You should add 2 1 2 to the height of the actual door.
Fire door size chart.
The main difference between these and the standard uk sizes above are an increased door height of 2040mm and door thickness of 40mm.
Maximum doors size for fire ratings is influenced by but not limited to the following items.
Getting the rough opening size right the first time will save you from frustration when installing your doors.
Fire door standard sizes.
Chart of door ratings and labels.
Local codes should be reviewed but in general rated doors must be self closing and must have a positive latch.
Door size conversion chart.
All of the standard uk and metric door sizes are usually available as a fire door equivalent with the only difference being an increased door thickness of 45mm.
Just add 2 to the width of the actual door size.
There are also limits to the size of glazing in the door the width of gaps between door panels the height of the door under cut and the size of air transfer grilles.
Framing rough opening sizes are really quite simple.
Fire ratings for doors are influenced by but not limited to the following items.
Common options are 2040 x 526 626 726 826 926 x 40mm.
Steel gage of the door example.
This is because extra core component materials are required in the construction of the door to achieve its fire rating.
Metric sized internal doors are becoming increasingly popular and are now commonly used in scotland and europe.