Dark streaks of algae, tufts of moss, patches of lichen... these organic growths have become commonplace on asphalt shingles here on Cape Cod.  Unfortunately, they're not just ugly: they damage asphalt shingles and reduce the service life of the roof.  This is why many home insurance companies are demanding that their clients' roofs be cleaned.  The damage caused by these organic growths is far more costly to fix than it would have been to prevent.

Roofs are like teeth: keep them clean and they'll not only look better, they'll last longer.

"Huh?"

For the average homeowner, roofs are usually "out of sight and out of mind."  Asphalt (composite) roof shingles are good at keeping out the rain and snow, but they're suceptible to damage from organic growth.  Here's some basics to understand:

We have several biodegradable cleaning solutions to clean asphalt shingle roofs in accordance with your roofing manufacturer's guidelines ( ARMA ). 

We do NOT power wash your asphalt shingles, which is a method recommended against by shingle manufacturers.  Be aware that not all roof cleaners in our area follow ARMA guidelines.

"The OTHER GUY said he'll gently POWER WASH our roof.  What's wrong with that?"

Even "gentle" power washing is too strong for asphalt roof shingles.  Powerwashing will get the roof clean, but at the expense of hidden damage to the delicate outer layer of the shingles.  This is why asphalt roof shingle manufacturers explicitly direct you to not power wash your roof. 

We recommend cleaning a roof at the first sign of trouble: fuzzy dots of moss, dark streaks of algae, or little patches of lichen.  Because some types of roof growth are highly destructive to shingles, it's better for the roof (and your wallet) to address this issue before it becomes severe.

Plan ahead!  If have your roof washed, it shouldn't be done at the last minute before placing your home for sale.  Cleaning a roof is a messy process and - when done per manufacturer's recommendations - results are often not "instant."  Gentle is slow!  For these reasons, plan ahead and schedule your roof cleaning BEFORE the house and trim are painted, the windows washed, and the gardens adjacent to the house are perfectly manicured.

Understood.  We offer some extremely affordable methods of roof cleaning.  These methods rely upon Mother Nature to rinse away dead growth, eliminating the need for costly manual rinsing of your shingles.  

"How do I know WHO to hire?"

What about those zinc "Roof Strips?"

Zinc, copper, and lead flashing has long been observed to inhibit the growth of algae upon an asphalt roof.  Just look at the shingles under a chimney's flashing: those are often the cleanest shingles on an entire asphalt roof.  The reason, basically, is that rain flowing across the flashing becomes slightly poisonous to organic life, and it prevents algae from growing on the shingles below. 

Based upon this observation, it's understandable to think that "Roof strips" will keep a roof clean.  However... we've lost count of all the roofs we've cleaned which had those roof strips installed.  In our experience here on Cape Cod, roof strips need to be installed every 4-6 feet down a roof to actually protect all the shingles.  Additionally, lead and copper are far better than zinc... and they also cost far more. 

We regularly receive calls from manufacturers of roof strips who want us to promote their products to our customers ("and make a little money while we're at it").  We do not, because we have never seen these products work as advertised. 

Keep those trees trimmed back!  Nearby and overhanging trees are a prime factor in the growth of moss, lichen, and algae upon your Cape Cod roof.  We don't do "tree work" but can recommend several local companies to call.