A fuzzy green roof is a ubiquitous sight in Victoria. It is also a decidedly West-coast occurrence. Due to our precipitation levels and unique climate, you would be hard pressed to find such a thing east of the Cascade Mountains. Perhaps you appreciate the fairy-tale look it adds to your home, but there is good reason why you as a homeowner should be concerned with its effects on your roof and its lifespan. Why is that?
It has been wisely stated that when humans complete any construction project, nature immediately starts taking it back. Hydrostatic pressure starts trying to squeeze water into our basements, plants and animals come knocking in search of shelter or nutrients, and gravity starts trying to pull everything to the ground. A very obvious way in which nature encroaches is when moss and algae begins to live in our roof coverings.
Successful construction throughout history has centered around maintaining a certain harmony with the environment around us. A key principle to that end is ensuring a building’s ability to shed moisture efficiently and dry quickly, especially in wet climates like ours. Moss works against this ideal by absorbing moisture and holding it against our roof, sometimes forcing it’s way into vulnerable areas of our roof system. This can dramatically reduce the lifespan of our roof coverings and in some cases, if left unchecked, can even lead to eye-popping repair bills in situations where holes have been created in roof sheathing and mold and mildew have found their way into the attic space. Moss, and all vegetation, would love for nothing more than your home to go back to being dirt again. Fortunately it is a relatively easy problem to avoid, as long as you stay on top of it.
There are many maintenance companies on the island that will gladly take care of the problem for you at a reasonable cost. If you are so inclined, you can also take care of it yourself with a little research and a lot of ladder safety. If the moss is removed thoroughly and treated with the appropriate chemicals, it may be 2 years before you have to turn your attention to it again. However, do not simply ignore the problem or it may compound!
Incidentally, for similar reasons, it is a good idea to remove bird poop from off your roof as well! It is acidic and if left for long periods can also actually weaken and damage your roof coverings. With that, I wish that all your roofs will remain moss and poop free!