Why Compartmentation Testing Is Overlooked and Undervalued in Fire Safety – But is its Key

Subscribe for the latest industry news, technologies and resources.

We care about your data in our privacy policy.

Compartmentation is related to fire stopping in walls and floors, to reduce the spread of fire. Compartmentation often relates to room integrity airtightness testing to ensure that a room is sufficiently sealed, to hold in the gaseous extinguishing agent once its been actuated. Liquefied Gaseous systems are typically made up of CO2, FM200® or Novec™ 1230, and non-liquefied systems are typically Inergen® or Nitrogen. Leak sites in the room could mean that the comparted area may not withhold the fire or gaseous extinguishing agent, which has been specifically designed for the space (called design concentration). 

The likelihood of the gaseous system effectively extinguishing the fire gets lower and lower as the protected area becomes larger than the size that the extinguishing system was designed for. The technology exists right now to support Door Fan Testing in providing a holistic and thorough integrity airtightness test of critical infrastructure.

What is the opinion of leading researchers on compartmentation? 

Leading researchers and scientists agree that the size of the compartments and their relation to fire resistance is key. As well as size, issues in the quality of compartmentation walls can come from maintenance, minor works and refurbishments. Contractors carrying out such tasks can occasionally destroy the compartmentation integrity of the wall, floor or ceilings if they were unaware that the area is a comparted space. This is emphasised in a review by the BRE (Building Research Establishment) report from 2015, stating that: “The biggest issue with fire protection in concealed spaces is that of quality of construction. Poor workmanship, with inappropriate materials, resulting in the inadequate protection of concealed spaces, are the main reasons for fire (and smoke) spread via these routes.” 

Therefore, following maintenance it is “good practice” to ensure the fire resistance of walls, floors and ceilings and to safeguard again if necessary. 

Emphasised by the BRE is the important of compartmentation, because if it is not upheld, lives are put at stake, “The fire protection of concealed spaces is of prime importance because any deficiencies in installation and materials are not readily apparent and may quickly be covered over. Any inadequacies in such fire protection cannot be observed by the building users and, unlike other engineering provisions within the building, will not be apparent by its impact on everyday life. Any inadequacies in the fire protection of concealed spaces will only become apparent during the very time that their effectiveness is required – during a fire.” Without means to observe any issues with compartmentation, people entrust their lives to the fire protection in buildings and therefore those who maintain buildings must ensure that the highest standards are kept and exceeded so that they do in fact protect, in the event of a fire.

What are the standards for compartmentation?


The regulations demand that compartmentation is upheld for the safety of the individuals, who entrust their lives into its integrity. Approved document B, Fire Safety, Volume 2, Buildings other than dwelling house states that: 8.0 Every compartment wall should form a complete barrier to fire between the compartments they separate. 8.35 – any stairway or other shaft passing directly from one compartment to another should be enclosed in a protected shaft so as to delay or prevent the spread of fire between compartments. However, despite regulations best effort to promote the implementation of compartmentation and room integrity, the last review of the Building Regulations Approved Document B was made in 2006 (12 years ago) and its next review was not due to be completed until this year, 2022 (which would then be a gap of 17 years), meaning that the attention that is deserved is often disregarded.  

• ADB B3-4 “the building shall be designed… so that the unseen spread of fire and smoke… is inhibited” 

• Appendix B Breaching fire separation “to ensure effective protection again fire, walls and floors providing fire separation must form a complete barrier, with an equivalent level of fire resistance provided to any openings such as doors, ventilation ducts, pipe passages or refuge chutes.” 


The industry is sometimes minimally compliant or even non-compliant due to a lack of understanding of fire systems and their connection to compartmentation. 

• The storage container contents shall be checked at least every six months. a) Liquefied gases: for halocarbon agents, if a container shows a loss of agent in quantity of more than 5 % or a loss of pressure (adjusted for temperature) of more than 10 %, it shall be refilled or replaced. 

• At least every 12 months it shall be determined whether boundary penetration or other changes to the protected enclosure have occurred that could affect leakage and extinguishant performance. If this cannot be visually determined, it shall be positively established by repeating the airtightness testing for enclosure integrity in accordance with Annex E. 

• Where the integrity airtightness test reveals increased leakage that would result in an inability to retain the extinguishant for the required period, remedial action shall be carried out. 

• A.3.2 Engineered systems: need information and calculations on the amount of extinguishant; 

As stated above, leak sites in the room could mean that the comparted area may not withhold the fire or gaseous extinguishing agent, which has been specifically designed for the space (called design concentration). Gaseous extinguishing/suppression systems however are installed to protect special hazards in critical infrastructure as their key objective. If the room has leak sites in its compartmentation and the gaseous extinguishing agent cannot be contained in the room, then the critical infrastructure/building will not be protected from fire. 

To understand how fire resistant a compartment is, an inspection of the overall condition of the existing fire compartments is needed, as well as an assessment of the condition and effectiveness of the sealing of wall/soffit interfaces and an inspection of existing fire seals applied to service penetrations through fire compartment lines. 

The technology exists right now to solve this problem. 

Technology must solve industry problems. Not only to become a successful business in terms of profitability but in terms of sustainability and genuinely offering service to the industry in order to reduce risk, improve safety and hopefully have a small part in saving lives. Coltraco Ultrasonics have provided a smart solution to quick and easy assurance of compartmentation using ultrasound to detect signal leaking through any apertures within the barriers. 

The Portascanner® AIRTIGHT 520 is beneficial to fire safety markets as it is the only instrument capable of both locating and quantify air leaks, thereby ensuring enclosures are sealed effectively as specified in fire safety standards such as NFPA 2001. Specifically, NFPA 2001 states that “all total flooding systems shall have the enclosure examined and tested to locate and then effectively seal any significant air leaks that could result in a failure of the enclosure to hold the specified agent concentration level for the specified holding period and “the protected enclosure shall be inspected annually or monitored by a documented administrative program for changes in barrier integrity or enclosure dimensions”. The Portascanner® AIRTIGHT 520 ensures that this standard can be met conveniently and at low cost.

Users of the Portascanner® AIRTIGHT 520 are able to locate air leaks and quantify their significance, thereby ensuring that any further airtightness tests such as the Door Fan Test or the PULSE test pass first time, reducing costs. It can be also used in instances where pressurisation tests are impossible or impractical to perform. Once tested, users will possess an electronic record of leak data to facilitate a more systemised approach to enclosure integrity airtightness testing.

The Portascanner® AIRTIGHT 520 provides interpretation of the fire resistance of the desired locations by identifying and quantifying the overall leakage of the room. The advantages of being able to accurately detect the exact leak locations and their size are self-evident when considered alongside the resistance to collapse and transfer of excessive heat. In a case where there is too much leakage in a room, the Portascanner® AIRTIGHT 520 is an unrivalled ideal for the rapid and accurate identification of these sites so that they can be sealed. It is lightweight, fast and easy to use, allowing leak site detection to increase its operational efficiency and speed to a degree that has never been seen thus far in the Fire Industry.

Get in touch

You can reach us anytime via phone or email, we aim to respond to all enquiries within 24 hours (excluding weekends and bank holidays)


Come say hello at our Technical Laboratory.

Coltraco Ultrasonics
NETPark Research Institute
Joseph Swan Road
TS21 3FB

United Kingdom


Monday - Friday (excluding bank holidays) from 8:30am to 6:00pm, UK.

Tel (Sales & HQ): +44 20 7629 8475
Tel (Technical): +44 1740 618 240