I had the guys at Service Source clean our deck and it looks like new. I could not believe the dirt and algae that they cleaned off and did not do any damage to the wood or my shrubs that surround the deck. Their price was a little higher than my other quotes, but no one else took the time to assure me HOW they could clean such a dirty deck without harming the surface. They also assured me they would not damage my shrubs. I'm glad I used them and will not wait so long the next time!