Any chemicals or cleaning mix that help to clean dirty cement?

Scotts Outdoor Cleaner
Recently used this to clean up some mildew and my pathway to the front door. Requires some brushing, but works pretty well. Definitely not as effective as a power washer though.

Oxyclean or Scott’s as a prespray 15 mins before pressure washing has been effective for me.

I try to avoid anything that would kill the grass.

How do you mix the bleach ratio?

Mixed with water?

Spray and let sit?
Scrub?

Pre-wet your concrete, 50/50 water to bleach will do the trick on most algae. If you have some stubborn areas, up your percent. Scrubbing will only be needed in the worst areas.

They sell bleach in various concentrations. The 50/50 ratio is for the blue bottle of Clorox. If you buy a higher concentration bleach, dilute accordingly.

Add bleach to water, not the other way around. And don’t wear any clothing you like.

If bleach isn’t getting the stains up, you have oil or rust stains. Muriatic acid for the rust, any detergent for the oils.

Ha I was just looking at that last night. Someone brought up soft washing your roof, which I never heard of. This was one of the recommended chemicals. Seems pricey, but mostly good reviews.

Bubble juice from Walmart toy section.

My kid spilled a bubble machine in the driveway last year, and after the next rain, the spots the bubble juice had soaked in looked like freshly poured cement.

I use Clorox outdoor bleach. 1.4

I have a nice slope on my driveway so sometimes if it's raining hard enough I will poor outdoor bleach at the top and let the rain mix and do all the work on the green mildew.

In answer to The Boo, yes, I have used Wet and Forget and am very happy with the results. Spray it on and the green stuff goes away in a day or two. And not nasty to work with.