Alright, guys. I feel like I did this the right way and got the wrong results.
I pre-treated with 3-4% SH and surfactant.
I cleaned with a whisper wash ultra 16" using a 4gpm, 4,000 psi, with 2502 tips.
I post-treated with 5-6% SH and surfactant. (I went a little hot on the post-treatment because I wanted to make sure the lines I was seeing when it was wet, wouldn’t be there when it dried.)
I went back today to see how it looks and it doesn’t look great at all.
However, the sidewalk and back patio look fine. Same method used.
What did I do wrong? I feel like I researched, read and gathered the info from you all and was set-up to do a great job. In fact, after stumbling across this site in August, I put the job off for awhile knowing I needed the right equipment and knowledge and didn’t have it. Maybe I still don’t. (And, yes, I plan to fix it.)
[note: The tire marks happened AFTER I cleaned, post-treated and left the job site. A roofing company vehicle turned around in the driveway and left the marks. smh.]