HappyP

Hi a couple of questions if anyone can help... I've seen a fire door with an intumescent strip on the door AND the frame (same door) does one need to be removed or are they ok to be left. Both are in the right place and I'm assuming one was just left in situ when the other was put on but just wondered if they would conflict if there was a fire? Also - do metal fire doors have to have strips and seals? Thanks to anyone who replies