Breaking Down The Language of Regulation: What is Integrity, Stability, and Insulation?

Breaking Down The Language of Regulation: What is Integrity, Stability, and Insulation?

30th January 2024

bsi logo

Designing for fire safety in construction can be a complex subject. Recent revisions to building regulations have further tightened rules, bringing additional responsibilities on manufacturers and contractors to ensure correct specification.

In this article, George Danzey-Smith, Director of Commercial & Technical at ARC, unpicks the language of regulation, helping contractors and other stakeholders understand the products available in the context of these new frameworks.

What Is Fire Resistance?

Specifying the correct fire protection products has never been more important. With new regulations bringing heightened scrutiny across the industry, it’s crucial we all understand the solutions available and their features and benefits.

Fire resistance is not a property of an individual material but the measure of the performance of a complete system or construction when exposed to high temperatures. When evaluating and selecting passive fire protection systems, three essential performance criteria are defined and tested for against the regulations (BS 476-20-24): Stability, integrity and insulation. A careful consideration of each is required to achieve a robust fire protection specification.


Stability, denoted with the letter R in product literature, refers to an element or system’s ability to remain stable and resist collapse in a fire event. The extreme heat conditions present during a fire can expose certain materials to structural damage, and the resulting collapse has a significant impact on the safety of a building and its occupants. A product is rated by the number of minutes it can remain stable, so a product with R60 must withstand collapse for 60 minutes.

In practice, stability is often absent from technical data and product information. For an element to achieve an integrity rating, stability is assumed as a mandatory base factor. If a system loses its stability and collapses, it automatically loses its integrity performance ability. Therefore, the stability rating is often not explicitly denoted, as it is assumed to be at least equal to the integrity rating, which is more readily available in product data.


One of the most pivotal features of any fire-stopping product is its ability to compartmentalise a fire. In terms of fire safety, buildings can be understood in compartments. In a fire event, buildings comprising of one or more rooms, spaces or storeys [compartments] must be constructed in a way that prevents the spread of fire from one area to another. This is also the case where adjoining or neighbouring buildings are in close proximity.

In this context, integrity, denoted by the letter E, refers to an element or system’s ability to prevent flames and hot gases such as smoke from physically passing through the product. In other words, how long a product can compartmentalise or prevent a fire from spreading between rooms, storeys or buildings.

Non-combustible materials are favourable as they generally perform better, preventing spread for longer than other materials. When displayed in product data, integrity is displayed using the E followed by the number of minutes of fire integrity it is capable of withstanding. For example, our new TCB square product achieves E60, which is tested and validated to stop the spread of fire for up to 60 minutes.

The ARC TCB Square


Another pivotal aspect of preventing the spread of fire is insulation. No, this is not the typical wool, foam or board products you might find stuffed in your loft. In terms of fire safety, insulation, denoted in product literature by the letter (I), refers to an element or system’s ability to limit surface temperature rise on the non-fire side of the element. In other words, how long it takes for heat to travel through the product when one side is exposed to a fully developed fire.

Testing is completed using thermocouples, which take temperature readings at various points across the surface of a product. On average, the non-fire side of the element should not exceed 140C but may reach a maximum of 180C as a hot spot. The number of minutes a product can prevent this temperature rise will quantify its rating.

Understanding Risk

While the importance of educating and training contractors to help demystify regulations should not be underestimated, what also can’t be lost here is the need for correct installation. The fire resistance properties of products and systems are only effective if they are installed accurately and properly by trained teams who understand the products they are dealing with. Therefore, as an industry, it is our responsibility to ensure the information required for correct installation is up-to-date and easily accessible.

The key message, which cannot be emphasised enough, is that the ‘best’ solution is the one that minimises risk and the potential for performance gaps to occur when people start to use the building. In this context, understanding regulation is only one aspect of specification.

Only with robust training and increased focus across the entire industry to ensure knowledge is shared, and installation instruction is as accessible as possible, can greater, more consistent building safety standards be achieved.

Discover more about ARC and our role in the fire safety industry >