Only a few of the tile manufactures have a warranty available online, and even fewer have any literature in them in regards to cleaning. But the main thing is that when questioned, it should support anyone using the proper and preferred methods of soft wash roof cleaning. I have had claims from clients that the use of "bleach" or Chlorine on a tile roof will damage the tiles. We all know this to be false based on everything we have found through years of experience.
We just hired a new employee, who has a background in testing and QA'ing roof tiles in a major roof tile manufacturing plant. I plan to absorb tons of new knowledge and information from him.