As many know, the safety of humans in the event of a building fire relies on the performance of a building’s fire resistant doorsets.
Fire resistant doorsets need to be tested, and preferably third-party certified, to confirm the correct design and detailing. Using our FAQs and simple guides below, let us help you understand some of the key issues involved.
For testing, certification and other related queries, call BM TRADA on +44 (0)1494 569750.
What are the components of a fire-resisting timber doorset?
The term 'doorset' refers to the complete element:
• Door leaf or leaves
• Door frame
• Essential functional hardware
• Intumescent seals and smoke sealing devices
There is no such thing as a stand-alone, fire-rated door component. For example, the frame can only be considered as ‘fire rated’ when it is machined in accordance with the tested details and installed, with the appropriate door, as a complete doorset. Therefore, if the frame and door leaf are made by different manufacturers, or the frame is made on site, its specification must match exactly that of the complete fire tested doorset.
How is fire resistance of a doorset determined?
There is no PAS or Standard for manufacturing fire-rated doorsets.
A doorset must be tested to determine its resistance to fire expressed in terms of time. A doorset is exposed to a ‘standard’ fully developed fire in a test furnace until failure occurs according to a certain criteria. Performance testing is to evaluate integrity and insulation in accordance with either BS 476 or BS EN 1634.
Typically, a fire-rated doorset should:
• Be in accordance with a specification or design that has been shown by test to be capable of meeting that performance; or
• Be assessed from test evidence against appropriate standards, as meeting that performance.
What factors should I consider when specifying intumescent strips?
The intumescent seal will activate when heated to fill the gap between the leaf edge and the frame.
Specification must be as tested or assessed for that particular doorset. This is the case for:
• the size of the intumescent seal
• the location of the seal, and
• the type of seal.
Interchanging between different seal types and/or manufacturers is not permitted, unless there is test evidence available to demonstrate otherwise. The type of seal is particular to the manufacturer, and characteristics, performance and function can vary considerably.
What information on test/assessment reports is available from the test laboratory?
Manufacturers must have their design tested by a laboratory accredited by the United Kingdom Accreditation Service (UKAS).
Assessments are written in terms of performance judged against BS 476-22.
All door manufacturers’ test and assessment data is held in confidence by the relevant test laboratory. It cannot be made available without the written permission of the test sponsor.
Reports are usually valid for five years. They relate only to what has been tested and allow no variations.
How can I upgrade existing doorsets to enhance their inherent fire resistance?
There are numerous methods for upgrading available with no 'one-size-fits-all approach. The only way to ensure that the most appropriate method is chosen – and to have the enhanced integrity performance underwritten – is by commissioning a site survey by a qualified fire engineer.
The relatively large number of components that make up a fire-rated doorset are integral to its performance. The following should be considered:
4. Customer requirements
See TRADA’s WIS 1-32 Upgrading timber doorsets for fire resistance for advice on this topic.
What must I consider when installing glass into my fire door?
A wide variety of fire-resistant glazing systems are available, but not all fire-rated doorsets can tolerate glazing.
As this is a potential weak spot, it is essential to check:
• test evidence/assessment data to confirm that the doorset can accept glazing
• test evidence to show that the glazing system and glaze type have been tested in timber-based doorsets
• that the glazing is installed by a competent person who ensures the exact glazing guidelines are followed so that the performance is not compromised.
There is currently no legal or statutory requirement to be certified to glaze fire-resisting doors. However, training to demonstrate competency is recommended.
Can I fit a letter plate or eye viewer to my fire-rated door?
Fitting a letter plate or eye viewer will breach a fire-rated doorset and has the potential to allow a direct passage for hot gases and flames. It is therefore important that:
• There is test/assessment data for the fire-rated doorset to tolerate the ironmongery.
• The ironmongery being fitted has been previously tested in a doorset of comparable construction.
• The maximum height at which the letter plate can be fitted is adhered to (under the appropriate Standard).
General advice for non-essential door furniture is use components that are face fixed, otherwise they must be tested or assessed by a UKAS-accredited laboratory.