I will install an EI30 inner door in the garage, between the garage and the small entrance hall leading up to the upper floor.
"FIRE DOOR SAFCO DOORS INNER DOOR EI30 9X21 RIGHT"
I note that the door has the specification "Max temperature difference per side: 5 degrees"
What does this really mean?
If I keep +10 degrees in the garage and +20 in the staircase and upstairs?
Currently, it is +20 in both the garage and the staircase, but for what reason should the temperature difference only be 5 degrees?
Condensation?
Compare with an 18-degree door for a heated shed, which according to the spec "withstands an 18-degree difference between outdoor and indoor air." If you then keep +10 degrees in the shed and it is -25 outside?