Those of us living in the Greater Vancouver Area and Fraser Valley are used to damp and rainy weather; it’s the price we all pay for living in a beautiful temperate rainforest. We also know the effect this moisture can have on our homes and one of the most obvious effects is the growth of unsightly moss on our roofs.
Moss flourishes on hard, acidic surfaces in shady, humid environments. Vancouver’s constant rain and glut of trees makes any roof a moss-growing paradise, especially where there is lots of shade, dirt and debris for it to feed on.
We first notice moss when it grows on top of shingles where it is clearly visible, but it’s also flourishing between shingles and underneath its edges. As the moss thickens, it will raise and separate the shingles, causing gaps in the roof shingle surface. Moss-loosened shingles are subject to blowing off the roof completely on a windy day, resulting in leakage into the home. The moss also damages the composition of the shingles, wearing them down faster and significantly shortening the lifetime of your roof.
Unfortunately there is nothing we can do to completely prevent moss from growing on a roof but there are measures to control moss growing on the roof.
If you have moss on your roof, chances are it’s flourishing in the shade of the trees surrounding your property or it is on the “cold side” of the home which is normally the Northern elevation. One way to control moss growth is to trim branches or remove the suspect trees completely so that direct sun can reach your roof.
Another way to control moss from growing on your roof is the installation of Zinc strips but this will only last a few years unless you remove the dirt build-up from these Zinc Strips. These MUST be installed correctly otherwise you could end up with potentially greater problems in the near future.
It is a good idea to arrange periodic inspections and repairs from professionals to ensure that you will not have debris and pooling water collecting on your roof which encourages moss growth.
Although there is much debate as to the best way to remove moss, there is one thing we all can agree on; excessive moss on your roof not only looks terrible but can damage your roof.
There are many suggestions floating around the internet on how to kill and remove roof moss. Some recommend using bleach or power washing which may do the trick in the short term, but will damage your roof and shorten its lifespan. It is recommended you use a milder, environmentally safe product such as Wash-Safe . This allows you to remove stains and debris caused by algae and moss without harming your pets or landscaping.