Fire doors are constructed from special materials specifically designed to help prevent the spread of fire. Various materials may be used to make different fire doors.
Ordinary glass may not be fire resistant, but tempered glass is. It is five times stronger and, most importantly, can withstand temperatures up to 204 degrees Celsius.
The mineral gypsum is used as a filler in fire doors because the reaction produced when it burns absorbs heat energy.
Steel, which is simply processed iron, melts at around 0-3.889 degrees Celsius.
Wood is often used as fuel for fire. But when used to make a well-designed timber fire door, it can delay the spread of fire and smoke for 30 to 60 minutes.
The mineral vermiculite has a unique property: When rapidly heated, it expands to up to 30 times its original thickness.