How to Clean a Shingle Roof

How to Clean a Shingle RoofUgly black or green roof stains can significantly detract from your homes appearance but did you know that the stains are actually live algae eating your roof? If left untreated algae, moss and lichens can shorten the life expectancy of your roof by up to 50%.  If you have a 30 year roof on your home and it gets infected and it’s not maintained you might only get 15 years out of it before you have to replace it.

Cleaning a roof can be dangerous and is better left to the pros who have the proper training and safety gear to get the job done right and safely.

There are several methods used to clean shingle roofs but only one is approved by the Asphalt Roofing Manufactures Association (ARMA) and that is the use of diluted bleach to kill the algae, moss and lichens.

With this method a diluted bleach solution is sprayed onto the roof to kill the algae in the infected areas. This will remove the black algae immediately and the green moss and lichens will die and turn white. They may take up to 90 days to disintegrate and fall off the roof.

In most cases the algae will be on the shady side of the roof and not the sunny side. It is not required to clean shingles that show no signs of infection but some contractors will tell you they have to clean the whole roof or they won’t guarantee their work. This seems to be a ploy to get homeowners to spend more money with the contractor for work that is not necessary. If you find a contractor is insisting he clean the whole roof and one side is already clean just look for another contractor

Some contractors use variations of the approved method that are not recommended by ARMA namely not rinsing the bleach off the roof. These contractors will not rinse the bleach off the roof contrary to what ARMA recommends. They “leave it up to nature” to rinse the roof the next time it rains. There are several problems with not rinsing the roof.

Bleach has salt in it and is corrosive so leaving it to dry on shingles and inside your aluminum gutters can cause corrosion and shingle deterioration. In addition to this when it finally does rain the salt will be reactivated and run down the gutters out on to your lawn or in your flowerbeds and kill everything it touches. Make sure your contractor is going to rinse the first flush off your roof and rinse the gutters out to protect your property.

Another method that is used by Roof Shampoo™ is the use of strong chemicals and a rotary surface cleaner that is rolled up and down the roof power washing the shingles. Power washing shingles will remove the granules off the shingles and cause them to deteriorate prematurely. The wheels of the machine rolling up and the roof can damage the shingle and remove granules also. This method is not approved by ARMA and can seriously damage your roof.

Power washing with a traditional power washer is also not recommended as the high pressure can damage shingles and remove granules.

You can expect a roof cleaning that is performed using the ARMA approved method to last 3-5 years depending on the amount of trees on your property and the amount of shade. The algae is windblown like seeds from dandelions so having a neighbor that has algae on their roof can spread it to your roof rather quickly.

Cleaning your roof is a regular part of home maintenance that will not only improve your curb appeal but cleaning it will also prolong your roofs life expectancy.

If you’d like a free no obligation consultation with one of our friendly Customer Care Specialists please feel free to call us at 732-775-1242

Your home may not be brand new, but we’ll make it look like it is!