We love this, and will never straight pressure wash another horizontal surface again. I didn’t even know this kind of machine existed, and wish we’d found it years ago. My husband didn’t put gutters on his barn when we built it, and the concrete in front of it gets green as well as generically dirty, every single year. Pressure washing by wand just isn’t worth the trouble and the time, but this makes the process efficient and supremely satisfying. We’re thrilled and highly recommend for concrete surfaces. Sometime this summer we’re going to empty the barn out and do the whole interior floor. We expect it to look like almost new because this does such a good job.