Structural steel members penetrating a fire rated wall system must be treated in the same manner as any other service penetration and appropriately sealed to maintain the fire resistance rating of the wall system. 

In response to customer feedback, Winstone Wallboards has recently completed additional testing on structural steel penetrations without clad-backs, hollow structural steel penetrations, and threaded reinforcing bar penetrations. 

The following details have been newly introduced or updated and are now included in the ‘GIB® Fire Rated Systems Supplement, May 2026’, superseding pages 130 and 131 of the ‘GIB® Fire Rated Systems, 2024’ manual. These details are supported by the BRANZ Fire Assessment Report FC16525-01-2. 

Each detail includes specific installation requirements, dimensional limitations, and applicable fire resistance ratings, all of which must be satisfied. It is essential that the penetration design ensures the steel element does not transfer fire-induced loads onto the wall system.  

CAD files for the above details are available on our website.