Directories & Additional Information

Underwriters Laboratories
  • Underwriters Laboratories Fire Resistance Directory Volume 1 - Hourly ratings for Beams, Floors, Roofs, Columns, and Walls and Partitions
  • Underwriters Laboratories Fire Resistance Directory Volume 2 - Hourly ratings for Joint Systems and Through-Penetration Fire-Stop Systems
Systems & Products Directory
Numbering System For Rated Wall & Partition Assemblies Found in UL Directory Volume
Membrane Protection
Groups of Construction
300-399 400-499
Wall and Partition: U,V or W
Wood Stud Gypsum Board
Metal Stud Gypsum Board
A specific design number will specify the Assembly Rating and Finish Rating. The design will also list the specific components of the assembly (i.e. studs, wallboard, joints, batts and blankets) as well as the construction details for the assembly.
The wall, partition, floor/ceiling listed design is essential to follow because it is a tested design (assembly).
Example: A 1-hour-rated wall (fire barrier) is required. The construction type is wood frame or metal stud, and gypsum board is desired; the UL Design group to use is U300-U399 for wood and U400-U499 for metal stud.
Example UL Designs
These samples are to demonstrate the specific requirements for the wall construction.
  • U305 Design
    • Bearing wall rating - 1 hour
    • The gypsum board is specified by manufacturer and manufacturer's type
    • Nail size and installation is specified
  • U404 Design
    • Bearing wall rating - 1 and 2 hour
    • Non-bearing wall rating - 1 and 2 hour