Dividing a building into discrete fire compartments is by far one of the oldest forms of fire protection incorporated into buildings. By separating larger buildings into different fire resistant compartments, areas or cells, either to separate factories from warehouses, plant and equipment from common areas, to divide different levels of high rise buildings, or to separate one townhouse from another, we can effectively increase the life safety of the occupants of the building and limit the extent of the damage to the building and to the business after a serious fire.
Effective fire compartment barriers require all openings to be correctly sealed to maintain their fire integrity. This includes larger opening for doors, windows and the like, but just as importantly all openings for services.
The sealing of penetrations in fire resistant barriers is commonly referred to as “fire stopping”.
This Technical Guide (First Edition) has been prepared by JRAK Consulting and published by the Alliance for Fire and Smoke Containment (pfpa) to provide a basic overview on fire stopping of openings for services. These include fire stopping of penetrations for plumbing, electrical and mechanical service types.
The Guide provides specific information relating to fire stopping, covering briefly the Legislative requirements encompassing the Building Code of Australia, the relevant Australian Standards for design, installation, and maintenance. It also introduces the concept of a fire stopping system and discusses some generic types of fire stopping materials . It also includes some basic discussion on training, accreditation and licensing.
We would like to stress, that we have prepared this document in good faith to try and provide a starting point for end users, and the Product Guides or Find a Product Tables have been compiled from information provided by the manufacturers and suppliers themselves, and the readers are urged to contact the relevant manufacturers and suppliers and to do their own due diligence in relation to the products listed. We take no responsibility for any errors or omissions and we reserve the right to change this document without any notice.
Like any other publication produced by the Alliance for Fire & Smoke Containment, we would be happy to receive constructive criticism and feedback from readers so we can improve future versions.
Probably the most fundamental concept covering complying fire stopping; meaning fire stopping that complies with the Legislative requirements and be confidently certified, is that of a fire stopping system.
This translates into the concept of a fire resistant fire stopping system. The system includes the fire barrier type that is penetrated, (wall, floor or ceiling), the opening size, the service penetrating the opening, the products used to provide the fire stopping, the installation in accordance with the manufacturers instructions (based on the proprietary fire test information) and effective labelling as appropriate.
Figure 1 below, shows pictorially the concept of a fire stopping system, which comprises the complete assembly involving all the relevant components and of course contingent upon compliant installation.
Some of the more prevalent components that make up a fire stopping system shown in Figure 1 (below) are discussed in more detail on the following pages.
Fire Resistant Barrier
The first component we need to consider when looking at a total fire stopping system is the fire resistant barrier in which the penetration we are dealing with is located in. It must have a fire rating or Fire Resistance Level (FRL) in its own right.
Fire resistant barriers can be either horizontal, such as a floor slab, lightweight ceiling or a floor / ceiling system, vertical walls, which can be concrete, masonry (brick and mortar) or lightweight (plasterboard or other fire resistant board) construction, or a combination of horizontal and vertical, such as a bulkhead for example.
There are different configurations and types of fire resistant barriers and these in their own right should have been successfully fire tested to provide a known Fire Resistance Level (FRL) or “fire rating”.
Understanding that fire resistant barriers are fire tested to determine their fire ratings, it is also important that the fire resistant barrier type has also been fire tested in the appropriate configuration (as a horizontal and/
or a vertical barrier) inclusive of an opening incorporating the different service type(s) and with the proprietary type(s) of fire stopping products. This allows us to determine that the fire resistant barrier, opening, service(s) and fire stopping product(s), can operate together to resist the passage of hot flames and gases in the advent of a fire.
The design of penetration sealing systems needs to take into consideration the differential deflection in fire conditions of the fire resistant barrier, the service(s) and the fire stopping product(s), which if not correctly accounted for can lead to gaps forming, allowing the passage of flames and hot gases and resulting in premature failure during fire testing.
Most penetration sealing systems are not typically load bearing in their own right, therefore the fire resistant barrier must be adequately designed, fire tested and built in the field to accommodate the opening and not to transfer the load into the penetration sealing system itself. This for example might result in lintels in walls, additional reinforcing in floors, or additional and independent hanging systems in ceilings.
The overall size of the opening or penetration is an important consideration when looking at compliance or otherwise of a fire stopping system. The general rule of thumb is, “that we can create smaller openings than have been successfully fire tested”, and this includes height and/or width, or length and/or width, “but not bigger openings”. It is therefore important to know the geometry of the fire tested specimens and to compare these to those we are dealing with on site.
