This is a more complicated question than most homeowners realize. There are many factors that go into a roof moss quote including:
There are many different processes or methods for removing moss from a roof surface. MossAway uses the process that we feel is the safest and most effective which we call the "Brush & Treat" method. Hand brush removal of the moss is labour intensive but the quality of removal is extremely high compared to any power form of physical removal. It is also considerably safer for your roof than other removal methods. We would never recommend that a homeowner allow a contractor to pressure wash or "soft wash" your asphalt shingles. We have plenty of photos of severely damaged rooftops that were pressure washed - stay tuned for that post later in the month.
MossAway has an average service cost of just $750 across all services conducted in 2018 with invoices ranging from just $350 to just over $2500. [Edit: June 2022] It's important to note that the global pandemic, rising fuel prices, and supply chain issues have dramatically increased costs since this post. In 2022, the average quote is currently closer to $1150, with the largest residential projects typically hovering around $3500. Since this post in 2018, we have also implemented the moss-free membership. Customers booking roof moss removal & treatment projects with MossAway are treated to free yearly reviews of their roof. MossAway catches moss growth early, aiming to spot-treat for around $150-250, only if you need it, every 2 - 4 years. This should greatly increase the longevity of our service and the lifespan of your roof. See our more recent articles for more details. [End of edit]
Are there even more affordable methods? This is quite reasonably the most affordable process possible to safely & effectively remove moss from an asphalt rooftop. Every so often a customer sends us a lower competitor quote, and almost every lower quote we've received was from a "guy with a truck and ladder" outfit. Do keep in mind - our industry sees some of the highest WCB rates of any industry, quality workers for this time of work do not come cheap, and if you employ someone who is not covered by WCB and/or doesn't carry liability insurance you could be in for quite the unpleasant experience. For more on that, check out our post about why WorkSafe coverage is so important when selecting a contractor, coming out later this month.