A DEM Fire guide to passive fire protection

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As a trusted family business, DEM Fire is committed to exceptional service for every customer. Our holistic approach to fire prevention includes solution design, system installation, asset management and fire compliance. And we have a specialist team of fire system experts in-house.

Our project team has expertise across all aspects of fire prevention design and installation, and our asset protection team monitors and tests installed fire system components, including passive fire protection.

Passive fire protection is a key element of structural fire protection. We explain here how passive fire protection works, and why it’s critical for building fire safety.

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What is passive?

Passive is the stuff that doesn’t make noise, doesn’t flash, doesn’t call the brigade and doesn’t squirt water. It does, however, work efficiently to help prevent the spread of fire through a structure.

Passive fire protection is one of the methods used to protect apartments, offices and other commercial spaces from fire.

It refers to the use of construction elements within a building that are designed to prevent or delay the spread of fire and/or smoke to other sections of the building. To achieve this, buildings are generally fire compartmentalised.

The purpose of passive fire protection is to limit the effects of fire within a building by acting as a barrier to fire and smoke or protecting structural components that may cause early collapse. This is achieved by incorporating fire-resistant rated elements in the construction and controlling the flammability of construction materials.

Generally, building managers would have some ‘baseline data’ which would indicate which areas of the building have been fire compartmentalised and therefore require regular inspection.

Passive fire vertical separation

Vertical separation

Buildings can be fire compartmentalised in a number of ways, including vertical separation. In this case, the building is sealed at floor level with a fire-rated floor (a concrete slab).

In addition, penetrations through this fire barrier floor need to be sealed with approved products, including:

  • mastic and fire pillows or fire mortar hob for cables
  • fire mortar or mastic for metal pipes
  • some form of intumescent fire collar for PVC and plastic pipes: to be installed on the underside of the slab (soffit) to crush and seal the plastic pipe penetration in a fire situation.

In order to meet the Building Code of Australia (BCA) guidelines, insulation may also need to be installed above the penetration to prevent radiant heat from transferring to the next level.

Passive fire horizontal separation

Horizontal separation

Where the building is separated into different fire compartments by fire-rated walls, it is known as horizontal separation.

One example is a warehouse with a separate office and a fire-rated wall between the two areas.

Shopping centres also generally have some form of separation between the retail areas and the car park, such as firewalls, fire doors or drenchers.

Highrise buildings may contain riser shafts for plumbing, electrical or mechanical cabling to run through the building. These riser shafts should have a fire-rated door and fire-rated walls on each side. As the riser is a separate fire compartment, the base level floor penetrations and all wall penetrations need to be sealed accordingly.

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Products for passive fire protection

DEM Fire can inspect your current passive fire protection as part of our asset management services. If we determine your passive protection is lacking, we may recommend fire stopping applications, which include:

  • Fire sealant
  • Graphite intumescent
  • Mastic sealant
  • Mortar
  • Fire batts
  • Fire pillows
  • Fire collars
  • Fire board
  • Vermiculite spray

DEM Fire has an award-winning team with the experience and depth of knowledge to deliver comprehensive fire protection solutions. For passive protection or any aspect of solution design, system installation, asset management or fire compliance, please contact us. Read more Fire Protection articles.

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