The diagrams below should provide additional guidance relating to opening sizes and allowable variations from what has been fire tested.
Service Penetration Types
Another important consideration when looking at compliance or otherwise of a fire stopping system is the type(s), quantity and proximity of services penetrations within the opening or penetration in question. The configuration of any support for the service(s) (or their absence) can also have an effect on the suitability or otherwise of the fire stopping system.
The different generic types of services are discussed below and the quantity and proximity of these respective services are discussed where appropriate.
Types of services
For the purposes of this Guide, the types of generic services that typically penetrate fire resisting barriers will be categorised as:
- Blank penetration seals
- Plumbing services
- Electrical services
- Mechanical services
- Control joints
Each type is discussed briefly below.
Blank penetration seals
The simplest openings to fire stop are those with no service penetrations contained within the opening. These blank openings or blank penetrations typically result from services that are relocated or where provision is being made for future services for example.
Plumbing services usually consist of plumbing related reticulation piping for items such as toilets (pans), sinks, vanities and the like.
In the main, plumbing pipes are either made from plastic or from a metallic or ductile material.
Plastic pipes include many different types of plastics, different internal or external diameters and different walls thicknesses, each attribute having a bearing on the effectiveness or otherwise of the fire stopping system. The most common type of plastic pipe is unplasticised polyvinyl chloride (uPVC), or just PVC for short, whilst others include HDPE, PP, PE, and ABS for example.
Plastic pipes, which melt in fires, create a special challenge for fire stopping, and typically, fire stopping systems incorporating intumescent (high expansion gap filling compounds) are required to effectively seal these penetrations during fire conditions. The most common means of fire stopping plastic pipe penetrations is by using a device known as an intumescent fire stop collar (or fire collar for short).
Metallic or ductile pipes, are less common in plumbing applications, but include steel, cast iron, copper and brass for example. Insulated or lagged metallic pipes, where acoustic or noise considerations are being catered for around the pipe in question, need to be treated differently than non-insulated or un-lagged pipes.
For both plastic and metallic or ductile pipe types, the pipe end conditions, governed by the use of the pipe and the ability or otherwise for hot gases to flow through the pipe prior to any fire related reactions (such as intumescence) occurring are also a very important consideration. For example the end conditions might be open or closed on one or both sides of the fire resistant barrier. Examples might include PVC pipes incorporating a waste trap, used for a stack at the top of a building, or used for a stormwater pipe. The waste trap, as it has water in it to stop odours in non-fire mode would be considered a closed end condition. The stack and storm water pipes would be considered open end conditions.
Quantity and proximity of adjacent pipes
An opening or penetration with a single pipe penetration is the simplest and easiest to seal effectively against the passage of fire. Openings with multiple pipes, are more complicated, and the quantity and proximity between adjacent pipes are important factors to consider when assessing compliance of a proposed fire stopping penetration. The allowable configuration depends on the type of pipes and of course the type and nature of the fire stopping product(s). The allowable configuration(s) will of course be governed by the fire testing performed and will be proprietary in nature; that is they will vary by supplier and product type. (See Sections below on fire test data and manufacturer’s instructions).
Electrical services are those which transmit electrical power (current) and any associated reticulation supporting structures. These translate in layman’s terms to cables, cable trays and cable trunking.
Cables themselves consist of a metallic core, (the current carrying medium), and an insulating or protective sheathing (casing). The core is more often than not made from copper whilst the sheathing is typically made of a plastic material. Just like plastic and metallic or ductile pipes discussed above, there are many different configurations of both core types and sheathing types, which do have a bearing on the effectiveness or otherwise of the fire stopping system.
It is typical to find multiple cables, clustered or bunched together, being reticulated through a common opening or penetration.
The type or types of cables, their quantity and their proximity to each other, taking into consideration the opening size discussed in the previous section, are the important elements when assessing compliance or otherwise of an overall electrical fire stopping system.
It is not unusual for multiple cables to be routed or carried and supported / fixed onto a cable tray. A cable tray is typically made from steel and the size and support of the cable tray are factors which need to be assessed when considering compliance or otherwise of the overall electrical fire stopping system.
Electrical services (continued)
Lighting in fire resistant ceilings
When fire resistant (incipient fire) ceiling incorporate light fittings, these need to be effectively fire stopped. There are a number of methods of doing this including building fire resistant boxes over fluorescent tube type lighting or using proprietary intumescent down light covers.
