There are many reasons for the skylight to leak. Only an experienced professional should repair or diagnose the skylight, as it is dangerous to work in such elevated areas. Try to find out why the leak is happening before contacting the professional, so they have a baseline to go by. If this is not possible, the professional will review all of the possible reasons to determine why it is leaking or causing stains.
The most common reasons for leaking are roof issues, incorrect sealing, cracks, and inner condensation. Roof issues are the leading problems when it comes to the skylight. Moisture may be coming through broken roof shingles, which would make it drip down the skylight. If the skylight was not sealed properly, leaking can occur. If this is the case, a simple recaulking of the area could do the trick when it comes to repairing it. If there are cracks in the skylight, the whole thing should be replaced in order to stop the leak. Condensation on the inside of the ski light can also drip down from the skylight. The humid air comes in contact with the cool surface and results in water droplets. Crack a window or install a fan!
After taking care of the sky light itself, the area needs to be inspected for underlying damage. Where there is a leak of any kind, mold thrives! This is especially true in damp, moist, humid areas like bathrooms and attics. Repair and replace the drywall around the skylight when replacing the sky light itself to ensure that any affected wet areas are not left unattended for mold to grow. Inspect you home for any signs of mold growth- musty odor, staining, and allergy-like symptoms during the wrong seasons are all indicators that mold may be lurking in the shadows of the home! If left untreated, mold continues to multiply and can cause a great deal of damage to the home and to the health of the individuals living in it.
Contacting a professional is the best way to ensure that your skyligl is secure, and that your home is safe from mold.