Hello!
My name is Silas McLean, owner/operator of Victoria Moss Removal. Today I am going to create an informational article to educate all homeowners about moss on your roof and the best practices to deal with it, preserving the health of your roof.
Why Do Our Roofs Have A Moss Problem?
Because of our climate. Victoria is a very humid place, and moss thrives in moisture, it likes to live on asphalt which is why you’ll often find it on your roof or driveway.
As asphalt shingles become more advanced, developers have started to infuse Zinc in asphalt shingles, which prevent moss from growing for a period of time. Unfortunately after 4 - 5 years the Zinc washes away in the rain, and you have to start doing maintenance. The best thing you can do 4 - 5 years after your new roof is installed, is to spray it with a hydrogen peroxide based solution diluted with water, every year or 2 depending on how many trees are surrounding your house, do this even if you have no moss on your roof; preventing the problem before it happens is the healthiest and most cost efficient way to deal with it.
Most, if not all homeowners in Victoria will have a moss problem at some point, so I would recommend having your roof sprayed early to maximize your roof life and bank account.
Side note: If you hire a company to spray a solution and they refuse to be transparent about what they’re using, I would avoid that company, there’s no magic formula and they should be informing you about what they’re using. Also, do not trust Zinc Sulphate because though it’s very effective, it is illegal in the Victoria Municipality and surrounding areas, it’s also very bad for the environment.
As asphalt shingles become more advanced, developers have started to infuse Zinc in asphalt shingles, which prevent moss from growing for a period of time. Unfortunately after 4 - 5 years the Zinc washes away in the rain, and you have to start doing maintenance. The best thing you can do 4 - 5 years after your new roof is installed, is to spray it with a hydrogen peroxide based solution diluted with water, every year or 2 depending on how many trees are surrounding your house, do this even if you have no moss on your roof; preventing the problem before it happens is the healthiest and most cost efficient way to deal with it.
Most, if not all homeowners in Victoria will have a moss problem at some point, so I would recommend having your roof sprayed early to maximize your roof life and bank account.
Side note: If you hire a company to spray a solution and they refuse to be transparent about what they’re using, I would avoid that company, there’s no magic formula and they should be informing you about what they’re using. Also, do not trust Zinc Sulphate because though it’s very effective, it is illegal in the Victoria Municipality and surrounding areas, it’s also very bad for the environment.
Negative Effects Of Moss On The Roof:
- Decreased roof life
- No coverage from insurance
- The roof’s warranty is void
- The value of your home goes down
- Curb appeal
If You Currently Have Moss On Your Roof, You Likely Have To Remove Most Of It Manually
Unless you have a very small amount of moss, you cannot simply apply a solution and leave it, you need to get down to the roots. There are products on the market such as “Spray And Forget”, and they are very misleading because without at least some removal & exposing the roots, you will not get the job done. Today I’m going to teach you the best practices & techniques to deal with your moss problem.
At this point the process of moss eating away at your shingles has already begun, and the more there is & the longer it’s there, the more damage it has done. Moss acts as a sponge and holds water weight which is hard on your shingles, and eventually will destroy them.
If your roof looks healthy, but you notice a little bit of green up there, you may just need a heavy spray, which will take care of it over the course of roughly 2 months. The moss will slowly start to turn brown, then it will turn to powder, and wash away from wind and rain naturally. After it’s gone I recommend giving your clean roof another spray just to take care of any spores, and then you won’t have to worry about it for at least 1 year and often longer. You must apply your solution when the roof is completely dry as if too much moisture is present, it will dilute the solution and become less effective. Here is some imagery to compare your situation to:
At this point the process of moss eating away at your shingles has already begun, and the more there is & the longer it’s there, the more damage it has done. Moss acts as a sponge and holds water weight which is hard on your shingles, and eventually will destroy them.