Electrical switch boxes
Switch boxes position back-to-back in fire resistant and lightweight (plasterboard walls) are required to be proprietary systems, which essentially consist of a conventional electrical switch box incorporating intumescent materials inside the box.
Electrical services (continued)
Specialist coatings are used to protect against serious spread of fire along longer runs of multiple cables. These coatings can be either intumescent or ablative, both having different performance and operational characteristics. Typically cable coating is used in larger factories and more industrial applications, as opposed to conventional buildings, where insurance requirements stipulate the need to minimise fire spread and reduce the down-time in the advent of a serious fire outbreak.
Mechanical services for the purposes of this Guide will include services for either fire services or for Heating, Ventilation and/or Air Conditioning services; the latter which is commonly abbreviated as HVAC.
Fire stopping requirements of openings or breaches in fire resistant barriers by fire related services in the main are to cater for the reticulation for a sprinkler, hydrant or hose reel system. In this case the reticulation of these systems is by way of piping which is either metallic or ductile pipe, or, in some special cases, plastic (orange CPVC) pipe. Pipes were covered earlier in the plumbing services sub section.
HVAC services typically form openings or breaches in fire resistant barriers by way of ducting or other openings for the transfer of natural, heated or chilled air. They may also include piping for refrigerants. Ducting is typically made from sheet metal but in recent times, there has been an increased use of proprietary and fire retardant plastic ducting. Fire dampers are typically used to effectively seal against the passage of fire through ducted openings. The opening within the fire resistant barrier and around the perimeter of a fire damper is an area where many breaches of the effectiveness of fire compartments are often found in audits of existing buildings. This in the main is probably due to (for example) the ineffective coordination of trades, namely the general building and mechanical services contractor and the absence of a specialist sub contractor engaged to do the fire stopping of the fire dampers.
Fire resistant compartments or buildings will typically incorporate transitions between floors and walls, adjacent walls and other fire resistant barrier intersections. There are also times where joints are designed and incorporated into discrete and usually longer or wider fire resistant barriers. These transitions and joints are designed to cater for building movement, and to avoid the transfer of loads during heating and cooling of the building, into the elements themselves. The absence of, or poorly designed joints, will typically manifest themselves as unsightly and unwanted structural cracking.
The common term for these transitions and joints are movement joints or control joints. They may also be referred to as linear gap seals as their length is many orders of magnitude bigger than their width or depth.
Fire sealing systems for control joints must of course be able to cater for movement throughout their design life and also provide effective fire stopping qualities if and when required.
The fire resistant barrier type(s), the orientation of the control joint, (vertical or horizontal), the joint width and length and of course the movement requirements are important design attributes when assessing compliance or otherwise of the overall control joint system.
Fire Stopping Products
There are many different fire stopping product types available to cater for the many different penetration sealing configurations that we encounter in buildings.
The type of product(s) used is obviously an important element of a total fire safety system.
For the purposes of this Guide, the generic types of fire stopping products, each of which will be discussed in more details to follow, are:
- Fire Collars
- Fire Dampers
- Larger Opening Barriers
- Control joint materials
- Other Fire-Stopping Products
Sealants (caulks) are compounds typically applied by caulking from a plastic cartridge, sausage or bulk container into an opening by way of a caulking (sealant) gun.
They come in different chemical compositions consisting of the following more common generic types:
- Acrylic (water based or latex)
- Hybrids of above
Many of the sealants used for fire stopping purposes include intumescent additives which allow them to expand to many times their original volume during fire conditions (exposure to extreme heat) which can be, but is not a mandatory, design attribute.
The different generic types of sealants are used depending on many different factors which include but are not limited to:
- Movement capabilities
- Tack free time
- Adhesion to substrates
- Requirement for surface preparation
- Resistance to water
- Resistance to UV
- Design life
- Ease of cleaning of equipment after use
Putties are not widely used in Australasia, but are a mouldable compound which can be pressed into openings around services or to fill gaps. Some putties can be reused when cables or other services are re-routed.
Mortars are powders which are mixed with water to form a compound which can be poured or trowelled into an opening and which set to form a homogeneous and usually lightweight barrier.
They are similar to concrete, except concrete will usually crack, fissure and/or spall in fire conditions, whereas fire resistant mortars do not.
