In the late 1970s, when the need for firestopping dynamic joints first emerged, it was the drywall manufacturers that answered the call and designed wall assemblies that could be tested per design standards found in ASTM E119 and UL-2079. At this time, the known non-combustible materials were drywall, mineral wool, steel framing, and spray-applied fireproofing, so naturally that’s what was used. Fifty-plus years later these materials are still the workhorse behind fire rated wall assemblies.
HW-D-0001 provided the first dynamic joint system. This system did not require any fire sealant or fire spray. However, it did require a unique wall assembly that utilized field cut drywall rips attached to a metal angle. The drywall rip and metal angle were placed over the finished drywall and joint as a way of protecting the open joint.