Excellent post Bruce and I have always agreed with the phrase "agree to disagree" and when working for a customer they are ultimately the "boss" in most situations. If knowledge serves me right I believe there is a bigger issue than the statements we are all making. There are organizations and associations that put out recommendations that we all have to deal with and some of them are, in my opinion, incorrect. Ed Burke of the Western Red Cedar Lumber Association and the Association itself do not recommend pressure washing cedar because of all the damage they see from the use of this equipment. Sam Williams of the Forest Products Lab always believed there should be paper written with pressure washing guidelines for wood. What most people do not realize is that it is not the PSI from the machine that should be used in "rinsing" wood. Usually it is the wood professional using a pressure washer that actually has 3 or more white tips with larger orifices to reduce pressure. Wood guys have been soft washing for years this way and really only use the pressure washer to rinse with and to save time rather than using a garden hose (though we do use these when needed too). Now, again from knowledge I do believe that it is the Cedar Shake and Shingle Bureau that recommend a coating after cleaning or pressure washing a cedar shake roof. So while I understand that cleaning will make it look better and if done correctly will in fact extend the life of the shakes, how do you get around the recommendation the the Cedar Shake and Shingle Bureau just as we do regarding pressure washing cedar siding and the recommendation of the Western Red Cedar Lumber Association? I do it through literature I give to my customers and by informing them when I speak with them as well regarding our companies techniques and processes.