If your roof looks healthy, but you notice a little bit of green up there, you may just need a heavy spray, which will take care of it over the course of roughly 2 months. The moss will slowly start to turn brown, then it will turn to powder, and wash away from wind and rain naturally. After it’s gone I recommend giving your clean roof another spray just to take care of any spores, and then you won’t have to worry about it for at least 1 year and often longer. You must apply your solution when the roof is completely dry as if too much moisture is present, it will dilute the solution and become less effective. Here is some imagery to compare your situation to:
Depending on the landscape around your house, specifically where any trees are located, you may have to do this process more often than not. 1 year is almost always a safe bet if there are trees directly overhanging your roof, but if there are, you want to keep a close eye on it. Here are some more images & my recommendations:
This roof is pretty safe. There are only 2 small trees close by and it will take more time than usual for spores to travel from those trees as they are lower to the ground. If this were my house I would spray it every 2 years as the spores will eventually make it onto the shingles.
Now here, notice there are quite a few trees close by, this one would probably make it through a year and a half without moss growth, but I would still spray it every year just to be safe.
This one is a little more problematic. If you don’t want to be spraying your roof every 6 - 8 months, I would have that tree trimmed back. You don’t want trees directly overhanging your roof because moss spores drop frequently from trees, and once they’ve found a home, aka your roof, they multiply quickly. Not only that but if there’s a storm and a branch breaks, it could cause direct damage to the roof and even more likely; the gutters.
Now, I want to be clear that any activity on your roof will remove granules (a protective coating that keeps your shingles from cracking in the sun). Luckily shingles are heavily coated with these and they are what makes your shingles last. You want as few granules removed from your roof as possible. Moss is the biggest culprit when it comes to granules being removed, but walking on the roof, scraping it, and anything else you do up there will often loosen some, so you want as little activity up there as possible.
When you have a mossy roof, scraping it isn’t going to destroy it, but it’s not ideal. On the other hand it’s much better to do this and take off some granules than it is to leave the moss up there.
NEVER use a pressure washer to remove moss from your roof, period, driveways and walkways only. This is too much pressure and will take off more grit than moss will, faster. If you ever hire a company to do this for you, make sure you know their process. If a pressure washer is involved, move on to another company.
Last but notleast, make sure the company you hire is insured by WorkSafeBC. I couldn’t tell you how many horror stories I’ve heard where a worker injures themselves on a homeowners property, isn’t insured, then turns around and sues the homeowner. Technically if anyone is working on your property and they aren’t covered, you can be held liable (silly, I know).
A clearance letter will tell you a company’s status with WorkSafeBC. Type into Google “WCB clearance letter” and you can get as many as you want, free of charge.
When you have a mossy roof, scraping it isn’t going to destroy it, but it’s not ideal. On the other hand it’s much better to do this and take off some granules than it is to leave the moss up there.
NEVER use a pressure washer to remove moss from your roof, period, driveways and walkways only. This is too much pressure and will take off more grit than moss will, faster. If you ever hire a company to do this for you, make sure you know their process. If a pressure washer is involved, move on to another company.
Last but notleast, make sure the company you hire is insured by WorkSafeBC. I couldn’t tell you how many horror stories I’ve heard where a worker injures themselves on a homeowners property, isn’t insured, then turns around and sues the homeowner. Technically if anyone is working on your property and they aren’t covered, you can be held liable (silly, I know).
A clearance letter will tell you a company’s status with WorkSafeBC. Type into Google “WCB clearance letter” and you can get as many as you want, free of charge.
The Wire Brush Moss Removal Method
This is a method many moss removal companies including ours use. Depending on how you do it, it can be quite rough on the roof, but it can also be the best possible solution you have depending on how much moss you have up there. Depending on how rooted the moss is, sometimes a wire brush can get right down to the roots with a single swipe of the shingle, other times it will just take off a little piece, which is okay because the solution application will take care of the rest, provided you apply enough of it. The key here is to make sure that if you're using a wire brush to remove the moss, you aren't removing too many granules. You can visually see what you're removing and if you don't get rid of the moss right away, it should be left to spray, this is the most efficient way to do moss removal on your roof by a long shot.
You can find articles online about wire brushes destroying your roof, and I'm here to tell you that it is possible, but if you use it right, it is the best possible solution to your moss problem. Simply spraying moss when you've let it build up will not help, there is too much to deal with without manual removal.
You can find articles online about wire brushes destroying your roof, and I'm here to tell you that it is possible, but if you use it right, it is the best possible solution to your moss problem. Simply spraying moss when you've let it build up will not help, there is too much to deal with without manual removal.