I've just got pulled into a job where the customer told me the job was fitting a door and frame, I asked if it was standard timber door and frame and they said yes.

I turn up and find out he has a fd30 for a fire exit door and frame to fit door both are 9inch to heigh, 

Am I right that it's still not possible to modify the door or frame in any way beyond manufacturing instructions.

I have for now re measure brick to brick so he can try to get a set to fit properly.

 

It's in a salon for the rear exit out onto carpark and the old frame and door are so rotten that it needs replacement asap

 

I am clued up for internal work on flats and domestic but commercial like this I would rather try to find out

If it is a fire exit door (i.e. leading directly to fresh air) then typically this would not need to be fire resistant so is there any reason why they've got a FD30 leaf and frame?

Unless it opens out on to an external escape route or external escape stairway in which case a fire door may be needed to protect occupants using the outside routes?

If it does need to be a fire resistant door, you are absolutely correct in saying that none of the door-set components can be adjusted unless it is completed in line with manufacturers instructions - otherwise the door-set is invalidated.

If its a commercial premises, there must be a fire risk assessment in place which would address this too.