Yes — in Jacksonville's high-humidity climate, mold can establish in a Southside or Mandarin home from a slow plumbing drip, a failing HVAC condensate line, or a compromised window seal, none of which produce visible flooding. The warm, humid conditions inside wall cavities and under flooring provide everything mold needs to grow without any dramatic water event. A musty odor, unexplained allergy symptoms, or soft spots in flooring are common early signs that warrant a professional moisture inspection.