Falconer Chester Hall’s Senior Architect, Tom McTernan, joined the Architects’ Journal Fire Safety Panel to discuss the evolving standards of passive fire protection in design.

Tom drew on his recent project experience to highlight lessons learnt when working with structural steel and existing buildings, especially in retrofit projects. His talk focused on three key areas:

Approaching projects with steel frames, and how they interface with existing timber floors.
The challenges of retrofitting a four-storey furniture factory with a three-storey zinc extension.
Why sequencing and co-ordination are essential to avoid costly on-site changes.

Steel protection and specification

Tom explained common issues around steel protection. For example, steel can be exposed to the elements during construction, or junctions with SFS may lack adequate testing. Composite deck systems also raise questions about cavity infills, while intumescent paint can present limits and cost challenges.

To manage these risks, Tom stressed the need for early collaboration. Boarding manufacturers, fire engineers, and structural engineers should agree specifications for each element, from board types and section factors to fire ratings.

Integration with firestops and timber floors

Tom also spoke about integration with firestops. Cavity barriers and boarded steel must align to deliver the required fire performance. When working with existing timber floors, understanding tested systems is vital. He noted the different limiting temperatures (300°C for joists and 500°C for steel) and emphasised the value of sequencing to avoid unnecessary disruption.

The design process and Gateway compliance

According to Tom, a fully resolved structural model is critical. Bolts, stiffeners, and bracing all affect the ability to board steel effectively, and changes late in the process can cause major challenges.

He also linked these lessons to the Gateways process under the Building Safety Act. Collating test data for each scenario helps build strong completeness and compliance statements, particularly when projects involve untested or bespoke details.

Industry consensus

The panel agreed on several points:

Use fully tested and typical details wherever possible.
Where deviations are required, make sure risks are clearly understood.
Involve consultants early to resolve complex scenarios.

This collaborative approach, echoed by fellow panelists, is essential to raising fire safety standards and ensuring compliance across the industry.

👉 Find out more about the panel on the Architects’ Journal website.