Pennington Choices Blog

Passive Fire Protection: Fire door regulations and fire strategy plans

Written by Pennington Choices | Jun 26, 2025 11:30:49 AM

What is passive fire protection?

Passive fire protection is the cornerstone of an effective fire safety strategy for your buildings. Unlike active fire protection, such as fire suppression systems, alarms, and extinguishers, a passive fire protection system is built into the fabric of the building itself. Its aim is to slow or prevent the spread of fire, giving occupants time to evacuate and the fire and rescue service time to respond.  

Passive fire protection relies on fire-rated materials and systems that remain in place before, during, and after a fire. These include fire doors, fire resisting construction, and other components designed to maintain the building’s structural integrity under fire conditions.  

Buildings with stronger passive fire protection measures tend to limit fire spread more successfully. For example, in 2020–21, only 7% of fires in high-rise flats (10+ storeys) spread beyond the room of origin, compared to 10% in low-rise flats and 12% in houses or bungalows, largely due to stricter and more consistent use of passive fire protection. 

Source: Fire Safety: Property Protection Final Report

This blog will outline the key components of an effective passive fire protection strategy, with in-depth insights into fire compartmentation, fire doors, and the importance of a robust fire strategy plan. 

To catch up on expert insights, relevant legislation, and frequently asked questions around passive fire protection, catch up on our recent fire safety webinar, Passive Fire Protection: Legislation, compartmentation, and fire doors, for everything you need to know.  

 

Key components of passive fire protection

To ensure robust passive fire protection, the following components should be considered in your fire safety strategy:

  • Fire compartmentation
  • Fire doors
  • Fire curtains 
  • Fire and smoke dampers
  • Firewalls 
  • Intumescent strips and coatings 

Each of these elements plays a vital role in resisting fire spread and maintaining the structural performance of the building in the event of a fire. Let’s dive deeper into some of the most essential components.

 

Fire compartmentation 

Fire compartmentation ensures that: 

  • The building is designed so its stability will be maintained in a fire for a reasonable time period
  • Fire spread between adjacent buildings is prevented
  • The interior is sub-divided using fire-resisting construction and/or has suitable automatic fire suppression systems
  • Fire and smoke are restricted from spreading through hidden voids and cavities 

To ensure the effectiveness of the compartmentation within your building, a Compartmentation Survey is the most reliable way to identify any gaps and provide peace of mind.  

Interested in finding out more? Download our FREE Guide to Effective Fire Compartmentation to assess your approach and ensure compliance.  

 

The fire resistance of a compartment is measured using an REI rating, for example, REI 30 or REI 60. Each letter represents an aspect of the compartmentation’s performance:

  • R: Load-bearing capacity
  • E: Integrity (ability to prevent the passage of flames and hot gases)
  • I: Insulation (ability to reduce heat transfer from one side to the other) 

For example, an REI 30 wall will provide 30 minutes of structural stability, flame resistance, and heat insulation. 

Fire strategy

Before carrying out a Compartmentation Survey, it’s important to have a Fire Strategy in place to understand where your building requires passive fire protection to be in place. This document, prepared by a competent fire safety professional, outlines all fire safety measures relevant to your building, including:

  • Means of warning, such as smoke detectors
  • Means of escape for anyone inside the building 
  • Passive fire protection measures  
  • Protection against external fire spread 
  • Fire and rescue services access and facilities 
  • Fire safety management measures  

Need support developing your Fire Strategy? Our qualified and accredited team can help you identify where compartmentation is required and ensure your approach is fully compliant. 

 

Fire doors and fire door regulations

Fire doors are fundamental to maintaining the integrity of fire compartments. Since a door creates an opening in a fire-resistant wall, the fire door itself must restore the fire resistance of that wall. 

What is the purpose of a fire door? 

Fire doors are designed to:

  • Contain smoke and flames
  • Protect evacuation routes
  • Starve fires of oxygen and limit their development
  • Enable safe access for firefighting teams 

What makes a fire door compliant? 

A compliant fire door must meet stringent testing and certification requirements:

  • Fire-tested to BS 476-22 or BS EN 1634-1
  • Certified, for example, with a BWF-Certifire label or BM TRADA Q-Mark plug
  • Globally assessed variants may use equivalent fire resistance data across the manufacturer’s range, but all components must be tested together and installed correctly 

Certification must be backed by the manufacturer’s instructions, installation guidance, and test evidence. 

Fire door ratings

Fire doors are typically either 30-minute (FD30) or 60-minute (FD60) fire rated:

  • FD30 doors have a 44mm thick leaf
  • FD60 doors have a 54mm thick leaf
  • FD30 and FD60 doors are generally hung on three hinges, however, heavier FD60 doors may require four hinges. Some manufacturers also offer alternatives like piano hinges, which run the full length of the door and frame. The hinge type and number depend on the manufacturer’s specifications.
  • Fire doors may be single or double leaf and can be either solid or glazed. Regardless of type, they must always close correctly into the frame, without warping or gaps, and must not be wedged or held open unless held open using a compliant electronic device. 

Closers and signage 

Not all fire doors include automatic closing devices. Some may be fitted with signage such as:

  • "Fire door keep locked": meaning the user is responsible for closing and locking the door
  • "Automatic fire door keep clear": indicating that the door is connected to the alarm system and will close automatically when triggered 

Signage is important for communicating the intended use and function of each fire door to building users. 

Seals and fire stopping

All compliant fire doors will have either smoke seals, intumescent strips, or both.

  • FD30 doors typically have a continuous strip around the frame, which is interrupted at points of ironmongery (locks and hinges). These breaks must have adequate fire stopping using intumescent wraps or similar materials.
  • FD60 doors will also have a second, unbroken strip around the perimeter of the frame, in addition to the one interrupted by ironmongery. 

Correct frame-to-leaf gaps are essential for performance. The default industry position is a 3mm gap, but tolerances range from 2mm to 4mm, and some manufacturers permit as little as 1.5mm, depending on their guidance. 

Common compliance issues

Examples of non-compliant fire door practices include:

  • Fire extinguishers or wedges used to prop doors open
  • Unapproved ventilation grilles cut into doors (for example to cool a server room)
  • Maglocks or security devices drilled through the fire door leaf, which may breach its tested fire integrity 

If you’re looking for further support in navigating your passive fire protection duties and ensuring your buildings are safe from the spread of fire, get in touch with our team of experts.