For a fire-resistance rating of 3 hours, what is the recommended rating for the door assembly?

The recommended fire-resistance rating for a door assembly that is part of a fire-rated wall with a 3-hour fire-resistance rating is typically equal to or greater than the rating of the wall itself. Therefore, for a wall with a 3-hour rating, it is appropriate to have the door assembly also rated for 3 hours.

However, it's important to note that door assemblies are often rated slightly less than the wall’s rating in practice, depending on specific building codes and the assembly configuration. In many situations, fire door assemblies rated at 2-hours are commonly accepted if they meet additional testing and performance criteria, but for full compliance with a 3-hour wall assembly, the most conservative and compliant approach would be to have a 3-hour rated door.

Choosing a door with a 2-hour rating may not provide adequate resistance in all jurisdictions or situations, particularly in instances where the door is expected to perform as well as the wall in case of fire. Therefore, while a 2-hour rating may be considered acceptable in some cases, the direct recommendation aligns with a 3-hour rated door assembly for maximum safety and compliance.