Below is a partial "cut and paste" excerpt from GAF on how to clean a roof:
"If a new roof is not an option, GAF recommends cleaning the roof with a special mixture. That mixture is: 4 gallons of water, 1 gallon of bleach and 1 cup of TSP"
"What NOT To Do! Do not power wash the shingles to clean the shingles. Some roof cleaning companies offer this service. However, it is not recommended."
From ARMA roofing manufacturers Association-how to clean roofing.
Below is a partial excerpt cut and pasted below from ARMA:
Algae discolorations to remove from roofing surfaces, applying a solution of chlorine bleach, triS phosphate, and water. Solutions for these ingredients depend on the amount of discoloration. Solutions range to one cup TSP and 2.5 gallons each of bleach and water. First, gently disperse this solution on the roofing surface. Avoid scrubbing the surface, as this friction may loosen and remove granules. Caution! High pressure washing systems for algae removal should not be used.
Owens Corning Roofing manufacturers says the same thing:
"USE CHLORINE and TSP" "DO NOT USE A PRESSURE WASHER"
Chuck Bergman Soft Wash Roof Cleaning has been serving Charlotte and Sarasota Counties in Florida since 1991 { Prior to that as Chuck Bergman Pressure Cleaning since 1989 }
With years of experience , it became clear to me that while pressure washing roofs made them look clean, damage was occurring on the roofs. Pressure cleaning machines can only be turned down so far and still accomplish roof cleaning and any amount of pressure, even as low a setting as 300 psi { 3000 to 4000 psi is what most pressure cleaning contractors use } will still remove around 15-20% of the granules that make up the color and protection of your shingle roof per cleaning.
With tile roofs, pressure removes the glazing many tile roofs come with. Pressure also blows pieces of cement that hold the ridge-caps in place off into space! If your tile roof is painted, pressure will blow portions of paint off all over the roof, leaving it in need of an expensive paint job!
I started out strictly as a Pressure washing Company!
So, what to do?
In 1991 I started developing a system to clean roofs without using pressure.I "thought, I was inventing the idea, but it already was being used by a few roof cleaners.
Now these roof cleaning systems are available for purchase commercially.
If you would like your roof restored [most of the time to 95% like new!] using only the gentle method suggested by your roofing manufacturer, call us for a free estimate!
We have been a father and son ONLY business since 1994-so you will always get a professional and never get a crew or a new guy in training on your property!