Linda, I am not an expert on home repair of any kind, believe me, I read as much as possible before I tackle even what most think of as simple projects... but as a Respiratory Care Practitioner, I have seen folks who have had serious health problems related to molds and other contaminants which may be airborne. Fortunately for most people, those most affected are the ones who are in previously poor health. Another predisposing factor is asthma, certain allergies or emphysema. Legionnaires disease has been linked to airborne contaminants borne out of ventilation systems. I recommend a thorough repair of the areas allowing the moisture, then treat any areas of wallboard, carpet or wallpaper which may harbor the possible mold spores. Molds do not particularly enjoy light, lack of moisture, or ventilation. Have your Dad checked for any health problems by a physician immediately if he experiences any UNUSUAL symptoms, that is, other than those conditions which may be chronic for him. Also, advise the physician about the house if his conditions may be pulmonary related. I know this isn't alot of help... but the keyowrd is prevention. Good luck!