Consumer Reports® warns NOT to use the chlorine-bleach solution described by the Asphalt Roofing Manufacturers Association due to its damaging effects. Consumer Reports® Senior Editor praised the Roof Shampoo® method after he had his own roof cleaned with Roof Shampoo®.

If the Contractor DOES NOT tell you up front that they are NOT using bleach, then they are very likely using bleach. Roof cleaning contractors who use bleach often don't advertise or tell you that they use bleach because they know homeowners don't want bleach used around their homes. Even when asked directly, some may still deny that they use bleach. Be insistent about your need to know. Here are some clues: If they tell you that they use no pressure and that they follow the shingle manufacturers (ARMA) recommendations, then they are using bleach.

Many contractors who use bleach will use the term "Soft Wash". Or, if they tell you they are using sodium hypochlorite -- you should know that sodium hypochlorite is the chemical name for bleach. They may even tell you they use SH, which is short for sodium hypochlorite - bleach. Some even mix fragrance in with the bleach to mask the smell so you won't know it's bleach.

If you're still not sure, ask the following question just this way: "How will you protect my plants while cleaning my roof?" Any answer other than "We don't need to protect your plants because our product does not harm plants," indicates harmful chemicals are being used. If the answer is something like "We wet down your plants before, during, and after our treatment to protect them," you should suspect that bleach is being used. Other indicators that bleach is being used is the use of a runoff recovery system which attempts to suck up all the toxic runoff during the treatment into a containment vessel. Also, if you are told that your plants will be covered during the roof cleaning process or sprayed with a plant protectant, that is a clear sign that your plants are in danger!

Many roof cleaning contractors who use bleach will mix up their own homemade formulas. They mix high-strength chlorine bleach with an array of varied chemicals such as phosphates, dish and laundry detergents, assorted surfactants, and odor-masking scents to hide the smell of the main ingredient - BLEACH! These haphazard chemical concoctions call into question product reliability, stability, safety and consistency across the board.

Chlorine bleach has an intense chemical odor. The toxic fumes can drift a block away, exposing your neighbors as well.

Some roof cleaning contractors will spray a chemical on your roof and tell you to wait for weeks or months to see the results. Products which do not require rinsing, but depend on the rain to wash away roof stains often take repeated applications to achieve even marginal results. Some roof cleaning companies actually use this consumer grade product and charge you professional rates for it. We call them 'Splash and Dash' operators.