That depends. It is deadly to algae, mold, mildew, fungi, and bacteria. It can be unsafe if you are not properly trained in ladder usage and safety. It can be unsafe if you are not properly trained in the use, application, and storage of chemicals. Even professional roof cleaners can be injured or worse if they become unfocused and stop paying close attention to what they’re doing and to their surroundings as well. We do not recommend roof cleaning as a do-it-yourself type project because of the possibility of injury and the fact that homeowners don’t possess the specialized equipment and knowledge necessary to properly clean a roof. Besides, what price tag can you put on your weekend or vacation? I’m sure that you’ll agree, the cost of a professional roof cleaning is worth not having to spend your precious time off trying to clean your own roof. Remember, it will take a team of at least two experienced professionals with specialized equipment at least an hour and a half to properly clean a roof. For a homeowner that translates to an all day job. (Do you want to spend all day working with your wife on another “honey do” project? If you answered “no” you can get your neighbor to help, but by the time you reciprocate your entire weekend will be shot.) Even if you are willing to use a pump-up or a backpack sprayer, you still don’t have our proprietary recipe, so what ARE you going to put in the sprayer. (Make sure you get it right, ’cause you don’t want to have to do it again.)
The most effective way to remove all the personal danger from roof cleaning is to hire a professional roof cleaner. Trust me, it’s just one of those things you should hire a professional for. When my tonsils needed to be removed, I had plenty of sharp knives and a couple of mirrors on hand. However, even though I am an admitted tightwad, I hired a doctor to remove them. It just made more sense to leave it to a trained professional rather than trying to broaden my horizons. Before you decide that I’m just a fraidycat and try to tackle cleaning your roof all by your lonesome, please hear me out. I cut my own grass, I change my own oil, I even built a 400 square foot shed in my back yard and I even added three new levels to my existing deck, but like Clint Eastwood said, “a man must know his limitations.” Cleaning a roof is not really all that hard either, it’s just that the potential for risk of life, limb, appendage, and property damage is too great unless you have the proper equipment and training. Besides, wouldn’t you rather be golfing, fishing, boating, camping, hiking, watching TV, napping, or doing just about anything else besides trying to figure out how to clean your roof? The figuring it out part is the easy part too. The difficult part is execution, particularly with a pump-up or a backpack sprayer. The one good thing about cleaning your own roof is that you’ll get plenty of exercise just going up and down the ladder every time you empty your sprayer and have to mix up a new batch of roof cleaner. Obviously it’s your call, but roof cleaning can be very dangerous and is one of those things best left to a professional.