Posts Tagged ‘Intumescent Seals’

Passive Fire Protection

To better understand passive fire protection we need to firstly understand the concepts of “Compartmentalization” and “Flashover”.

Compartmentalization is the process of dividing large areas into smaller areas such as rooms within a level of a building. Each room may have a different function. You may have a plant room, an office space, a toilet area, and amenities area etc. In dividing large spaces into smaller areas we can then minimize the effects of one area on another area within the same space (e.g. two rooms on the one level of a building).

Flashover is the point at which there is the near simultaneous ignition of all combustible material in an enclosed area such as a room or the floor of a building (see the link at the end “Living Room Flashover). When certain materials are heated they release flammable gases. Flashover occurs when the majority of surfaces in a space are heated to the ignition temperature of the flammable gases. Flashover normally occurs at 500 °C (930 °F) for ordinary combustibles.[i]

If we look at a Time/Temperature curve[ii], you can see that for a fire to reach a temperature of 500 °C can take less than 10 minutes. From the “Living Room Flashover” video you can see that this occurs in the simulation in less than two minutes.

Passive fire protection measures ensure a building’s structure remains stable during fire, keep escape routes safe, limit the spread of fire, heat, and smoke from one compartment to another, so people have time to get out and fire officers have time to get in.[iii]

If we look at a room like a balloon, the objective of passive fire protection is to keep the air in the balloon for as long as possible. If we have a hole in the balloon the air escapes. If we have a hole in a compartment and there is a fire within the compartment, the fire can move from the compartment through the hole to an adjoining compartment and spread or alternatively the hole can provide additional oxygen to fuel the fire and accelerate the progression of the fire.

Plug up the holes, the obvious and the not so obvious

Passive fire protection is the process of “plugging up the holes”. For a room to be useful you have to be able to get in and out of it. For this to occur you have to create a hole in the wall into which you put a door so you can get into and out of the room.

Now we are in the room we need air so we run an air conditioning duct through the ceiling to the room. If we pump air into the room we have to allow air to leave the room so we leave a hole in the wall above the ceiling to allow the air to circulate through the room.

We want a drink so we go to the sink in the room and pour a glass of water. The pipes carrying the water and the waste from the sink go through the floor to the underside of the roof of the room below.

We plug our laptop into a power point. The cable for the power point runs through the wall and across the ceiling of a number of other rooms to the electrical distribution board.

So for our simple room we have a few holes which during normal activities are required to be there but in a fire can allow fire to spread quickly from one room to another if they are not adequately addressed;

  1. Doorway (Access and Egress Provisions)
  2. Air Conditioning Duct Work and Openings (Mechanical Services)
  3. Electrical Cabling through Walls and Ceilings (Electrical Services)
  4. Pipe Work through Floor Slabs (Hydraulic Services)

Passive fire protection is used to address these issues. The most obvious hole, the doorway, can be protected by the installation of a fire door with an automatic door closer so the door remains closed at all times and does not rely on people to close it.

The air condition supply ducts and return air ducts’/openings can be fitted with fire dampers which activate in a fire to close off the duct or opening and minimise the spread of fire and smoke. Fire dampers are not so obvious and are often installed incorrectly or not installed at all.

The walls can be fitted with fire resistant lining materials (such as fire rated wall sheeting) so a fire in the wall (possibly from electrical cabling) can be contained within the wall and not spread into the room. Fire rated pillows can also be installed in opening made through walls above the ceiling level to run cabling from one room to another.

Pipe work penetrating through the floor can be fitted with fire collars which act as a barrier around the pipe work to minimise the spread of fire through the floor into the ceiling of the room below.

The illustration below gives an idea about the various passive fire protection systems you may find in your facility.

Example of a fire and smoke compartment showing passive fire and smoke protection systems[iv]

 

 

Legend

  1. Fire and smoke barriers
  2. Structural fire-resistant elements–Beams, columns, trusses
  3. Fire-resistant doorsets
  4. Smoke doors
  5. Fire-resistant shutters
  6. Fire-resistant glazing
  7. Access panels and hatches
  8. Ducts and dampers
  9. Fire stopping of service penetration and control joints

Passive Fire Protection measures are intended to contain a fire in the fire compartment of origin, thus limiting the spread of fire and smoke for a limited period of time. This limited period of time is the time needed for people to safely evacuate the building. Fire protection is provided for life safety. Property and financial loss prevention is a by product of keeping people safe and having effective fire systems protecting our buildings.

Passive fire protection as with all fire protection systems and equipment should be installed, serviced and maintained regularly by trained, and where required, certified personnel.

To visualise the importance of passive fire protection the following photo[v] shows passive fire protection in action. The photo is an aerial photo of a brewery fire. You can clearly see how effective passive fire separation can be in protecting the lives of the people in the adjoining space and also the additional benefit of the protection of the structure of the adjoining space.

