Don't feel bad if you didn't know. Few homeowners realize they can actually extend the life of their cedar shake roof by keeping it clean. In fact, very few even know this process is available. This is unfortunate as it causes premature replacement at just 20-25 years in almost all of these roofs. There is a better way.
Replacing your cedar roof is an expensive process running $20,000 to $50,000 or more. It will eventually need to be done. But why do it any sooner than necessary? It's messy, too. Your attic will have lots of debris in it no matter how careful the workers are. Often times, gutter covers have to be removed and some types will void your roof warranty so you may need new ones. Gutters get bent and landscaping gets trampled. Homes designed for a cedar roof may have serious ventilation issues when replaced with other roofing types causing wrinkles and ripples in the shingles adding additional headaches and expense. All of these things happened when I had mine replaced.