Been doing great house washes for a while now. Every one turned out good. Did one today with some weird results. 3 our of 4 walls turned out perfect. The last (back wall) had some sort of streaking. Now, I know what your thinking.... he soaped from the top down. Nope. I rinse top down, soap from bottom up, dwell for about 10 minutes (never gets a chance to dry), and rinsed section top down. Always the same. All walls turned out great except for this one. I did noticed however, after the initial rinse, that the wall did have some sort of pattern that looked streaky. I figured "wtf" and just went through, soaped it down, let dwell and rinsed. By the end of the job, I walked the homeowner around the house, he was happy and paid me, but as we got back to that back wall, I noticed a streaky pattern on the entire wall. Im wondering...was this pattern covered by dirt before I got there, I did the initial rinse and vaguely noticed it, and then after it dried it was real obvious?