Looking for further information

The links below are provided purely for your convenience. They do not imply endorsement of or, association with any products, services, content, information or materials offered by or accessible to you at the target site.

http://www.pfpa.com.auPassive Fire Protection Alliance
http://www.nfpa.orgNational Fire Protection Association
http://irc.nrc-cnrc.gc.ca/Institute for Research in Construction/NRC
http://www.metacafe.com/watch/682670/from_living_room_to_inferno_in_under_2_minutes/-Living Room Flashover Video
http://www.firetactics.com/FLASHOVER.htmRapid Fire Progress & Flashover related fire development
http://afscc.org/Alliance for Fire & Smoke Containment & Control
http://www.eapfp.com/European Association for Passive Fire Protection
http://pfpf.org/Passive Fire Protection Federation (PFPF)
http://www.l-com.com/multimedia/video_clips/video.aspx?ID=13100Videos showing flammability of cables based on jacket rating
http://www.fpaa.com.auFire Protection Association of Australia
https://rfidams.wordpress.comPeter Mole’s Blog Page

References
[i] NFPA Fire Protection Handbook, 2-106
[iv] Australian Standard 1851-2005 Maintenance of Fire Protection Systems and Equipment (Page 163, Figure 17.1)
[v] Technical Guide TG-005 (Page 15), John Rakic
Disclaimer This article was written by Peter Mole General Manager at Taylors Doors and Frames and while every care has been taken in the compilation of this information and every attempt made to present up-to-date and accurate information, we cannot guarantee that inaccuracies will not occur. All copyright and trade marks accessible via the links in this article are owned by the respective website owners, or their licensors.

 

 

(the information in this blog entry relates to fire doors in Australia with relevant Australian Standards being AS1905.1, AS1530.4 and AS1851)

I was recently involved in a project where a service company inspected fire doors and subsequently informed the building owner that a substantial number of fire doors would have to be replaced due to non complying hardware being installed.

This is not necessarily an issue but from the client’s perspective, the building had been inspected and certified for over a decade without issue and only now was the compliance of the hardware raised as a possible issue.

To the client the recommendation of the service provider was questionable. Was the current report correct (and the last decade non compliant doors in situ) or, was the report incorrect? The answer to this question had enormous financial implications and as such the building owner sought further clarification.

I was contacted by the building owner to investigate the situation and provide advice based on what we could discover. Was the hardware compliant or not?

From initial investigations it was clearly evident that there was a lack of documentary evidence held by the building owner in relation to the originally installed fire doors. Having no door schedule, from a service perspective it would have been difficult if not impossible to adequately service the installed fire doors as the fire test report references for the installed fire doors was not known.

The majority of doors did however have compliance tags fitted to the door leaves identifying the manufacturer and from investigations in relation to the details on these tags documentary evidence was eventually located supporting the compliance of the original installation (this however is not always possible).

As a side issue, this investigation also outlined an issue whereby service companies in the past had installed upgrade seals to doorsets to rectify clearance issues. While a number of door types have been tested and approved for use of these seal systems, one door type identified at this site was found to have no such approvals in place (a door manufactured and tested prior to the invention of the upgrade seal system). As the seals had not been tested on the door type, the installation of the seals on these door types was in clear contradiction to the requirements of the Standards.

This revelation identified a clear issue in that the inspectors and repairers of these doors over the past decade did not have adequate knowledge of the approved items which could be fitted to the doorset installed, or if they did, disregarded the Standard requiring only tested and approved components be installed.

This failure has inadvertently left the building owner in a difficult position. They have unknowingly accepted repairs to their fire doors over time which are not compliant and have never been compliant.

The seals may in fact work on this type of door but under the Standards the seals have to be tested before this can be done. This testing confirms that by the inclusion of these seals on this type of door that the integrity of the door type is maintained and not diminished.

The final observation from this investigation was the fact that annual fire safety certificates (NSW regulatory requirement)  had been issued for the property year in year out even though non compliant issues in relation to the fire doors laid, and still lay, dormant.

From my investigations into this matter some concerning issues arise;

  • Lack of understanding as to why documentary evidence is so important
  • Availability of fire test approval documentation
  • Failure to properly identify, inspect and maintain fire resistant doorsets (a product no doubt of the licensing requirements, or lack there of in the case of fire doors

(While some States of Australia do have licensing requirements for individuals or companies working in the fire door industry, NSW does not currently have any requirement for licensing of individuals or companies involved in the certification, service or repair of fire doors. Courses are available through Registered Training Organizations but these courses are not mandatory under the current regulatory framework. The Fire Industry is working hard to see changes in this area. Lookup the Fire Protection Association of Australia if you want to know a little more about available training for people working in the fire door industry.)

  • Lack of knowledge in relation to approved hardware, seals, components etc which can be fitted to a particular type of fire resistant doorset
  • Lack of knowledge in relation to the general requirements of the Standards and how they apply to fire resistant doorsets, and components fitted to fire resistant doorsets
  • Lack of enforcement by regulatory authorities (NSW regulatory frame work, some other States in Australia are much more proactive in this regard), not in ensuring that certificates are provided but that they are a true and correct representation of the actual status of the installed fire resistant doorsets
  • Could insurers reduced or refused claims if issues such as these were identified following an event such as a fire where there was a loss of property or worse still a loss of life?

At the end of the day, essential services (such as fire doors, exit lighting, sprinklers, hose reels, smoke detectors etc)  are installed and maintained for the purpose of protecting life and minimizing property damage. Generally their importance is not recognized until they are needed and when they are needed, (if you are holding a fire hose or a fire extinguisher, if you are running to an exit in a smoke filled room, if you are going down the fire stairs past floors engulfed in fire) you should have the confidence that these services, installed for your protection, will in fact work and that you will be able to safely exit a building.


If you found this article useful or otherwise please provide comments or suggestions so I can improve on future posts.