Fire resistant mortars are usually much lighter when cured than conventional concrete and can be readily drilled through to form openings for additional cables or other penetrations over the life of the opening. They do not typically require any additional steel reinforcing and are not typically load bearing.
Many proprietary fire resistant mortars have red or blue die additives to assist with their recognition as a fire resistant material in the field. This is similar to the coloured variants of fire resistant plasterboard and other building boards and this trend is encouraged.
Fire resistant pillows were originally developed as a temporary form of fire stopping used extensively in telephone exchanges during construction. They consist of a similar construction as a conventional pillow we sleep on; that is an outer covering and an infill material.
The conventional fire pillow consists of a fire retardant cotton cover (again typically coloured for ease of recognition), with a mineral fibre infill material. These pillows are required to be packed firmly into openings to ensure no gaps are present to allow the passage of flames and hot gases. They are often used in conjunction with sealants to ensure that the integrity of an opening is maintained.
In more recent times there has been the introduction of water resistant casings and intumescent pillow infill materials, arguably making a more versatile and higher performance product and negating the need for using sealants as part of the system.
The use of fire resistant pillows is far too prevalent and many designers and facility managers prefer a more robust and permanent form of fire stopping product.
Fire collars, often referred to as “fire stop” or “fire choke” collars, are devices used to provide effective fire stopping for plastic pipes.
They typically consist of a steel or plastic canister, filled with a predetermined amount of intumescent (expanding material upon exposure to excessive heat) material.
During a fire scenario, as the plastic pipe begins to soften, the intumescent material expands to many times its original volume, helping crush the plastic pipe and fill the void, providing an effective seal against the passage of flames and hot gases.
Traditionally fire collars for use on PVC pipes were supplied in size increments to match the common pipe sizes, namely 40, 50, 65, 80, 100 and in some cases 150mm nominal diameter.
In recent times, to cater for other plastic pipes sizes, where the outer diameter of the plastic pipe varies, and to reduce model numbers and stock holdings, many proprietary fire collars can be used on more than one size and type of plastic pipe.
Fire collars designs consist of the following generic types:
- Cast in situ floor slab collars
- Retrofit or surface mounted collars
- Wall collars
- Ceiling collars
Cast in situ floor slab collars
These are nailed or fixed to the formwork and integrated within the steel reinforcing, prior to pouring of a concrete floor slab in a multi-storey building. They conventionally consisted of a robust, spun metal canister or casing, but recent advances in plastic technology and the cost competitiveness of the fire collar market has seen a transition in Australasia to plastic canisters.
The cast-in situ fire collar reduces the need for time consuming and expensive concrete core hole drilling by helping form an opening in the floor slab for the plastic pipe to be quickly and easily reticulated.
Some cast in situ collars can be difficult to identify or verify in situ during subsequent maintenance or inspection regimes.
Fire collars (continued)
Retrofit or surface mounted collars
These are usually fixed to the underside (soffit) of a floor slab or to both sides of a wall, after the plastic pipe has been reticulated through the fire resistant barrier.
Retrofit collars are easy to identify during subsequent maintenance or inspection regimes.
Walls collars are designed especially for vertical fire resisting barriers (walls). They are typically a canister that is built into or fits within a cavity in the wall, encapsulating the PVC pipe. Those made from plastic canisters typically require a metal sleeve when used in lightweight (plasterboard) walls.
Ceiling collars are collars fire tested and used for breaches in fire resistant ceilings where special temperature rise requirements (incipient spread of fire requirements) are called for in the Building Code of Australia.
Wraps are effectively fire collars without the outer casings / canisters, typically consisting of pre-manufactured quantity of intumescent material. As there is no canister, they are typically limited to concrete or masonry openings, where the fire resistant barrier provides the necessary constraints to limit the intumescent expanding anywhere except into the opening as the pipe softens.
Fire dampers are devices used specifically for fire stopping where ducts penetrate through fire resisting barriers. They are also used where non-ducted openings are provided for ventilation or for pressure relief, but in this instance a better term may be a fire resistant air transfer grille.
Mechanical dampers (gravity type)
The conventional fire damper is a gravity mechanical device consisting of either a metal curtain / shutter or a pivoted metal blade or flap, which is held in the open position by a fusible link (device typically containing a solder seal designed to melt and release upon application of heat) which initiates the closing of the opening in a duct (using gravity) during a fire scenario and provides a barrier to the passage of hot flames and gases.
