Alright, so I tackled cleaning my concrete patio the other day and thought I’d share my experience. Figured some of you might be wondering, “how much psi do I really need to clean concrete?” Let me break it down.

First off, I had this old, kinda green and grimy patio. Looked like it hadn't seen the light of day in ages. I started by doing some research online, and boy, the opinions are all over the place. Some folks swear by super high PSI, like 3000 or more. Others say you’ll wreck your concrete with that kind of power.

I decided to start cautiously. My pressure washer has adjustable settings, which is super handy. I filled up the soap reservoir with some concrete cleaner I picked up from the hardware store – nothing fancy, just the standard stuff. I gave the patio a good pre-soak with the cleaner, letting it sit for about 10 minutes to loosen up the grime.

Here's where the testing began. I started with the pressure washer set at around 1500 PSI. Used a wide fan nozzle to avoid etching lines into the concrete. I went over a small section, moving slowly and steadily. Honestly? Not much happened. Some surface dirt came off, but the green algae stuff was still clinging on like it owned the place.

Okay, time to bump things up a notch. I cranked the pressure up to about 2000 PSI. This time, I could see a definite difference. The grime started to lift a bit easier. I still kept the wide fan nozzle and made sure to keep a good distance from the surface (about 8-10 inches). This setting worked reasonably well, but it was still taking a lot of passes to get the concrete clean.

I was getting impatient, so I carefully went up to 2500 PSI. Whoa! That's where the magic happened. The green stuff was practically jumping off the concrete. The dirt just melted away. I was careful to keep moving and not linger in one spot for too long to avoid any damage. I also kept the fan nozzle moving in a consistent pattern, overlapping each pass slightly.

For the really stubborn spots – you know, those areas where the algae had really taken root – I used a turbo nozzle. This nozzle concentrates the water into a powerful spinning jet. It’s great for tough grime, but you gotta be extra careful. I kept the turbo nozzle moving constantly and avoided holding it in one spot for more than a second. It blasted those stubborn spots clean in no time, but I definitely wouldn't recommend using it on the whole patio.

After pressure washing the whole area, I rinsed everything down with clean water. I have to say, the difference was night and day. My patio went from green and grimy to looking almost new again.

So, the takeaway? For my concrete patio, 2500 PSI seemed to be the sweet spot. But remember, every concrete surface is different. The age, condition, and sealant (if any) will all affect how much pressure you can safely use. Always start low and increase gradually until you find what works best for you. And for those really tough spots, a turbo nozzle can be a lifesaver – just use it sparingly and with caution.

• Start with a lower PSI (1500-2000) and gradually increase.
• Use a wide fan nozzle to avoid etching.
• Keep the nozzle moving and avoid lingering in one spot.
• A turbo nozzle is great for stubborn spots, but use it with caution.

Hope this helps! Happy cleaning!