A composition roof should last about 25 years if it is given proper care and maintenance. Without maintenance, it can need replacing in as few as 15 years.
CLEANING YOUR ROOF
Most roof cleaners pressure wash. The good aspect about pressure washing is that the roof looks clean and brand new immediately. The bad aspect is the occasional leak. If you make it past that, there is generally a large amount of damage to the roof due to the high water pressure. In the best case scenario, the life of the roof has been reduced. To get the immediate "brand new" appearance, many of the comp granules are washed off along with the moss. The goal is to get more years from the roof. That's why I use an air system to clean off the debris and then treat the roof with Guardian Roof Cleaner to prevent further moss growth. After that, it's just a matter of air cleaning debris off of the roof on a regular basis. That might be once a year or as little as once every three years.
