Numbering System For Rated Wall & Partition Assemblies Found in UL Directory Volume Membrane Protection
Groups of Construction
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.