Preventing Firefighter and Evacuee Deaths in Timber Buildings

On 6 April 2010, a devastating fire at Shirley Towers in Southampton claimed the lives of two firefighters. Investigations found that falling ceiling-mounted services, which had become detached under fire conditions, caused fatal entanglement. Earlier, a similar tragedy at Harrow Court had identified comparable factors contributing to firefighter deaths.

The lessons learned from these incidents led to significant changes in UK fire safety regulations, particularly concerning the performance of ceiling fixings and suspended building services during fire.

Today, the construction industry is undergoing another major transformation.

A Changing Built Environment

As the UK moves toward Net Zero construction, mass timber is increasingly replacing concrete and steel as a primary structural material. Beyond its sustainability benefits, mass timber enables exposed architectural finishes that celebrate the natural material — especially at ceiling level.

To preserve this aesthetic, mechanical and electrical (M&E) services such as pipework, cabling, ventilation, and fire systems are often suspended directly from ceilings, creating the modern industrial appearance widely seen in contemporary buildings.

However, this shift introduces new and largely unexamined fire safety challenges.

Recent research by D. Kinnersley has investigated how common steel fixings used in mass timber perform under fire conditions. Testing revealed significant reductions in fixing strength between pre-fire, during-fire, and post-fire states. Forensic analysis of char formation around threaded fixings has helped explain the mechanisms of weakening — demonstrating that larger or stronger fixings do not necessarily provide safer outcomes.

While sprinkler systems may benefit from inherent self-protection, other suspended services — including wiring and HVAC systems — may fail during fire. Such failures could compromise fire compartmentation and create dangerous obstructions or entanglement hazards for both evacuating occupants and responding firefighters.

Addressing a Critical Knowledge Gap

This project aims to deliver the research needed to establish reliable methods and future standards for ensuring fixing performance during the most critical phases of a fire:

• Occupant evacuation
• Firefighter search and rescue operations
• Maintenance of safe escape and access routes

Existing standards governing the attachment of suspended services (such as BS 8539) were developed primarily for concrete structures. Equivalent guidance for timber construction does not yet exist.

The challenge may be described as “the same, but different.”
In past incidents, fixings themselves failed under fire exposure. In mass timber buildings, the opposite risk may arise: fixings remain strong while the timber substrate weakens, allowing systems to detach unexpectedly.

Building Safety Into Net Zero Construction

As construction methods evolve rapidly to meet sustainability goals, fire safety knowledge must evolve alongside them. This research seeks to anticipate and prevent foreseeable risks before they lead to future tragedies.

By developing evidence-based guidance for fixing performance in mass timber buildings, the project aims to protect firefighters, safeguard occupants, and ensure that the transition to Net Zero construction is matched by equally robust advances in life safety.

The project is due to be completed at the end of May 2026.