If your driveway, sidewalk or patio has gone from light gray to a dark green or black, you are not imagining it and you did not do anything wrong. Concrete in south Louisiana grows organic film faster than almost anywhere, and shaded concrete can turn in a single wet season. Here is what causes it and how it actually gets cleaned.
Why Louisiana concrete turns green
Concrete is porous, so it holds moisture, and our humidity keeps it damp. That damp surface feeds algae, mold and mildew, which spread as a green or black film. Shade makes it worse, which is why the north side of the house and the parts of the driveway under trees go first. Beyond looking bad, that film is genuinely slick when wet and becomes a slip hazard on walkways and entries.
Why a surface cleaner beats a bare wand
The difference between a clean job and a striped mess is the tool. A bare pressure wand cleans in a narrow fan, so it leaves zebra stripes where the passes overlap or miss. Flat concrete is cleaned with a surface cleaner, a round attachment that spreads even pressure across the whole width and leaves a uniform finish with no striping. Good crews also rinse the surrounding area so nothing dries dirty.
A treatment that keeps it clean longer
Because the green is organic, a good driveway cleaning does not stop at pressure. A post treatment that kills the remaining spores slows how fast the film comes back, so the concrete stays clean for months longer than a plain blast with water.
How often concrete needs it
Most Baton Rouge driveways need cleaning once a year, and shaded concrete in Central, Zachary and Denham Springs often needs it every six to nine months. Entries and pool decks that get foot traffic are worth doing the moment they feel slick, since that is a liability more than a looks issue.
Hydro Clean Maintenance Solutions cleans driveways, sidewalks, patios and pool decks across the Baton Rouge area with surface cleaners and a post treatment, so your concrete comes out even and stays clean. Call (225) 681-3639 or request a free estimate.