The answer to 'what causes skylight' is that skylights are installed in roofs to allow natural light to enter a room. Skylights are typically made of glass or plastic and can be fixed in place or designed to open and close. Skylights can be installed during the initial construction of a home or added later as a renovation project.
Skylights are a popular feature that can brighten up a room and reduce the need for artificial lighting. However, improper installation or damage to a skylight can lead to leaks and water damage. It's important to have skylights installed by a professional roofer to ensure they are properly sealed and flashed to prevent any issues.