If your house has an attached garage, consider adding a steel fire-safe door as a safety measure because it will prevent the spread of flames from the garage (where many fires originate) to the house. Choose one that is rated for at least 90 minutes, which means it can withstand the flame for 90 minutes. A fire-safe door come ready to install, prehung in its own steel jamb and is available in different styles and sizes.A carpenter will charge $230 to install a fire-safe door, or you can buy the unit for $185, and install it and save about 20 percent. Replacing the door is a doable project for someone with carpentry experience. You'll need basic carpentry tools, and an electric drill will come in handy.
Before installing the new door you have to remove the existing door along with the trim and jamb.
The door frame or jamb is made of pieces that you assemble so it's an easy installation. You join the head and side jamb pieces together, inserting tabs in side slots to create the steel frame, which you position in the rough opening. Secure it with screws, install the door on its hinges and attach the steel trim pieces to the jamb.