Episode 7
What is meant by the term 'fire rating'?

What is the fire performance data or ‘fire rating’ of products within a cable management system?

Since the tragedy of Grenfell, many contractors/buyers within the M&E sector request fire performance data as part of a product’s technical specification. With the industry heading towards a compliant, evidence-based, traceable future this is a question which will continually asked, and it deserves an answer. As a provider to the sector, it is a question we are asked weekly.

“Can you provide the fire performance data of channel, threaded rod etc”

To remove confusion around fire performance data and to tackle this topic in an open and honest manner, we decided to put it as a core topic in one of our podcasts.

After listening to the full podcast, the following questions can be answered:

• What does the term ‘fire rating’ mean?

• Why the German standard DIN 4102-12 is not a suitable standard for testing cable basket.

• Why BS 476 fire curve is not a reliable indicator for the performance of cable management systems

• Why should the industry understand the meaning of a ‘fire rated’ product?

• How can an M&E contractor follow best practice?

“There is no point having a fire-rated product that after 120 minutes has the load-bearing capacity of a leaf” (Tim Brown, 2020)

Define ‘fire rating’

When a buyer requests the ‘fire rating’ of a particular product, there is no definitive answer. What they are commonly looking for is the classification shown on the BS 476 fire curve. To carry out a test compliant with the British Standard, a specific material is put under a furnace for a set amount of time (usually, 2 hours) whilst the temperature gradually rises. Time and ambient temperature are recorded until a product is deemed to ‘fail’. After the test has been carried out, the manufacturer can say that their product can withstand temperatures of ‘X’ over a given time.

Why is the standard DIN 4102-12 not a suitable standard to provide the fire performance data of a cable management system?

To put it simply DIN 4102-12 is a standard to test cable. It therefore can’t be validated against a whole cable management system, for example a cable basket.

Why BS 476 shouldn’t be relied upon.

BS 476 is the go-to British Standard for identifying a ‘fire-rating’. However, just because a product can withstand a certain ambient temperature it does not mean that the product has the same working load. To answer this question as best as possible, there needs to be a universal test which covers not just individual components that make up an M&E support, but the whole system, including all associated anchors/fixings. The results should also take into consideration how the ambient temperature effects the working load capacity a complete M&E support.

When specifying cable management systems, the buyer should ask:

1. Has the fire test been carried out by a third party?

2. Is the test based on an ambient temperature or based on the performance of the product at the end of the test?

3. How is the load performance of a cable management system after the fire test.

Why it is important to understand terminology?

In an industry often dominated by generational product language, terms used can be confusing and misunderstood. For example, if we simply take anchors/fixings, a ‘deformation-controlled anchor’ are frequently referred to as: wedge anchors, drop-ins, red-heads, ceiling anchors etc. This misconception can damage trust within the supply chain.

For example, M&E contractors may assume that if a cable has undergone fire testing then that would mean that the whole cable management system has achieved a fire rating. Unfortunately, this isn’t the case. As there is no harmonised fire rating standard for a cable management system, the manufacturer can’t provide a ‘fire performance rating’ in the truest sense of the word. Removing the confusion around technical terms helps to set expectations between the supply chain.

As the industry moves towards a traceable, evidence-based future, terminology must be clear. If a manufacturer has claimed that a product is ‘fire rated’ to a certain standard, and that product fails, then the manufacturer is liable.

How about other fixings?

The topic of fire rating is also referred to when a buyer specifies anchors/fixings. As we know, anchors/fixings are often left to the last minute and therefore specified anchors may not be fit for purpose.

However, if an ETA-approved anchor has been specified then fire performance data can be given as it is shown through the ETA certificate. However, regardless of the ‘fire-rating’ recorded, it does not take into consideration the impact temperature has on the load-bearing performance of the anchor.

Are there any other organisations looking into this issue?

There are several key organisations within the industry that looking to create a universal standard. If we look at BEMA, they have spent time and resources creating a separate cable management committee.

As Tim notes within the podcast, the committee is completely devoted to creating a standard. However, standards take a long time to create, as it requires the full ‘buy-in’ from all relevant stakeholders. Not only must the standard be created but it then must be promoted within the industry to help educate the supply chain. This is off course a separate but just as important task.

How can an M&E contractor abide by best practice?

In an industry faced with tight deadlines, time is of critical importance. As with many issues within the industry, early and continued engagement with the relevant stakeholders is necessary to ensure the whole supply chain is confident to answer the questions around, the ‘fire rating’ of a product. Without this necessary early, open and honest continued engagement then it is highly likely that products will be supplied on-site without the necessary performance data. As a provider to the M&E sector we recommend that contractors ask the following questions, when given a ‘fire rating’ of a product.

• What is the fire rating of the product?

• The first route a contractor should take is to speak to the manufacturer’s technical department and ask the following questions:

• What tests have been carried out?

• Have those tests been carried out by a third party?

• Can you provide test results?

• Can you provide performance data after testing?

To conclude, the industry is heading in the right direction with the supply chain in agreement that any asset that is supplied on-site must have quantifiable evidence to back-up its performance. As the building safety bill is amended, it will include the ‘Golden Thread’ legislation. To put it simply the intention of this legislation is to ensure that one stakeholder, otherwise known as the ‘duty holder’ will be responsible for managing the performance data on each and every product supplied to site that could potentially impact the health and safety of the building or its occupants.

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