Historic Timber Doors: The IFE Guide to Fire Resistance

In historic building restoration projects, the role of doors in fire safety assessments is one of the numerous pertinent concerns. On the one hand, doors are essential components in defining the building, its visual identity, and its functionality. On the other hand, in fire safety, a door can be crucial if it forms part of the compartmentation works and typically requires specifications to ensure the safe evacuation of occupants.

For these reasons, the dilemma often arises regarding the management of doors that possess historical, if not also artistic, value but do not, if not only partially, meet the requirements of various regulations regarding the closing elements of activities subject to fire risk.

In instances where assessments do not permit an immediate decision, the Institution of Fire Engineers (IFE) Guide to the Fire Resistance of Historic Timber Panel Doors, published in July 2021, may prove beneficial. This comprehensive guide addresses the matter in detail. According to the Guide, edited by the Special Interest Group for Heritage Buildings, preserving heritage doors in their original settings is the most secure approach. Transporting them to storage and replacing them with contemporary replicas does not guarantee their safety in the future, particularly when the intended purpose for storage is forgotten.

As previously mentioned, fire-resistant and smoke-resistant doorsets play a pivotal role in ensuring safety. Smoke, being more hazardous than fire itself, can cause injury and death through asphyxiation, loss of visibility, and the presence of flammable gases.

Furthermore, smoke poses a threat to artefacts and building fabric away from the fire’s origin. Doors may necessitate modifications to facilitate the safe evacuation of occupants and protect property from fire and smoke by maximising the time available for safe escape and containment of fire and smoke within the room of origin or fire compartments.

Keep escape route clear

In historic buildings, the presence of old materials and structures can make the building more vulnerable to fires and other hazards. It is therefore crucial that escape routes are kept free from obstacles, in order to provide a safe and rapid escape route, especially in a context where rescue operations may be more complex due to the historic characteristics of the building. So, keeping escape routes clear of smoke is vital. These routes and staircase enclosures should be free of combustibles and ignition sources to prevent the spread of fire and smoke from adjacent rooms. In any case, doors opening onto dead-end escape routes and protected staircases should have a degree of fire and smoke resistance.

The importance of compartmentation

For the aforementioned reasons, historic buildings, which are frequently rich in cultural assets, artworks, decorations, and materials of historical and architectural significance, are susceptible to irreparable damage from fires. Consequently, the implementation of fire compartments serves as a protective measure, effectively limiting the spread of fire and confining damage to specific sections of the building. This approach enhances the likelihood of recovering or safeguarding the most valuable works, as compartmentation proves instrumental in mitigating the rapid spread of fire. By subdividing the building into fire-resistant compartments, fire and smoke are contained, thereby minimising damage to the structure and its contents, particularly collections. Furthermore, this strategy facilitates the fire service by reducing the size of the fire they must confront and preventing the spread of fire between different groups within multi-occupied buildings.

The process for determining the upgrading of the doors

In this context, the document seeks to elucidate the decision-making process for determining the necessity of modifications, the extent of upgrades to a door, and potential actions to accommodate diverse viewpoints, including those of enforcement authorities. While the upgrading section specifically addresses single swing panel doors, the remainder of the document is applicable to other types of doors.

As the IFE is a British institution, the methodologies employed to assess fire resistance performance are governed by the British Standard 476: Part 22 and BS EN 1634-1 and 2. These standards establish the test conditions and criteria for evaluating the fire resistance of timber door sets. The outcomes are subsequently presented in terms of integrity, primarily focused on preventing the passage of hot gases and flames, and insulation, which aims to prevent an excessive temperature increase on the non-risk side.

The document is structured into four chapters (Introduction, Factors Affecting the Performance of Fire Doors, Upgrading of Fire Doors, and Design and Use of the Matrix) and is accompanied by four appendices: Recommendations from the Trenton Fire Engineering Report 2011, Assessment of Fire Loads and Severity in Heritage Buildings – September 2011 by Simon Vickers, Testing of the Effect of Room Size on Fire Growth, and Comparison of Matrix Examples.

In 2022, SINTEF (Stiftelsen forindustriall og teknisk forskning, “The Foundation for Technical and Industrial Research”) collaborated with RISE Fire Research and NIKU (Norsk institutt for kulturminneforskning) to publish the guideline titled “Fire Resistance Upgrade of Cultural Heritage Doors.”