Insiders Guide To Keeping Your Roof Clean, Reliable & Safe

Damaging High Pressure (Water) Washing-
High-pressure, pressure-washing (2500 to 6000 PSI of raw power) blasts away debris – but can remove the actual roof material the cleaning process is intended to improve.
Beware of “Gentle” Pressure Washing Claims!
Some cleaners call their High pressure systems rated at 2500-over 6000psi of water “Gentle Cleaning”. It sounds good but can blow holes in roofs and flashings, and cause secondary damage greater than the moss or original problem the service was intended to correct.
“High Pressure” Air Cleaning
High pressure air was originally used to blow loose debris off shake roofs too brittle or damaged to be properly cleaned by pressure washing. It works well for loose debris but using high velocity air to literally strip moss is like a tornado on your roof. If it is used properly, most contractors only follow up with very ineffective long-term treatments that leave your roof discolored for months and once the rain has rinsed the treatment away…so is the moss prevention. That’s why it needs to be done over and over.
“Wire Brush & Scrape” Cleaning
This process typically uses aggressive wire brushes to scrape moss off the surface then coarse brooms to sweep away the dislodged moss. Again most contractors apply ineffective passive treatments!

The problem for composition scraping embedded moss can de-laminate the composition from the fiberglass backing and cause roof damage and failure.

Composition has definition (cracks and crevices) that can be missed by a brush. Moss spores reproduce in the billions. That’s why your roof can be cleaned this way and moss returns almost by the next season. Bacteria and fungus spores re-grow under your shingles…where brushes cant reach. The only way this method works is removing loose moss and debris laying on the roof then applying an active treatment to do the rest to actually eliminate the roots and live, embedded portions that would be damaging to remove by agitation. Reject passive treatments!

The problem for shake (wood) is the wood itself is organic and like a sponge it has pores that hold in spores. Cleaning without an effective treatment is only temporary.

The problem with concrete tile is the size of the areas moss and its roots can hide in. The process is very effective to remove moss from the visible areas but like most other methods, the type of treatment is the critical factor. If the moss isn’t reached, it will re-grow rapidly and if a passive treatment doesn’t actually eliminate it, you invested in a service that becomes very costly due to rapid regrowth. Active treatments last!

The Greatest DANGER With Each Of These Is Using Ineffective and Damaging Treatments Or Worse, None At All!
Passive treatments like zinc powder or liquids don’t eliminate the fungus or the bacteria that caused the moss and algae to begin, they only halt it temporarily. Once its washed off the roof from the rain, its ability to halt moss growth is gone.

Cleaning without a treatment guarantees you’ll have moss back almost immediately. Removing moss and algae by simply removing what you can visibly see is like snapping weeds off at the surface. Spores and bacteria reproduce in the millions and travel by rain, wind and growth.

Misrepresented “Effectiveness” of 3,4., even 5 years MOSS FREE. Some cleaners in order to “win” jobs make claims that their “ttreatment” will last ridiculously long periods of time. The fact is treatments, just like wax on a car, have a lifespan. New debris and weather are a huge factor. Much of the “moss free” condition after a cleaning is complete is due to the fact the cleaning removed much of the spores and fungus…and roof life if they used one of the above methods. Debris needs to be removed regularly and fungus, spores and bacteria needs to be re-treated. This will stop its growth.

Next Page



Pressure washing & uncertified “Air wash” methods! Loose claims of “Gentle” cleaning can permanently damage seals, and strip valuable years of roof life!


Dangerous or ineffective treatments that ruin your roof, damage your home, or worse, do nothing and leave you, your roof and your finances at RISK.


A service with Calibrated AirWash Roof Systems™ or water wash systems when requested, recommended by roofing manufacturers and designed for ACTUAL gentle, thorough cleaning, plus treatments Dangerous to Moss, Not Your Roof!


Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>

clear formSubmit