Fire rated plasterboard boxes and/or bulkheads are often specified to accommodate service penetrations below concrete slabs. However, design and construction methods are not well understood. Risky assumptions, and a poorly designed and constructed box or bulkhead, can lead to premature failure. It is important to get the detailing and installation right.

Winstone Wallboards recommends ‘universal’ lining systems such as GBUW and GBUC specifications for wall and ceiling applications respectively. These linings must be applied to a structurally adequate box or bulkhead frame. ‘Universal’ lining systems are designed to limit cavity temperature rise to approx. 300 degree C, to protect timber framing from char and light gauge steel from substantial strength loss. Specifications GBUW 15 to 180, and GBUC 15 to 120 ensure the specified FRR of a well-constructed box or bulkhead can be achieved. Figures 1 and 2 show the principles of constructing a fire rated box or bulkhead based on ‘universal’ specifications and GIB Fyreline® linings. Specific box or bulkhead framing layout can vary on-site depending on required dimensions.

Read more in the PDF below.