Most homeowners don’t realize it but cedar shake roofs need to be periodically cleaned. Believe it or not a well maintained cedar roof will last a minimum of 40 years. But again the key is to keep the cedar roof cleaned. It is similar to our teeth. If we don’t periodically have our teeth examined and cleaned, we get buildup on them. After a while, our teeth start to discolor and decay hence cavities. It’s the same principle with cedar shake roofs. Cedar has natural properties to protect it from rot. However if organisms are allowed to infest the cedar, those organisms start to break down the cedar causing it to rot and decay. Go here for the rest of the story.