Black Steel and Rockwool
The use of insulation materials for fire protection of ductwork
In conjunction with Firemac FM Fire Ducts
Firemac FM Fire Ducts that require thermal or acoustic insulation must be insulated with non-combustible insulation
material, e.g. a glass or rock mineral wool which is fitted over the Firemac FM Fabric. Class O or combustible acoustic
insulation is permitted if fitted inside the duct.
If insulation is required for the purposes of fire protection, Firemac's construction specification must be followed. The
complete duct system, including the design of the steel ductwork, the Firemac FM Fabric and the rock mineral wool, is
tested and approved as a complete system. If the fabric is not used this may affect the required specification for the
steel ductwork. For example, using the rock mineral wool alone may require thicker steel or more hangers.
If most of the duct run does not need insulation then it makes sense to make the complete run as an uninsulated
Firemac system, under controlled workshop conditions, and to apply the insulation on site in the limited areas
required. This cuts down on cost and space required.