Your concrete or brick surfaces should be cleaned routinely; mold, mildew, gum, and grease tend to build up over time leaving them unsightly and slippery. Rust and iron will also leave unattractive stains that can be a struggle to try and remove yourself.
We use professional techniques and equipment with heated water that will deep clean, returning it to like new. Many times, when done with store bought washers and by an untrained person, streaks are left to be seen and damage can be done to the property or yourself. Best to leave that dirty work to us.