re: Anyone do pressure washing as a side business?

I used to pressure wash concrete a lot working maintenance for a gas station company during the summer. I don't remember it fondly in the heat. frick people who chew gum.

That said I'd imagine it will depend on your ability to line up work, like any other side job whether it's yard work, carpentry, etc. Distance traveling to jobs and maintenance on equipment will eat away at that $100/hr you are envisioning, and it may turn out to be more trouble than it's worth, but if you're willing to put in the effort I'm sure you could put some cash in your pocket.