Durasteel is a composite panel of fibre reinforced cement mechanically bonded to punched steel sheets on both surfaces It is classified as non-combustible in accordance with many national and international standards and is highly resistant to moisture even when saturated. It will not absorb combustible fluids and its tire resistant qualities are exceptional

Durasteel is highly impact and blast resistant,which enables it to withstand prolonged exposure to fire of the cellulosic,hydrocarbon or jet fire types. It can also withstand hose-stream actions and,because of its very low moisture absorption,it can be used externally and is not susceptible to the damage often caused by moisture during the early
stages of delivery and installation of the system, or by sprinkler actuator.

Durasteel is a fit and forget system,which requires virtually no maintenance.

Features/Advantages of Durasteel®

  • Strong
  • Impact resistant
  • Moisture resistant
  • Maintenance free
  • Requires no foundations
  • Space saving
  • Engineered for fast track construction
  • Flexible installation
  • Offers up to G hours fire protection
  • Lightweight
  • Employs only dry trade installation methods
  • Relocatable and suitable for retro-installation
  • Proven 40-year design life
  • Tested to Hose Stream ASTM E119 to 5-bar pressure
  • Tested to DIN 4102 to 4000J hard body impact after fire test
  • Ducting available in 1, 2, 3, or 4-sided configurations with internal or external flanges, with up to 4 hours fire resistance
  • Non-combustibility with zero spread of flame
  • Nui-luxic
  • Man-made mineral fibre-free
  • Modular or kit form construction
  • Loadbearing and non-loadbearing constructions
  • Resistant to the most onerous fire curves, e.g., Hydrocarbon, Jet fire, etc.

Typical Applications
Ventilation ducts:

  • Smoke extract ducts
  • Kitchen extract ducts
  • Cable protection ducts
  • Service ducts


  • Plenum chambers
  • Loadbearing ceiling
  • Membrane ceilings
  • Suspended ceilings
  • Lift or service shaft cappings


  • Partitions
  • Service shaft
  • Lift enclosures
  • Cavity barriers


  • Valve box enclosures
  • Switchgear enclosures
  • Ducts
  • Escape tunnels
  • Storage systems
  • Hatch covers
  • Fuel pipe protection

Introducing Durasteel

  • Moisture resistance
  • Impact resistance
  • “Walk-on” strength
  • Fire resistance up to 4 hours including insulation
  • Super-spanning capability
  • Pressure resistance
  • Demountable
  • Loadbearing systems available for up to 15 kN/m²
  • Hose stream resistant

Ceilings & Plenums
Intumex Durasteel° ceilings can be formed to fulfil a multitude of functions. Horizontal constructions can be used not only as traditional suspended and membrane ceiling constructions,but can also be used as plenums, single sided enclosures to cables and
services. Intumex Durasteel® ceilings can be designed as load bearing structures,and even
standard Durasteel® ceilings can be used as trafficable constructions.

Durasteel® horizontal barriers have been fully tested to the requirements of BS 476: Parts 21 and 22: 1987. These barriers can withstand fire exposure from above, below or above
AND below,dependent on the design and performance requirements.

The overall system design will depend on the performance characteristics,but typically would consist of Durasteel® panels.fixed to one of both sides of a steel supporting framework,with or without the cavity filled with rock wool.

Introducing Durasteel Ceilings & Plenums
Durasteels bad bearing ceilings can be constructed from simple readily available local materials.The fire performance of such systems can offer includes up to 240 minutes integrity and insulation, as well as bad bearing capacity,regardless of whether fire exposure is from above or below.

Depending on the load bearing requirement, it may be necessary to include additional, protected, steel support sections beneath the ceiling construction.

Depending on the insulation performance requirements, it may or may not be necessary to include additional cover fillets over the steel sections to retard the conduction of heat through the ceiling construction.

The detail below shows the construction with two cover fillets either side of the support framing.The number and overall thickness of the fillets is dependant on the Insulation performance required.

Durasteel Ceilings & Plenums Types of Application

Self- Supporting Membrane Ceiling With Supalux
Intumex Durastee® can be combined with Intumex Supalux® boards to provide a cost effective system, offering the same robustness and trafficable construction as the standard Durasteel construction,but with the one side clad with Supalux® to provide a more aesthetic appearance.

Durasteel® membrane ceilings can offer up to 240 minutes integrity and insulation.

Suspended Plenum Ceiling
Durasteel suspended ceiling con-structions can be used to act as Plenum chambers. Durasteel is capable of withstanding very high positive and negative pressures.Durasteel® systems fully comply with the air leakage rates of DW144.

Durasteel ceiling systems can cover extremely large spans, especially where internal hanger support systems are incorporated into the design. Please consult Intumex Asia Pacific for further details.Also see page 60.

Durasteel Ceilings & Plenums Types of Application

Self- Supporting Double Layer Membrane Ceiling
Similarly,double layer membrane ceiling systems can be constructed to cover large expanses with the introduction of additional hanger support systems. Inclusion of these additional supports can often allow a reduction in the dimensions of the support frame members,offering a lighter weight and more cost effective system.

Durasteel Ceilings & Plenums Construction Details
The below details depict methods of constructing membrane ceiling systems without recourse to additional hanger support members. The section shape,type and dimension of
the stool support structure is dependent on the span, the overall weight of the ceiling
construction, the required performance in terms of fire and under normal operating conditions.E.g. load bearing capacity.Please consult Intumex Asia Pacific for details.

Durasteel ceiling constructions can be used to create one,two or three sided enclosures. These can be used as plenums, services enclosures or to provide compartmentation.