In most countries and organisations, the term “fire stopping” refers to a system of penetration seal applications that is usually an integral component of a larger passive fire protection design. Effective fire stopping plays a vital role maintaining the functional integrity of a fire compartment, within walls, ceilings or floors and in conjunction with other passive fire protection applications employed under the overall principles of modern fire compartmentation.
The diversity of fire stopping products now available suit a wide range of building designs, penetrations and other functional openings. These include fire resistant collars for pipe and other service penetrations, and various penetration seals for floors, walls and partitions. Most modern fire stopping systems are made of sealant, mortar, cement and other tested and proven intumescent components.
All too often, however, particularly when it comes to actual application, proven fire stopping systems in a building are either taken lightly or overlooked, negating the crucial role fire stopping plays in the event of fire.
Determining the correct fire stopping systems to be used in any given application is rarely easy, especially in view of the architectural and engineering complexities of the modern built environment. Many factors have direct and indirect impact on the decision making process. These include but are not limited to the complexities of design and required build quality of the structure to be protected, likely building usage trends, cost and design considerations, overall and specific awareness of the importance of fire stopping, regulatory environment and building code requirements, and even local approval and enforcement in the local areas surrounding the proposed application.
The principal reasons behind the application of fire stopping solutions inevitably run parallel to the application of other and even more holistic passive fire protection systems that are nowadays considered essential to stop the spread of fire and toxic gases and fumes. In the unlikely event of fire, for example, flame and heat should not be able to spread from a fire side to a non-fire side of a fire barrier through any openings, gaps or other weak points present within the fire compartment. Effectively fire stopped, the risk to human life and expensive property is minimised and, equally important, allowing a specified time line for safe evacuation procedures to be realised.
Frequently, however, more developer or building owner attention is focused on other passive fire protection systems, often to the detriment of efficacious fire stopping solutions. This human but short sighted tendency to many potential risks means that the overall passive fire protection system will not achieve its promised fire performance. A typical example is a fire rated partition or ceiling with numerous types of penetrations for mechanical and electrical services such as electrical cabling, cable trays and plastic piping etc. If these are not fire stopped correctly with internationally benchmarked fire stopping systems, fire and toxic fumes will – usually with alarming rapidity – spread to the non-fire side of the fire compartment, sometimes with tragic results.
In fact, the challenges to fire stopping solutions start during product and system development, and how proven test results are interpreted and implemented in the market. Understanding these challenges certainly assist in creating the correct perceptions for passive fire systems generally and specifically for fire stopping applications.
In overall terms, openings through which services penetrate have to be fire stopped in such a manner that the fire resistance of the barrier is not compromised. This means that if a wall or floor has a fire resistance level (FRL) of 120/120/, -/120/120 or even -/120/30, the surrounding area and indeed the entire finished construction must have the same FRL. The only exception is where structural adequacy of penetration seals themselves is not measured. The FRL of the finished seal outlined in the above system would therefore be expressed as -/120/120 or -/120/30.
Around Asia, various fire test standards are observed in the built environment and fire science industries. These are typically British Standards (BS), Australian Standards (AS) and American Standard (ASTM). Some local standards do apply and deviation from most accepted test standards are made to suit the conditions. Further assessments are obtained through recognised test laboratories, when and as necessary.
In fire tests, the temperature on the unexposed side of the specimen is measured at various locations. This temperature is taken not only on the surface of the barrier and fire stopping system but also on the services themselves. If insulation criteria on the services are required, a tested prototype with insulation performance that matches the application is also necessary. The test results must show that the insulation on the services meet the insulation criteria.
Clearly, compliance on fire stopping containing metal penetration is difficult, as temperature will quickly transfer by conduction through the metal elements. Some local building codes may allow waiving of insulation on services where the service is protected such that combustible material cannot be located within 100mm of the penetrating service, for a distance of 2m from the penetration, and it is not located within an escape exit.
In some countries, where fire tests are conducted with services penetrating masonry walls, the results may not be applied to drywall construction. Tests on similar and separate construction models are required.
Similarly, where fire tests are conducted with services penetrating drywall constructions, the results may be used in conjunction with all other wall types, provided that certain conditions such the thickness of the wall, the layers of the boards being used, the fire resistance of the wall are met. It is important to note that these have to be evaluated separately by a recognised, registered testing authority.
If the FRL of the separating element of construction through which service penetrations pass is not known, it is a sensible suggestion to state that the fire stopping system will perform for as long as the separating element retains its integrity and insulation, or for as long as the approved FRL of the fire stopping system.
The building owner is also obliged to ensure that their structure being built clearly takes into full consideration the fire safety needs of its occupants. All consultants have the role of specifying clearly the project specifications for the type of fire stopping to be applied and also on the fire resistance according to the local building regulation requirements. The system manufacturer has the role of ensuring that the system is tested according to the relevant test standards and proposing correct application and installation for the recommended solution.
When fire stopping is installed, the contractor must adhere to the system guidelines and installation procedures outlined by manufacturer. If possible a certified installer is tasked to carry out the installation works. Site building inspection must be carried out by all concerned parties to ensure that the specified fire stopping system is installed correctly and will function up to promised performance in a fire event.
In Asia as elsewhere, everyone – from building owners and developers right through to local authorities, project consultants, contractors and fire stopping system application manufacturers – plays a significant role in integrating and installing life and property saving fire science technologies.
Indeed, it is the professional responsibility, dedication and commitment of all stakeholders to ensure that appropriate fire stopping solutions are applied progressively and as comprehensively as possible.
Too much emphasis is sometimes focused on building regulations that enforce the obligatory use of fire stopping systems. On the other hand, there is an increasing body of evidence to suggest that the proper integration of fire stopping systems into an overall, holistic fire protection plan is a positive and ongoing trend in Asia. This is as good for life safety and the protection of the built environment as it is for business and continued long term economic prosperity in general.
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