What rating do I need for a door between two townhomes? The situation is an opening in the basement. An exterior entrance leads into the basement down a stairwell. Then there is a "v" and you can turn left into one unit or right into the other unit. This space is covered by a "Bilco" type door.
The party wall is separated by two sheets of 5/8" sheetrock on both sides of the wall, extending up to the roof line, then out 4' in both directions.
The doors are separated by a "vestibule". There is a firewall between the two units. Do I need a 2 hour door on each unit, or a 90 minute door? The fire would have to go through a 90 minute door, then through another 90 minute door, so this is 3 hours, correct?