On top of the Roof

Fire rated doors.  When the fire codes changed in the United States the fire department required all apartment doors, storage rooms in apartment buildings, boiler room doors, basically any room door inside a residential or commercial buildings to be rated at least 90 minutes. This means the door has to be able to withstand fire for 90 minutes before catching fire.  Recently the buildings department has been going around New York requiring building owners to install self closing fire rated doors for elevator machine rooms. The fire rated doors are usually made of at least a 18 gauge steel, with a solid wood core inside. The wood inside is usually treated with a fire retardant.  Usually an experience locksmith would replace an existing door with a fire rated door with an insert iron angle frame. Using an insert frame you avoid measuring the hinges off and insuring a smooth and easy installation.  Also the insert frame usually strengthens the existing frame.  Also when the existing frame has been damaged or worn out a locksmith should use an insert frame. There are times when locksmiths have used iron angle insert frames to strengthen existing wood frames.  I personally have installed insert frames and fire rated doors on many occasions to cover up damaged frames and also to strengthen existing frames. If you live in an apartment and would like to have your existing door upgraded definitely have your locksmith install a fire rated door with an insert angle frame, mortise lock, and preferably a tubular dead bolt.  There are buildings that still have old prewar style doors, I recommend having those doors replaced along with your other reconstruction of the apartment.