Does a tested detail for a higher fire rating also cover a lower rating? Tested Detail Queries
In short, a tested detail for a higher fire rating also covers a lower one.
Firstly, it is crucial to understand the difference between integrity and insulation fire ratings. While both aim to maintain a building’s compartmentation, integrity (E) focusses on the duration a wall or floor can resist fire, whereas insulation (I) indicates how long a component can resist the heat transfer from the fire side to the non-fire side of a service penetration seal.
The EI fire rating is located in the table at the bottom left of our standard installation detail drawings. EI ratings are ‘up to’ measurements, meaning that any rating ‘up to’ the one stated in the detail will be covered. For example, a tested detail with an EI 120 rating will also cover a lower rating of EI 60.
Detail QB-FW100-D-20:
At Quelfire, we fire test applications for the duration it takes for the scenario to fail. This ensures the required time is met and the best possible coverage is provided for our customers.
In certain instances, the EI rating may vary. Typically, insulation tends to fail before integrity. Standards for insulation ratings are notably less stringent than those for integrity. During a fire, the temperature on the non-heated side should not exceed 180 degrees centigrade above ambient temperature at any one point as per the BS EN 1366-3 test standard. But if you consider a metal pipe, known for its efficient heat conduction, its heat can compromise the building’s compartmentation quicker than fire itself if the services are sealed compliantly.
Detail QB-CF150-P-10:
Consequently, you may get an E 60 and EI 30 rating, as shown above. Where the required fire rating is EI 60, though you would be covered for integrity, the insulation rating would not be suitable. In such cases, you will require a more appropriate tested detail. Therefore, we encourage you to reach out to our technical team at technical@quelfire.co.uk so we can advise you further.
