Understanding Nominal Joint Width (Installed Width) And Actual Movement in U.L. Listings
Nominal Joint Width in U.L. listings refers to installed width. Nominal Joint width does not equal movement capability because the joint material can only move a percentage of its thickness. For example, systems that require fire caulk or spray can only move a percentage of their nominal joint width because they are limited by compressibility, elasticity or bond strength. To determine actual movement you must multiply nominal joint width by the percentage of compression and/or extension.
For illustration: A 1” nominal joint width with 25% compression has an actual deflection capability of only 1/4”.
The Fire Trak System, when installed at a nominal joint width of 1” has a full 100% movement in compression for a full 1” of deflection. By extension of track depth, the Fire Trak System can move 1” (100%) in both compression and extension for a combined range of movement of 2”.
The Fire Trak System is U.L. tested and listed at 1” and 3” nominal joint widths with 100% movement in both compression and extension for combined ranges of movement of 2” and 6”. The Fire Trak System can have any range of movement from 1” to 6” in 1/2” increments.
