What to do about Moss on my roof?

The Early Stages of Moss





Its hard to believe that in the sunny Okanagan we would have a problem with moss and algae but more and more we are starting to see it slowly develop on many of our customers homes. (Seen above are the early stages of moss growth on a shingle roof.) 


Although this problem is a lot worse at the coast, its not something that we should simply overlook.


Algae, moss, lichens, or fungal growth are quite common on many different types of roofing materials, particularly on the north side of a lot of homes in Kelowna.  This is because of the shady, damp conditions.


But is this more than just a cosmetic issue?


Unfortunately yes.


Moss can actually be detrimental for the life of your roof and we recommend homeowners handle it at the early stages.  Some problems that moss on your roof cause are listed below…


  • reduces the life of your roof (its roots plant into the actual shingle grit, leaving an exposed small “crater” when removed)
  • grows under your roof shingles and slowly starts to lift them up, exposing your roof to unnecessary moisture buildup
  • holds moisture to your roof and causes wear and cracking from frost damage
  • penetration and separation of the roof shingle materials (caused by the roots)

Moss growing on any roof surface will be quite more severe on shaded areas due to damp cool weather conditions.


Removal and Prevention




When attempting to get rid of moss most homeowners try to remove it forcefully with a broom or even in some cases a pressure washer.  Although this seems like a good idea, I’m going to tell you why this isn’t recommended.


First of all moss is a plant, lets call it a weed since really, its more of a weed then a flower wouldn’t you say?  When removing weeds from your garden or lawn what happens when you simply go over them with your lawn mower or weed wacker?  Well in another week or two you start to see them coming back right?  Most of us know that in order to get rid of weeds we need to remove them at the root.  So we need to view moss in the same way.  The proper way to remove moss is to attack it at the “root” level.  This will prevent it from coming back.


Now since the root of the moss is actually embedded into the roof shingle this makes it a bit more tricky.  If we “brush” the moss off, we simply remove the top part.  Along with that we will take some of the roof grit off, which to be honest isn’t major, but in the long run if we keep doing that we are brushing off years of life from our roof.


What about pressure washing our roof?  This actually removes even more life and shingle grit.  We don’t recommend this.  Again too, it does not remove the root of the moss.


So what do we recommend?


Treating Your Roof 


By far the best way to remove moss and algae from your roof is by treating it with a product that kills it at a root level.  We call this roof cleaning.  Its actually very popular down in the states, especially in coastal cities.  Vancouver as well.  It involves completely covering the roof in a solution (bleach for the most part) that kills all the moss in a matter of minutes.  Roof cleaners usually charge between $1000-$2000 per roof as there is a legit process involved.  You can see a lot of videos of it online.  Some refer to it as “soft washing”.  Currently Next Level Window Cleaning does not offer this exact solution.  But what we do offer is a more eco-friendly product called spray and forget.  Its more of a long game solution.  It usually takes about 3 months to see results.  Here’s how it works.


  1. We treat the entire moss area with the product (a generous amount)  This is best done without removing any moss first as it will soak into the moss better and go down to the root. 
  2. The moss dies, it turns a dark brown color and begins to detach itself from the roof.
  3. We schedule a follow up appointment in 3 months to check up on the condition.  If needed we re-treat thicker areas.
  4. Once dead the moss is quick to remove.
  5. We recommend letting the weather naturally remove the moss (rain and snow runoff)  but we understand that some customers want it gone right away.  In this case we can remove it with a blower or a light broom. 

Selling Your Home and Want It Removed Quicker?

If you are selling your home, or you just want the moss removed quicker because you can’t stand the sight of it, we can do that too.  In some cases we remove all the moss FIRST, using a wire brush.  We are careful to not brush the roof too hard and remove too much grit.  Then we treat the areas with the product.  The product is also known for preventing moss growth and so this process works too.  If you are not in a rush though, we recommend treating the moss first.  It will absorb better and also be easier on your roof.  Check out www.sprayandforget.com for more info on the product!


Next Level Window Cleaning is always learning and educating itself on the safest and top notch industry methods, and standards.  We will always keep you in touch with whats current.  If you have any other questions please give our office a call at 250.826.4843.  We would be happy to explain anything further.





Brandon Gawdun
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