Due to the nature of mechanical fire dampers and the moving parts in particular, it is important that adequate provisions within the fire damper assembly and around its perimeter within the penetration (opening in the fire resistant barrier) are incorporated to allow for the effective operation.
As mechanical fire dampers consist predominately of sheet metal, they provide little resistance to the conduction of heat or radiant heat flux through their curtain, shutter, blade(s) or flap during fire conditions.
Mechanical dampers (motorised type)
For special applications, such as zone pressurisation systems for example, motorised mechanical fire dampers are necessary.
Mechanical dampers (motorised type)
For special applications, such as zone pressurisation systems for example, motorised mechanical fire dampers are necessary.
Fire dampers (continued)
(Floor) Slab dampers
These are mechanical fire dampers designed for use in horizontal applications, where gravity closure will not occur. They include spring assisted closure mechanisms.
These dampers incorporate intumescent slats, contained in the air stream which swell up and close of the duct opening in the advent of a fire.
They do not include any moving / rotating parts such as springs, and depending on the proprietary nature of their design, can provide both resistance to the conduction of heat and radiant heat flux through the opening after closure
Combined mechanical and intumescent dampers
Most recent development have seen some hybrid mechanical and intumescent dampers, predominately to try and eliminate the intumescent slats in the air stream or opening within the duct, which can result in additional pressure drops and are perceived to be areas for collection of dust and lint.
Air transfer grilles
As discussed above these are essentially fire resistant grilles, incorporated into fire resistant walls for example, to provide functions such as natural ventilation or pressure relief.
Larger opening barriers
This category has been created to cater for materials used to fill large openings. These products are typically used to reduce the need to try and extend or build new infill parts to existing fire resistant barriers and/or to allow for the provision of a large quantity of service penetrations. They are used in conjunction with other fire stopping products, especially where the services breach the opening (for example sealants, fire collars and fire dampers might be used in addition to the larger opening barrier itself).
These products usually consist of a semi rigid or rigid board like materials however mortar and pillows are also used for fire stopping some larger openings.
Some examples include:
- Composite boards
- Fire resistant and non combustible boards
- Coated mineral fibre batts
These are special and proprietary boards, consisting of steel reinforced intumescent sheet material, often with sheet metal or heavy gauge foil backing materials. These are a means of filling larger openings in fire resistant barriers.
Fire resistant and non combustible boards
Board materials, which are relatively light and easy to cut and fix, such as Calcium Silicate technology are a means of filling larger openings in fire resistant barriers.
Coated mineral fibre batts
Mineral fibre batts (slabs), pre-painted (or painted in situ) with an intumescent coating are a means of filling larger openings in fire resistant barriers.
Control joint materials.
Materials used to provide effective fire sealing between transitions and movement joints discussed earlier are referred to here as control joint materials.
The type of material(s) depends on the fire resistant barrier type, size (width) of the joint and the movement capabilities.
Some generic types include:
- Deflection heads
- Fire resistant foams
- Composite foam & intumescent strip materials
- Proprietary joint systems
Discussed previously, but typically limited to a maximum joint width of 50mm and where modest movement is expected. These are used in conjunction with a non-rated backer rod material, such as open call polyethylene foam for example, which allow the depth of the sealant to be controlled.
These are a special configuration for the deflection head or movement joint (deflection head) required at the top of fire resistant and lightweight plasterboard (or other fire resistant board) walls where they meet a fire resistant floor slab.
These typically consist of a roll formed steel header track, with floating vertical studs, free to slide inside the header track, used in conjunction with fire resistant sealant.
A fire rated plasterboard wall deflection head fire stopping system
Fire resistant foams
These are specially formulated / modified foams which are fitted into linear gaps under compression and provide a fire rating in their own right. They may be used in conjunction with standard non rated sealant in some instances.
Control joint materials (continued)
Composite foam & intumescent strip materials
Composite foam & intumescent strip materials are used for large gaps and high movement joints. These can cater for gaps as big as 200mm wide.
Proprietary joint systems
Proprietary fire resistant joint systems exist for very large joints, with excessive movement including those for seismic areas.
Industrial fire stopping products
In the main, this Technical Guide deals with Commercial building types which are governed by the Building Code of Australia and all fire testing as described in detail in this Guide is conducted to AS1530 Part 4 from which an FRL (fire rating) is deduced.
