We use a non-pressure system for shingle roofs.  Shingle roofs are cleaned in accordance with the various guidelines available from manufacturers.

The roof is sprayed with a water/chlorine mixture with average proportions of 1:6.  The solution is left on the shingles for approximately 20 to 30 minutes, at which time the technician evaluates the cleanliness of the roof and applies additional spray if required.

Although care is taken not to let the mildicide flow off the roof, the technician will thoroughly water the plants and landscaping adjacent to the house beforehand to minimize any possible absorption.  Wet leaves will repel any “over spray.”  This method has proven to be more effective than covering plants with tarps.  Tarps have a tendency to pool concentrated water and then spill, increasing the likelihood of plant damage.  The landscaping is rinsed at the end of the service to clear off any residual spray.