That white powder on your stucco isn't mold — it's minerals bleeding through the wall

When water soaks into concrete, block, or stucco, it dissolves naturally occurring salts inside the material. As that moisture migrates to the surface and evaporates in Florida's heat, it leaves the salts behind as a white, chalky or powdery crust. This process is called efflorescence, and it shows up on walls, foundations, driveways, and retaining walls — anywhere porous masonry gets repeatedly wet.

The tricky part is what not to do: blasting it off with a pressure washer forces more water into the already-saturated material and can accelerate the very cycle that's causing it. And since the salts are coming from inside the wall, wiping the surface clean without addressing the moisture source means it comes right back. The underlying cause — a drainage issue, a grading problem, or poor joint sealing — needs to be identified first.