+
I was willing to let this go as your customers will probably find this eventually. But, if you want them to know, I will talk about roof cleaning rhetoric.
Myths of Roof Cleaning
1. The dark stains will increase your energy bill. 90% of roofs in the South are black shingles to begin with. Most have stains that are not visible to begin with without close inspection. Common sense dictates that a lighter clored roof with black stains will not have a higher energy cost than a solid colored black roof. Shingles do not offer much insulating quality when compared to the attic insulation and tar paper under them. If anything, a stain colored roof might absorb heat in the winter, helping with energy bills.
2. The dark stains will cause health problems. The stains/mold that are on a roof are the same stains/molds that are on the bark of trees, covering the vegatative landscape and are part of natural climate induced growth. While cleaning roof will make it more pleasing in appearance, it is a fallacy to think that you are saving your health in so doing. Do you wash the North side of trees in your yard to prevent a demise in your health? Certainly a small percentage of the population are allergic to certain spores and molds. As the mold on the shingles does not permeate thru them into the house, it would stand to reason that all roofs in the neighborhood would need to be washed to allay the allergic reaction to the homeowner's outdoor daliances. Maybe I should not have mentioned that. It may become a new marketing tactic.
3. Dark stains will destroy your roof. While some extreme cases may produce lichen or other actual growth, the larger percentage of homes only have black staining. The staining will not harm the roof or have negative implications towards your roof. The lichen will attach and begin to destroy the shingles and should be removed. Black stains should be cleaned for appearance issues only.
My belief is that there is enough work out there to keep everyone busy. I know that a lot of customers will have their roofs cleaned because of the appearance issue. It is an easy sell in and of it's own accord without "tactics". I sleep better at night because of the way I run my business. I do not have to sleep in anyone elses bed so I don't really care how your bed sleeps. Do what you think you can live with.