Abstract: A door is disclosed which is primarily intended for application as a door being resistant to fire.This door having a more particularly metal frame, whereby disposed on the door frame is a material which foams under the effect of an increased temperature. Said material is applied in the form of a strip in the rebate of the door frame. Further, said material can be protected by means of a cover being wider than the strip of said foamable material, whereby the projecting portions of the cover bear tightly against the frame. One projecting part of the cover is disposed in one of the rooms, and the other projecting portion in the other of the rooms separated from one another by the door.