Dili kaha maayu nga butangan nila ug clear glass window ang mga pultahan or encase the paintings on the ceiling with glass to preserve it from pollutants such as smoke from the candles, dust and moisture.
im not sure kung ok ba siya kay kung butangan siya ug enclosure it will trap pollutants/dust and other toxic fumes man gud. As I know, works of arts should have a controlled environment with a regulated atmosphere. That's why important historical pieces are properly sealed with nitrogen gas as to slowdown the breakdown of the material caused by acids and other micro contaminants in the air. Also kung mag glass mo grabe and maintainance niya. Anyway these people knows better how to do it and also capable of restoring them.