I get asked this question a lot. The true answer is this; when your roof is properly maintained it should NEVER need to be cleaned. Gutter cleaning and blowing debris off the roof is a normal maintenance item but washing the roof is a restoration activity.
Our SoftWash roof cleanings come with a limited 3-year warranty but realistically, there is nothing in the product applied to the roof that actually prevents new growth. The SoftWash sterilizes the roof and it takes time for the nutrient base to reestablish to start the process again.
Now if you want a real moss and mildew guarantee, we can apply our Voy Seal Coat product to guarantee moss and mildew will not return for many years to come. This product is a blend of micro-biocides and an acrylic binding agent. Not only will this product prevent moss and mildew, but the bonding agent repairs the bonds between the roofing and the granules. If you really want the full life from your roof, ask about the Voy Seal And Coat when you buy a new home, replace your roof or have your roof cleaned.
And remember, your home isn’t clean until it’s Voy clean!!