ASFP TG3 Update: Strengthening Guidance on Firestopping and Cavity Barriers

The ASFP’s Technical Group 3 (TG3) met virtually on 3 July 2025, bringing together 25 experts from across the fire protection industry. Convened by Andrew Taylor (ASFP), the group’s focus remains on two critical elements of passive fire protection: firestopping and cavity barriers. These measures are central to preventing the internal spread of fire and smoke within buildings, helping to safeguard both lives and property.

This update provides an overview of TG3’s current priorities, progress on guidance documents, and the key actions shaping future industry standards.

Progress on Technical Guidance Documents

A significant portion of the meeting was dedicated to reviewing and updating ASFP’s suite of Technical Guidance Documents (TGDs) and Advisory Notes (ANs).

• TGD 19 (Curtain Walling Systems)
  A revised draft was presented to address gaps not covered in BS EN 1364-6, helping the UK industry transition smoothly to the new European standard. The group agreed to amended wording in the foreword to clarify its role as a transitional document. The ultimate goal is to withdraw TGD 19 by September 2029, once the sector has adapted fully.
• TGD 17 (Service Penetrations)
  Work is underway to update this document. A draft will be circulated to members in July, with comments due in August.
• Advisory Notes (AN 0.5, AN 1, AN 2, AN 8)
  Following industry feedback, revised drafts are being prepared. AN 8 (covering service support centres) will require a complete re-write due to ongoing challenges on site. Engagement with BESA is planned to align approaches on supports and fixings.

These publications play a vital role in ensuring consistent, practical guidance is available across the supply chain, from designers to installers.

Cavity Barrier Challenges

Cavity barriers featured prominently in discussions. Concerns from fire and rescue services about smoke spread in open-state cavity barriers (OSCBs) are being addressed through new guidance. An Advisory Note is in development to highlight the risks of cold smoke leakage and outline best practice.

Additionally, a request was raised for clearer guidance on slab edge details, where external wall systems interface with floor slabs. Current Building Regulations (AD-B, Diagram 8.1) offer limited clarity. TG3 agreed that new advisory material, supported by diagrams, should be developed to help practitioners understand when and how firestopping and cavity barriers should be applied at these junctions.

The Data Sheet Project

The group also considered the government’s request for an industry-led portal to share fire test data. TG3, along with ASFP Council, agreed that while certification and classification documents should be made publicly available, full fire test reports are not appropriate for general release due to their technical complexity. Work is now underway to scope the creation of a centralised, publicly accessible portal for certificates, which would support transparency while maintaining professional standards.

Wider Technical Issues

TG3 is also tackling several related areas that impact firestopping performance:

• Golden Thread Checklists – A new template is being drafted, drawing lessons from ducts and dampers guidance, to help ensure service penetrations are properly recorded and managed.
• Flexible Walls and Shaft Walls – Further work is required to clarify performance expectations where firestopping interacts with these wall types.
• Steel Sections Through Compartment Lines – The group acknowledged challenges in testing beams that pass through compartment boundaries, given current furnace limitations. Work has begun to illustrate possible configurations and seek practical solutions.

Looking Ahead: Regulation and Competence

With the regulatory landscape evolving rapidly, TG3 discussed recent updates, including:

• Government adoption of recommendations from the Grenfell Tower Phase 2 Inquiry.
• Ongoing reform of the Construction Products Regulation (CPR), with new UK terminology shifting from “Safety Critical” to “Products Critical to Safe Construction.”
• Implications for European Technical Assessments (ETAs), with ETAG 026-based approvals expiring from January 2026.

The group also noted progress on the Competence Framework (SLG12), an essential initiative for raising standards across the sector, albeit one requiring careful development due to its complexity.

Key Takeaways

TG3 continues to play a crucial role in shaping the technical and regulatory framework for firestopping and cavity barriers. Current priorities include:

• Updating TGD 17 and TGD 19 to reflect modern practice and standards.
• Producing advisory notes on cavity barrier performance, cold smoke risks, and slab edge detailing.
• Developing industry tools such as the golden thread checklist and a fire test data portal.
• Engaging with broader issues such as competence, inspection regimes, and regulatory change.

By addressing these challenges, TG3 is ensuring that guidance keeps pace with both innovation and lessons learned from past failures. For ASFP members and the wider industry, the group’s work represents a vital step towards safer buildings and more reliable fire protection systems.

Next TG3 Meeting: 12 November 2025 (Hybrid).