Since mold thrives in damp environments, it is a very common problem for homes and businesses with leaks or water damage. It only takes mold around 24-48 hours to begin growing, and the longer you wait to seek repairs, the more likely you are to run into mildew or other fungi. Over time, the mold spores can cause a whole host of health problems such as: Stuffy nose Sore throat Skin rashes Allergic reactions Asthma attacks Coughing or wheezing