trim any overhanging trees to allow more light and air circulation to reach the roof. The combination of more light and drier conditions can help prevent future moss growth.

  3. Call in a roofer to install a zinc strip beneath one of the top rows of shingles on each peak of the roof. Zinc makes it impossible for moss to grow. When these strips are installed, they leach a small amount of zinc out that runs down and coats the roof surface each time it rains. The result is no more moss growth.

For more help with a mossy roof or to fix any damage caused by moss, contact a roofing contractor in your area.