Hi,
Thanks for your post. I am very concerned to hear about the work done to the fire doors fitted at your flat. The building owner and contractor 'may be' in very serious breach of the Fire Safety Order and you should seek formal advice from the local Fire Service.
If a fire breaks out while asleep the risk of death due to smoke inhalation is great. Therefore fire doors in this type of situation should have smoke seals fitted to the top and both long edges of the fire door or frame and they must be in constant contact with the door edges and frame when the door is closed. A self closer should be fitted.
At the bottom of the door, the maximum gap between the floor and the bottom edge of the door should be 3mm - YES 3mm !!!
That is about the thickness of a pound coin.
Ideally a drop down threshold seal should be fitted.
If you have fire and smoke resisting doors fitted at your flat building and the clearance between the floor and the bottom of the door has been increased by cutting or planing the door down as you say then the smoke protection offered has now been negated and should be put right without delay.
If I were resident in these flats I would take action without delay.
Regards, Neil Ashdown
Fire Door Inspection Scheme
London. WC1E 7BT