Effective smoke control is a critical part of a fire-resisting doorset’s performance, yet the gap beneath a door has historically presented a significant weakness. IFSA has established that leaving the threshold unsealed is wholly unsatisfactory for smoke control, with even relatively small gaps capable of causing leakage rates to exceed permitted levels.
Fact Sheet 4: Smoke Sealing of Doorway Thresholds sets out what the industry needs to know and why established approaches to testing and specifying doorsets need to change.
During a fire, restricting the movement of smoke can be every bit as critical as containing flames. A door that appears correctly specified and installed may still fail to provide the intended level of smoke protection if leakage is allowed beneath it.
Historically, the treatment of the threshold during smoke testing has not adequately reflected this risk. Leaving the threshold unsealed does not provide satisfactory smoke control, while simply taping the gap during a test creates conditions that are unlikely to be replicated once the door is installed and in everyday use.
The result is a potentially serious discrepancy between a doorset's performance during testing and its ability to restrict smoke in the real world.
For manufacturers and specifiers, relying on an artificial test condition is no longer enough.
IFSA's position is that an appropriate threshold seal should be incorporated and tested as part of the complete door assembly. This provides a representative assessment of how the doorset will actually perform, helping to achieve the required smoke control while allowing the door to operate freely during normal use.
The implications of getting this wrong extend beyond technical performance. Those responsible for manufacturing, specifying and selecting fire-resisting doorsets need to be confident that the complete assembly provides the level of protection required of it.
A seemingly minor gap beneath a door should not become the weak point that compromises the performance of the entire doorset.
Our Fact Sheet 4: Smoke Sealing of Doorway Thresholds explains the issue in detail, including the rationale behind its position and how appropriate threshold sealing should be approached.
For manufacturers, specifiers and fire safety professionals, it provides important guidance for ensuring that doorsets are designed and tested with real-world smoke control in mind.
Download Fact Sheet 4 using the thumbnail to the right to understand the requirements and ensure your approach to doorway threshold sealing is fit for purpose.
Fact Sheet 4: Smoke Sealing of Doorway Thresholds
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