Of Mildew, Mold & Moss: A Guide To Invasive Roof Flora

As we mentioned on a separate blog post this month, it’s been an incredibly wet and stormy summer here in Toronto, Ontario. This has caused roofs to be threatened not only by falling trees and water, but also by a subtler agent: invasive flora that can grow on your roof, devaluing your property by decreasing the overall aesthetic presentation as well as actually undermining the structural stability of your roof.

If you have to have a flat roof with metal flashing and state of the art weatherproof membranes, this may be less of a problem. For one thing, mildew and mold are repelled by copper and zinc on galvanized sheet metal. When it rains, trace amounts of of copper and zinc are rinsed down the roof, defeating the advance of mildew.

As we also stated in a separate post this month, if you have a flat roof it is incredibly advantageous to apply a reflective, weatherproof layer of roof coating to it. In preparation for the application, you must wash the roof in any case, and once the coating is applied, it is much more difficult for mold to grow, since moisture that accrues cannot penetrate the coating. Of all the roofing companies in Toronto and the GTA, we have the most experience with this, so if you’re thinking of applying reflective coating, contact us.

If you live in Toronto, there’s a pretty good chance that you live in an older house with a pitched roof and asphalt shingles. These types of roofs are much more susceptible to the growth of mold and mildew – it’s simply the downside of living in a gorgeous, historical house. While some types of algae and moss are relatively harmless (some might even say they add a quaint je ne sais quoi to a house), it’s always best to clean them off if you have the opportunity. Asphalt shingles typically have a life span of about 20-30 years in the harsh Canadian climate, and when you need help repairing your roof shingles, or even replacing your roof altogether, mold growth is going to make the job slightly more complicated.

Aside from this strictly “decorative” type of algae, there is certainly flora that can do serious damage to the integrity of your roof as well, opening it up to leaks and other such disasters. Some types of algae will grow in your gutters and downspouts, since they like a damp environment. Algae proliferates through airborne spores, so if there’s moisture on your roof and the wind is blowing, there’s not much you can do to stop it. Metal flashing is a great preventative method, but failing that you may need to remove it yourself, or contact us to come apply a liquid cleaner to kill the mold.

It is extremely important to act quickly, because once the mold eats through the shingles, you’re dealing with more and more problems. First of all, you’ll need to replace the compromised shingles. Secondly, the spores can now spread to the inside of your home, creating unsightly patches in the attic and compromising the air quality and your health. If you have young children, the last thing you want is gross moldy air drifting through the house, since it can be a drain on the immune system. If you have serious mold issues, contact us today to speak to the most experienced roofers in Toronto.