Door lining internal dimension

[fattony]

Hi

for a 610mm door what would the internal dimension of the door lining need to be, looking at a 762mm lining it measures 770mm so I’m assuming it needs to be 618mm but want to double check

thanks

 

[JobAndKnock]

In a fire door your gap around the door on the sides and at the top is normally 3mm, so a 610mm wide door needs a casing or lining 616mm wide internally (approx. 680mm externally allowing for a 32mm or 1-1/4in thick casing or lining)