Compartmentalisation is one of the most important tools that a designer has to control fire and smoke spread in any building. A two way fire rated membrane (horizontal or vertical) system is engineered to prevent fire spread without consideration of from where the fire originates.
We refer to LAF’s Trimesh® System outlined in CSIRO’s FCO-0522 which represents a suspended lightweight construction system that can be used for erecting non-loadbearing elements such as mono or multilayered horizontal and vertical barriers as well as complementary structures such as risers dividing walls, internal curtain walls, acoustic and thermal insulation walls and floors. Typically this is a suspended ceiling element.
The Trimesh® construction can be supported from the concrete plats via fire engineered hanging rods with 100 x 100 mm steel plates secured with a double nut arrangement. A secondary sacrificial channel can be suspended below the LAF two way fire rated ceiling to carry all ducts, cable tray and other hydraulic services. A two way fire rated plenum, used to convey fresh air, can be fixed then. In a few cases instead of a foil vapour barrier, we have combined the Trimesh® panels with sheetmetal or board construction to ensure a smoother, always airtight and more aesthetical finish.
With most types of Bulkheads and Ceiling systems, it is imperative that the Fire Source be ascertained before a pertinent system can be designed. In the case of superimposed ceilings over fire isolated passageways and stairs, the Ceiling and/or Bulkhead will ideally need to prevent Fire from spreading into the passageway/stair rather than contain a fire within the compartment. The LAF Separating Construction System offers a ‘two way’ Fire Rating as is required over Fire Isolated Paths and/or Stairs.
LAF separating construction systems can also provide air-tight enclosures for high pressure return air shafts. They are self-supporting and provide protection from fire in either direction. This is a most convenient system when confronted with difficult access situations, such as upgrading walls with restricted access from both sides.
Services required to be attached/suspended from the LAF separating construction system, should be independently supported without reliance on the system itself. Support details should be carefully planned to ensure compliance with regulatory requirements.