120 minutes fire rated PROMATECT®-H Self-supporting duct - resisting fire from internal and external
- Assembling a self-supporting duct with a layer of PROMATECT®-H board, 25mm thick, to form an encasement by securing the board to the steel angle at corner joints and to the channel collar frame at the board joints using screws. Surround the encasement with mineral wool insulation, wrapping wire mesh to secure.