For industrial facilities, such as oil refineries, steel mills and the like, depending on the insurance underwriter, most of these facilities will require different fire testing requirements and in many cases products listed by independent third party certification schemes, where ongoing factory audit are conducted where the products in question are manufactured.
FM approved products
The largest underwriter is Factory Mutual Corporation, who use their own fire testing procedures and also have their own listing agency. Products listed by Factory Mutual bear a FM Approved label.
UL approved products
Underwriter Laboratory is another organisation that has fire test procedures and a third party listing and labelling service.
Marine fire stopping products
Fire stopping products used on ships require special approvals from approved shipping authorise such as the US Coast Guard, Lloyds, DNV and others.
The products typically require increased resistance to water and against corrosion from salt water, but are tested to similar fire testing regimes to our own AS1530 Part 4.
Fire test data & AS4072/1 compliance
Standard fire test
The fire test method used here locally in both Australia and New Zealand is
AS1530 Part 4. This test method follows the basic principles of International Standard ISO834 Part 1.
Essentially the fire testing consists of building and mounting a representative specimen (or prototype assembly) onto a fire test furnace and burning the assembly against standardised time versus temperature criteria and with given pressure differential conditions across the assembly.
Measurement are taken to determine the time taken to exceed specified criteria for integrity, insulation and radiation as applicable from which fire ratings can be determined for compliance against Building Codes in Australia and New Zealand.
Fire stopping ’product’ Standard
It is not practical to fire test all the different configurations of service penetrations, and based on experience and sound logic, Australian Standard AS4072 Part 1 (Components for the protection of openings in fire-resistant separating elements – Service penetrations and control joints), provides some standard fire test configurations for electrical & communication cable penetrations, and metallic pipe penetrations. After successfully fire testing these standard configurations a range of allowable cable and metal pipe types are automatically approved. The Standard also provides design guidance, advice relating to installation, labelling and certification, as well as some rules relating to variations from fire tested specimens by way of laboratory technical assessments and/or formal letters of opinion.
Field of application for fire stopping products
The culmination of a manufacturer’s fire test reports and technical assessments / formal letters of opinions make up a proprietary field of application for a given fire stopping product. This field of application or scope of use for a given fire stopping product is then translated into manufacturer’s installation instructions for use in the field by competently trained installation personnel.
As discussed above, the field of application for a given and proprietary fire stopping product, is communicated into “dos and don’ts” by way of written manufacturer’s or supplier’s installation instructions. These typically include photographs or drawings to demonstrate the correct criteria for incorporating the fire stopping product in question into an approved fire stopping system.
Technical data sheets usually compliment the installation instructions and together this essential documentation must communicate important limitations relating to the fire stopping products such as:
- Fire resistant barrier types
- Maximum opening sizes
- Compatible penetrating services
- Surface or other preparation
- Fixing details
- Other important characteristics
Labelling & Paperwork
Where practical, all fire stopping system should be labelled for identification purposes to assist with ongoing maintenance (ongoing inspection and testing as appropriate). Although the requirements in AS4072 Part 1 are only contained in an informative Appendix, it is highly recommended that fire stopping systems are labelled.
To assist with certification and to provide a suitable platform for subsequent maintenance and evidence of compliance schedule should be provided by the installation companies at the time fire stopping systems are employed into buildings. These would be accompanied or reference fire compartment drawings and each penetration or cluster of services should have a unique identification number.
The evidence of compliance certificate, provided to certify the works should be accompanies with the detailed schedules listed above.
It might sound obvious but an important element of a fire stopping system is good workmanship. This can be translated into competent installers with adequate training, knowledge of the fire stopping product and fire stopping systems in question.
In some States and Territories, competencies translate in formal accreditation and licensing requirements.
Australasian Regulatory Requirements
Building Code of Australia
In each State & Territory of Australia, the Technical Provisions relating to Building Control are contained within the Building Code of Australia, commonly referred to as the BCA.
The BCA divides building into Classes, which relate to the use of the Building, and for each building Class, the Type of Construction is determined from the rise in storeys for the building in question. For a given Class, and construction Type, (eg Class 2, Type A Construction), the BCA in the deemed-to-satisfy or prescriptive provisions, provides the relevant Fire Resistance Level (FRL) or “fire rating” for different compartment barriers.
Building Code of New Zealand
The New Zealand Building Code (NZBC) works in much the same manner as the BCA using Purpose Groups in lieu of Classes.
