I am a power washing contractor. I noticed in this message some very big concerns I have about the chemicals you are using and the procedure you are using. You won't know it right away, but you could be destroying your wood if you are doing it the way I read. Shoot me an email, or better yet, give me a call 440-570-5204 and I will help you do it correctly and save yourself a whole lot of money and a whole lot of time. It will also make you wife very happy.
Mike