Hi could you pls advise me, I’m living in a 4 in a block flat and all the flat doors opening to the close area are fd30, however due to sound problems my housing association has replaced the fd30 door for a 54mm thick door and a pine frame. Given all 54mm solid core doors seem to be fd60 doors should the frame be made of hardwood or given there only looking for the door to act as a 30min door dose the frame meet the correct regulations?

If the 54mm thick door is required to provide only thirty minutes fire separation performance, then a softwood frame would be acceptable provided that it meets the specification contained in the door leaf technical data sheet.