I have a 3 storey house built around the year 2000. All internal doors in the house are the same. The doors are 44mm think with 3 hinges, feel heavy and have percos. I am quite sure that they are the original doors, so would have complied with the building regulations at the time the house was built. They do not have any intumescent strips. I plan to add intumescent strips to them. The door stops and frames seem to be the correct specification for a fire door. Do you think that I can just add intumescent strips to make them FD30? Or should I consider getting new doors? My intention is to ensure that the house has FD30 doors, but I wish to determine if these existing doors are suitable for this. I cannot find any labels nor plugs indicating their specification. Along the top of the doors it says, "DALE 90623", which is probably the manufactures code for the style. However I have been unable to determine anything else about the door. I would be grateful for any suggestions.
