Chemicals & mix · Field notes

Sodium hypochlorite and surfactants

The chemistry is what actually kills algae and mildew. Pressure only removes what you can already see.

Field guidance from our own work — not a scored test. We add full hands-on tests as we run them, with the conditions written down.

The active cleaner in most soft washing is sodium hypochlorite (the same family as pool chlorine), usually with a surfactant added so the mix clings to the surface long enough to work instead of running straight off.

The point is biological: black streaks on a roof, green film on a north wall, and mildew on a lanai are living growth. Killing it at the root is why a good soft wash lasts far longer than a plain water rinse.

Dilution and plant protection are the parts that separate a careful crew from a careless one. We pre-wet beds, meter the mix for the surface, and rinse after.

Related guide: Roof cleaning without pressure