In many buildings across the UK, people assume that internal walls, especially stud partitions, automatically offer some degree of fire resistance. But in reality, this is a dangerous assumption. Not all walls are designed to resist fire, and unless they’ve been constructed and tested to a recognised standard, they may fail quickly during a blaze.
Whether you’re a building manager, contractor, landlord or responsible person under the Fire Safety Order, it’s essential to understand how to identify fire-resisting walls and what to do when a wall doesn’t meet the mark.
What Makes a Wall Fire-Resisting?
A fire-resisting wall is one that can withstand fire and heat for a specified period of time, typically 30, 60 or 120 minutes, to help:
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Contain a fire to the area where it started
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Protect escape routes for occupants
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Prevent structural collapse
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Support fire-fighting operations
To be considered fire-resisting, a wall must be built to a recognised standard (such as BS EN 1364-1 or BS 476) and include tested combinations of materials, construction methods and finishing.
It’s not just about the plasterboard or blockwork, it’s about the whole system, including studs, fixings, joints, insulation, sealants and coverings.
Not All Plasterboard Walls Are Fire-Rated
Many internal walls in homes, offices and commercial buildings are made with timber or metal stud frames and plasterboard linings. These walls may look the same as a fire-rated wall, but unless they’ve been built with fire-resistant board and installed to a tested specification, they won’t provide the same level of protection.
For example:
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Standard plasterboard may offer minimal resistance—perhaps 10–15 minutes.
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Fire-rated plasterboard (often pink or marked) can achieve 30–60 minutes, but only if correctly installed.
Mistakes that compromise fire resistance include:
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Gaps in board joints or around service penetrations
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Using the wrong type or thickness of plasterboard
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Missing noggins or incorrect stud spacing
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No intumescent sealant or mastic around wall penetrations
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Poor fixing of boards or inadequate taping/skimming
How to Identify Fire-Resisting Internal Walls
If you’re unsure whether an internal wall is fire-resisting, here’s how to check:
1. Review Construction Drawings or Specifications
Look for clear references to fire resistance, such as:
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“Partition to achieve 60 minutes fire resistance”
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Product codes for fire-rated plasterboard
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Use of specific fire-rated systems (e.g., Knauf, British Gypsum)
2. Check Labels or Markings on Boards (if exposed)
Fire-rated boards are often stamped or coloured, such as:
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Pink face (commonly used for fire-rated boards)
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Codes like “Type F” or performance ratings printed on the board
3. Look for Certification
Ask the contractor or developer for documentation showing that:
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The wall type has been tested to BS 476 or BS EN 1364-1
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It was installed in line with the manufacturer’s specification
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Installation photos or quality control records were taken
4. Inspect Penetrations and Seals
Even a correctly built fire-rated wall can be compromised by:
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Cable trays or pipes passing through without proper fire stopping
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Gaps around sockets or light switches
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Missing intumescent mastic or collars
How to Upgrade a Non-Compliant Wall
If you discover a wall that should be fire-rated but isn’t, you don’t necessarily need to rip it out. There are upgrade options, including:
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Overboarding with fire-rated plasterboard
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Adding fire-resisting mineral wool insulation inside cavities
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Applying intumescent coatings or sprays (in specific cases)
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Properly sealing all service penetrations with tested systems
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Installing fire batt systems or collars around pipes and cables
Always consult a competent fire safety contractor or engineer to assess the best route to compliance.
Where Do Fire-Resisting Walls Matter Most?
While not all internal walls need to be fire-resisting, there are critical locations where they’re essential:
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Between flats or maisonettes
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Along protected escape routes (e.g. corridors, stairwells)
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Separating high-risk areas (kitchens, plant rooms, storage)
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Compartment walls in large commercial buildings
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Fire enclosures for lift shafts, risers, and services
Building Regulations (Approved Document B) and the Regulatory Reform (Fire Safety) Order 2005 both require that fire compartmentation is suitable and remains effective over time.
Don’t Guess, Verify
Assuming a wall offers fire resistance without confirmation is a serious risk. In the event of a fire, a non-compliant wall may fail within minutes, exposing escape routes and placing lives in danger.
Whether you’re responsible for a block of flats, a care home, an office or a school, it’s vital to verify the fire performance of walls that are meant to contain or delay fire. If in doubt, get it assessed.
For expert advice on fire protection and prevention measures, contact Martyn Young Fireproofing Consultancy on 07585 896648