Facades & Fire Safety: Performance Route – Going Big on Testing
Performance based routes to fire safety compliance allow specifiers and installers to take a step back and really consider how an entire facade system would react in the event of a fire.
The performance criteria for these tests are included within BR 135 and one of two test methodologies should be used: BS 8414-1: 2002 or BS 8414-2: 2005. Complete façade systems that have been successfully tested to these standards can be deemed compliant for the applications they have been tested in.
The large scale testing of the performance based route provides data that is more reliable than that of small scale tests, solving many of the issues of the linear approach. However, with the number and variety of façade systems and materials increasing all the time, it would be virtually impossible to test every single combination. To resolve this, BCA Technical Guidance Note 18 provides an alternative with Desktop Study Reports.
This approach requires a fully qualified fire specialist to draw up a report on the facade system. The specialist uses their knowledge of building materials’ reaction to fire and existing large scale fire test data to assess whether they believe the proposed system will meet the performance criteria of BR 135. It therefore acts as a sensible alternative when precise test data for the proposed façade system does not exist, but there is sufficient existing fire test data relevant to all of the components comprising the assembly, available to be able to make a proper assessment.
The report must be supported by specifically referenced test data for the components within the system (BBA certificates or product datasheets will not suffice). In addition to fire test data, the specialist will also typically require further information including:
- Section details
- Fire barrier / fire stop details
- Material specifications
Evidence supplied in a Desktop Study Report is recognised as an acceptable method of demonstrating compliance for both building control and Buildmark warranty purposes by the National House Building Council (NHBC).
Regardless of which route to compliance is being considered, it is always worth checking with the building control body and warranty provider for the property in the first instance, as the specified construction may already meet the requirements in many applications.
The final route to compliance, Fire Safety Engineering approach, goes into even greater detail than the performance routes, scientifically analysing every element of a building including the geometry, ignition risk and factors restricting fire spread. We’ll take a close look at this in the next blog on 19th January.
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