Fire ratings are commonly referenced throughout construction projects, but the terminology can often cause confusion. Understanding what a fire rating actually means is essential when specifying access panels, riser doors, and other compartmentation products.
Fire ratings are used to describe how long a product can maintain its performance when exposed to fire under controlled test conditions.
What is a fire rating?
A fire rating is the classification given to a product after successful fire resistance testing. The rating confirms how long the product can withstand fire exposure while maintaining specific performance criteria.
Typical fire ratings include:
- E30
- EI30
- EI60
- EI120
The number refers to the duration, in minutes, that the product achieved during testing. For example:
- 30 = 30 minutes
- 60 = 60 minutes
- 120 = 120 minutes
| Classification | Integrity | Insulation | Duration |
|---|---|---|---|
| E30 | Yes | — | 30 minutes |
| EI30 | Yes | Yes | 30 minutes |
| EI60 | Yes | Yes | 60 minutes |
| EI120 | Yes | Yes | 120 minutes |
What does “E” mean?
Integrity (E) measures the ability of a product to:
- Prevent flames passing through
- Restrict hot gases
- Maintain compartmentation during a fire
A product classified as E30 has maintained integrity for 30 minutes during testing. This means the assembly prevented fire penetration for the tested duration, but it does not necessarily control heat transfer.
What does “EI” mean?
An EI classification includes both:
- Integrity (E), and
- Insulation (I)
In addition to stopping flames and hot gases, insulation limits the temperature rise on the non-fire side of the product. This helps reduce:
- Heat transfer
- Ignition risk to nearby materials
- Radiated heat into adjacent areas
For example, EI60 means 60 minutes of integrity and insulation performance.
| Performance | E — Integrity | EI — Integrity & Insulation |
|---|---|---|
| Stops flames and hot gases | Yes | Yes |
| Limits heat transfer to the protected side | — | Yes |
Why insulation matters
An integrity-only product may stop flames but still allow significant heat transfer through the surface. An insulated product helps maintain safer temperatures on the protected side of the wall or ceiling construction.
This can be particularly important in:
- Escape routes
- Protected corridors
- Residential compartment walls
- High-risk environments
How fire ratings are achieved
Fire ratings are determined through laboratory testing, commonly to BS EN 1634-1:2014 + A1:2018.
During testing:
- The product is installed into a representative wall or ceiling construction
- It is exposed to controlled furnace temperatures
- Performance is monitored over time
The test continues until failure criteria are reached.
Furnace temperatures rise rapidly
Fire tests follow a standard time–temperature curve, where temperatures increase rapidly. Typical furnace temperatures can exceed:
- 500°C within minutes
- 800°C+ during longer-duration tests
This places significant stress on door leaves, frames, seals, locking systems and ironmongery.
Fire ratings and real-world applications
Different buildings and applications require different levels of fire performance. Examples may include:
- Service risers
- Corridors
- Plant rooms
- Ceiling void access
- Protected escape routes
The required fire rating will normally be determined by the building design, compartmentation strategy, Building Regulations and fire engineer requirements.
Fire rated does not mean everything is covered
A fire rating only applies to:
- The tested construction
- The tested configuration
- The tested installation method
Changes to wall type, hardware, frame design, panel size or installation method may affect performance unless covered by further assessment or extended application evidence.
Installation is just as important
Even a successfully fire-tested product can underperform if installed incorrectly. Correct installation is critical to maintaining:
- Seal compression
- Structural support
- Compartmentation integrity
Always follow manufacturer installation guidance, tested construction details, and approved fixing and sealing methods.
Key takeaway
Fire ratings provide a recognised way of understanding how a product performs during fire exposure.
- E = Integrity only
- EI = Integrity and insulation
The number indicates how many minutes the product achieved under test conditions.
Final thoughts
When specifying fire-rated access panels or riser doors, it’s important to look beyond the headline rating alone. Always consider the wall or ceiling construction, the installation method, supporting test evidence, and whether integrity-only or insulation is required.
A correctly tested and installed product plays a vital role in maintaining compartmentation and supporting building safety.
Related reading
- BS EN 1634-1: Fire Resistance Testing Explained — the test standard behind fire ratings
- What Is Fire Compartmentation? — why fire ratings exist
- Smoke Tested Access Panels & Riser Doors — the smoke companion to fire testing
- CE & UKCA Marking on Access Panels — how marking applies
Ready to specify?
Browse the fire-rated access panel and riser door ranges, or contact the Technical Service team for BS EN 1634-1 test evidence and installation detail drawings.
FAQs
What is a fire rating?
A fire rating is the classification given to a product after successful fire resistance testing. The rating confirms how long the product can withstand fire exposure while maintaining specific performance criteria. Typical fire ratings include E30, EI30, EI60 and EI120 — the number refers to the duration, in minutes, that the product achieved during testing.
What does the "E" in a fire rating mean?
E stands for integrity. Integrity measures a product’s ability to prevent flames passing through, restrict hot gases, and maintain compartmentation during a fire. A product classified as E30 maintained integrity for 30 minutes during testing — it prevented fire penetration for the tested duration, but does not necessarily control heat transfer.
What does the "EI" in a fire rating mean?
EI means integrity and insulation. In addition to stopping flames and hot gases, insulation limits the temperature rise on the non-fire side of the product. This helps reduce heat transfer, ignition risk to nearby materials, and radiated heat into adjacent areas. For example, EI60 means 60 minutes of integrity and insulation performance.
Why does insulation matter?
An integrity-only product may stop flames but still allow significant heat transfer through its surface. An insulated product helps maintain safer temperatures on the protected side of the wall or ceiling. This is particularly important in escape routes, protected corridors, residential compartment walls and high-risk environments.
How are fire ratings achieved?
Fire ratings are determined through laboratory testing, commonly to BS EN 1634-1:2014 + A1:2018. The product is installed into a representative wall or ceiling construction, exposed to controlled furnace temperatures following a standard time-temperature curve, and monitored over time until failure criteria are reached. Furnace temperatures can exceed 500°C within minutes and 800°C during longer tests.
Does a fire rating cover every situation?
No. A fire rating only applies to the tested construction, the tested configuration and the tested installation method. Changes to wall type, hardware, frame design, panel size or installation method may affect performance unless covered by further assessment or extended application evidence.
Does installation affect fire performance?
Yes. Even a successfully fire-tested product can underperform if installed incorrectly. Correct installation is critical to maintaining seal compression, structural support and compartmentation integrity. Always follow manufacturer installation guidance, tested construction details, and approved fixing and sealing methods.
