[What certification is needed to be allowed to install fire doors?]

Thank you for info  most helpful

 

[What certification is needed to be allowed to install fire doors?]

I own a flat  on the 2nd floor which is the top floor at the end of the corridor , each floor has 4 flats, so 12 in total, it was built in the 1970 concrete construction.  My problem is  last owner fitted a standard front door, not a fire door arguing that  being the last flat  nobody  would be passing the front door in the event of a fire, which  turns out to be incorrect , BIG TIME

So I have some  questions

1, can i get a internal FD30 fire door fitted to the front door of the flat or does it need to a external FD30, whats the difference?

2.  i have a professional chippy that has fitted many fire doors before, if he adheres to the door manufactures fitting instructions can i legally get him to fit it.I judge him as competent to do the job,   He has good knowledge of smoke strips etc.

3  the original fire doors in the other flats fitted in the 1970's don't have self closers fitted ,should they have ? now 

 

Thanks in advance for your help.