The BCA uses Fire Resistance Levels (FRLs) to nominate the required fire rating for different fire resistant barriers within a given fire compartment.
The required Fire Resistance Level, (FRL) for a specific fire resistant barrier, in which an opening or penetration exists, with and without multiple service penetrations, is determined in accordance with Section C of the Building Code of Australia (BCA).
The BCA definition of an FRL is as follows: Due to the fact that most penetration sealing systems are not structural elements, (they are not designed and should not carry any structural building loads), these penetrations are not required to have a rating for structural adequacy and this part of the FRL is usually designated with a dash (“-“).
The BCA also provides some dispensation for insulation, which is the non-exposed side temperature rise, allowing some penetrations not to require an insulation part of the required FRL either (eg. Wall mounted fire dampers).
Australian Standard – AS 4072 Part 1
The “Fire stopping code” or the “Penetration Standard” as it is often refereed to is in fact Australian Standard AS4072 Part 1.
This is effectively the back-bone document of the fire stopping industry, of course along with AS1851 for maintenance of fire stopping systems.
The Scope of this Standards is:
AS4072 Part 1 is a primary reference Standard within the Building Code of Australia. The BCA requires all openings to be protected by a fire stopping systems complying with BCA Clause C3.15 which requires fire testing to AS1530 Part 4 and AS4072 Part 1 compliance.
As discussed earlier, AS4072 Part 1 provides relevant information pertaining to the design of fire stopping systems, stipulating requirements for movement and serviceability in particular, guidance relating to acceptable variations from fire tested specimens, installation requirements, requirements for marking or labelling and relevant documentation used for certification purposes.
Anyone working with fire stopping systems must have a thorough understanding of both this Standard and should own a current copy of the Standard.
Obviously in a short form Guide like this we cannot provide any detailed information here regarding AS 4072 Part 1.
Maintenance of fire stopping systems
Although compared to many other items of fire safety equipment, Passive Fire Protection products (fire stopping systems) are relatively unseen and often unthought of (even forgotten), they do require regular inspection and testing, adjustment and lubrication of any moving parts and the like. These items are typically referred to as maintenance and are conducted to ensure that when there is a real fire, the fire stopping barriers, complete with all openings / service penetrations, will have the best possible chance of avoiding fire spread as per their intended design function.
Although the Building Code of Australia does not call up Australian Standard, AS1851, this Standard is typically called up by other means and in most cases provides the relevant frequency and inspection and testing schedules for fire stopping systems.
Smoke leakage through fire resistant barriers
It is a common misconception that an effective fire resistant barrier will stop both flame spread and also the spread of smoke.
It is important to recognise, that fire resisting barriers do not have any tangible and quantified smoke (leakage) containment properties. Many fire resisting barriers, by way of the fire doors and many of the fire stopping systems (fire dampers, fire collars and other fire stopping products) will not provide effective smoke containment properties and may result in untenable environments for occupants trying to escape in a fire, and/or might lead to excessive smoke damage to buildings when fires occur.
There are different test methods, such as AS/ NZS1530 Part 7 that deal specifically with smoke leakage capabilities of assemblies.
At the time of writing there is currently quite a lot of discussion relating to the smoke leakage through penetration seals (fire collars in particular) and Australian Standards are convening with the Australian Building Codes Board to address whether we need to tighten up the requirements of the Building Code of Australia and further develop current and other Australian Standards dealing specifically with containment of smoke.
Training, Accreditation and Licensing
As we discussed above, fire stopping systems are complete assemblies and those people who install and / or carry out maintenance (service) of openings in fire resistant barriers, need to have a good understanding of all the requirements relating to fire stopping.
In many ways it is surprising that those who work with Passive Fire Protection Equipment and Systems, which as we know are important items for safety of occupants and protection of property and business in the main, do not have to have a specific trade or qualification to work in this specialised area.
Things are starting to change, but the changes are very much at a Regional State or Territory level, underpinned by National Competency based Training materials in this area.
We will not discuss the specific competencies in any detail here except to say as part of the initiatives supported by the Alliance for Fire and Smoke Containment, (PFPA) Accredifire plans to deliver training and provide accreditation for installers and service personnel who maintain Passive Fire Protection Equipment and Systems.
Visit the Accredifire web site to see what training courses are being held in your State or Territory, phone us on (02) 9416 0451 for a friendly chat, or email your questions to [email protected]