Myth 4. Roof algae is only a cosmetic issue so it can be ignored for now.

If not cleaned and kept at bay, roof algae has the ability to shave years off the life of your shingles. It’s important to remember that roof algae is a living organism that needs food to continue to grow. Guess what the favorite food of roof algae is? That’s right – your shingles!

Shingle makers now use limestone filler in the manufacturing process, which the algae just loves to chew on. This will result in premature loss of shingle granules and general deterioration.

Shingle granules are vital to the health of your roof and home because they work to deflect UV rays and heat away from your roof’s surface. If they are gone or covered with algae, then you will have a hotter attic and higher AC bills. You’ll also have to replace the roof a lot sooner. With the average new roof topping $10,000, it’s a no-brainer to keep your shingles clean and functional for a fraction of the cost.

Myth 5. The best way to go about removing roof algae is with high pressure.

Next to positioning your home in the path of a tornado, power washing your roof is the worst thing you could possibly do to it. Just because your concrete, deck, and brick siding were pressure cleaned to remove algae stains doesn’t mean you should do it to your shingles.

Don’t you have any idea how flimsy and fragile your shingles are? Don’t you realize how many thousands or tens of thousands of shingle granules will pop right off with the use of a power washing wand? It blows my mind that people think this is a good idea.

Yes, blasting your roof with 2000 psi will remove some of the stains, but if it removes some of your actual roof in the process then what’s the point? If you bought a roof algae remover and somewhere in the instructions it says that you should walk up on your roof with a power washing wand in hand and unleash hell on your shingles, then it’s safe to say that you purchased the wrong product.

Myth 6. Chemical roof cleaning will damage shingles, gutters, and landscaping.

If you’re using the right chemicals with the proper procedures and rinsing techniques then you have nothing to fear. I’ve cleaned hundreds of roofs with non-pressure chemical methods and have never caused damage to someone’s home. I also only clean roofs with a helper present whose sole responsibility is to rinse the heck out of the grass, bushes, and perimeter landscaping so that there’s absolutely no chance of plant damage. We usually do such a good job of rinsing that homeowners notice that their landscaping actually looks especially healthy and vibrant in the days following the cleaning.

ARMA (the Asphalt Roofing Manufacturers Association) and GAF (North America’s largest shingle maker) both recommend that shingles be cleaned with non-pressure, chemical methods, and any home inspector worth his salt would also concur.

Myth 7. It’s only necessary to clean the sections of the roof that have visible stains.

Just because you can’t see algae stains on certain parts of the roof doesn’t mean that it’s not already there and beginning to develop. Keep in mind that in its early stages roof algae is completely invisible to the naked eye. It’s not until the more advanced stages that it actually turns black and becomes visible. So if you can see algae on even one section of your roof that means that it’s probably already taking hold on your entire roof.

I always try to explain this to my customers but occasionally I still get people who don’t believe it and demand that I only do a spot-clean to remove visible stains. I reluctantly oblige their demands but am never surprised when I drive by a year later to see the untreated areas now completely covered in black algae! Then they usually call me back with the standard, “You were right. Can you please come back and clean the whole roof as you originally recommended?”

Myth 8. Ambient temperature has no effect on the effectiveness of a roof.

If you’re using the correct chemical mixture, then it will be most effective when the temperature is above 50 degrees. Below 50, the power of the solution drops off rapidly. If you absolutely must have the roof cleaned on a day when it’s right around 50 or a little bit lower, just keep in mind that the chemicals will need to sit for a little bit longer on the roof to be effective. So instead of giving it five minutes to kill the algae give it 15. Then reapply if necessary. On the flip side, if it’s an extremely hot day you may find that your chemical is evaporating before it even has a chance to kill the algae. In this situation you can simply soak the roof with water to cool it down before applying the chemicals.

Myth 9. Roof cleaning is an easy DIY project that any homeowner can do in an afternoon.

There’s nothing easy or quick about roof cleaning. In fact, if you approach it with a cavalier attitude, you run a good chance of injuring yourself. If you want to have any chance of cleaning your roof safely and effectively then you need to set out a clear plan of attack, have safety procedures in place, and, above all, take your time. Rushing through a roof cleaning only leads to trouble.

Unless you’re one of these guys that absolutely has to do every home improvement job on your own, I would highly recommend that you just find a qualified, non-pressure roof cleaning company in your area. Either you can hire somebody who has the equipment and experience to clean your roof in a few hours or you can spend an entire weekend doing it yourself and risking your life. Your choice.

Myth 10. Roof cleaning companies tend to overprice their work and take advantage of consumers.

I guess I’m always a little disappointed when I tell someone that it will cost $300-$500 to clean their roof and they give me attitude and insinuate that I’m somehow ripping them off. I think people hear that word “cleaning” and they think it should be cheap like carpet cleaning or house cleaning.

Think about it. Does a carpet cleaner spend three hours at your house sweating and getting sunburned? No. Does a carpet cleaner run the possibility of paralysis or death by simply doing his job? No. Does a carpet cleaner spend $100 on chemicals for every single job? No. Can a carpet cleaner offer you a guarantee that the treated surface will stay clean for years to come? No.

There’s so much more that goes into a professional roof cleaning than for any other kind of residential cleaning service that it’s really not even fair to lump them into the same category. As a matter of fact, I actually think that most roof cleaning companies come in too low with their prices when you consider all the variables involved.

I also challenge you to name one other home improvement service that can instantly transform a home’s curb appeal in a single afternoon for under $500. Can’t be done. When you consider that it not only makes your home more beautiful but also extends the life of your expensive roof by a matter of years, I think that having a roof cleaned is one of the smartest and most cost-effective things that a homeowner could possibly do to protect their biggest investment.

So now that I’ve educated you about the myths that surround the roof cleaning industry, I hope you’ll take these words of advice to heart because they represent the straightest talk about this topic that you’re going to find. I’m not here trying to sell a product. I’m telling you like it is because there are too many lies flying around. Either you can buy into one of the myths and be disappointed with the results or you can clean your shingles the right way and be satisfied with your new-looking, beautiful home that is free of roof algae.

RoofCleaningChemicals.com was established in 2008 with the goal of educating the public and other contractors about the proper procedures for cleaning a roof. Today they receive more than 6000 visitors a month.