Fire safety issues in modern buildings rarely arise from a single point of failure. More often, they emerge from a series of defects that, taken together, undermine a building’s fire strategy: missing cavity barriers, service penetrations not suitably firestopped, or a fire compartment line wall that fails to provide compartmentation at ceiling level.
Individually, each presents its own level of risk, and collectively they may lead to serious failings in the building’s fire safety. Each issue can create pathways for the passage of unseen smoke and fire, allowing them to spread far faster and further before detection.
Across residential and other buildings, fire engineers, fire safety professionals, and building surveyors continue to see the same patterns of failure.
The most common fire safety defects encountered?
Combustible façade materials
External wall systems remain one of the highest-risk areas. Insulation, the external face of the facade, spandrel panels, or decorative elements are often found to incorporate combustible materials.
Missing or poorly installed cavity barriers
Cavity barriers are designed to prevent fire and smoke from travelling unseen through façades and voids. They can often be missing, poorly fitted, or compromised by gaps, rendering them ineffective at stopping the passage of fire and smoke.
When cavity barriers fail, it allows the potential for a fire to breach other areas of the building from where it originated. It can move laterally and vertically behind cladding, into new compartment lines of the building.
Inadequate fire stopping at service penetrations and interfaces
Modern buildings contain multiple penetrations for pipes, cables, ducts, and structural connections. If these openings through walls and ceilings within compartment lines remain unsealed, they become direct routes for the passage of smoke and flame.
Common defects include oversized penetrations, incomplete or damaged seals, or incorrect fire-stopping materials and methods, particularly within service risers and at floor slab levels.
Compartmentation that exists only on drawings
While design drawings may show clear compartment lines, what is built, or later altered, often tells a different story.
We commonly discover breaks in fire-resisting walls above suspended ceilings, behind dry lining, within risers, or at party walls. Such defects may be present from the original construction or may follow the completion of refurbishment or fit-out work without a proper and up-to-date fire strategy review.
Complex layouts and linked buildings
Podiums, connected blocks, and mixed‑use developments can behave like a single fire compartment in practice, even when the design never intended them to.
That makes the fire strategy far more complicated. As buildings evolve, original fire strategies and assumptions around evacuation, fire separation, and fire-fighting access should be reassessed against how the building functions today.
Escape routes that no longer comply.
Changes in building use are common. Walls move, offices become flats, retail units become residential and over time, these alterations can narrow, obstruct, or extend escape routes well beyond permitted travel distances, often without anyone realising the fire strategy has been compromised.
Why do these fire safety issues matter now?
The regulatory landscape has shifted significantly.
The Fire Safety Act 2021 clarified that risk assessments in multi-occupied residential buildings must cover not just internal standard parts, but also:
- The structure,
- External walls (including cladding, balconies, and windows),
- Flat entrance doors.
The Fire Safety (England) Regulations 2022 introduced ongoing compliance duties, including routine fire door checks, resident engagement and information, wayfinding signage, secure information boxes, and FRS (Fire and Rescue Service) plans, with enhanced measures for buildings over 18 m in height.
The Building Safety Act 2022 further strengthened record-keeping obligations, information sharing between duty holders, and enforcement powers.
As a result, issues are now far more likely to present compliance, liability, and enforcement risks.
Independent forensic fire safety analysis
At Rimkus, our experts safeguard people and property against fire risks, ensuring compliance and protecting the long-term value of your building assets within the UK.
We support clients with
- Fire strategy and design reviews
- Intrusive inspections and surveys
- Identification of fire safety defects
- Responsibility attribution
- PAS 9980 Fire Risk Appraisals of External Walls (FRAEW)
- Remediation design and independent peer review
Our focus is on practical, proportionate, evidence-led solutions that reduce risk and support compliance in complex buildings.
Frequently Asked Questions
What are the most common fire safety defects in residential buildings?
Frequently encountered defects include combustible façade materials, missing cavity barriers, inadequate fire-stopping around services, breaches in compartmentation, and non-compliant escape routes resulting from building alterations.
Why are fire safety defects dangerous?
Individually, each defect presents its own level of risk, but when combined, they may lead to serious failings in a building’s fire safety, creating pathways for fire and smoke to spread beyond the design assumptions of the building’s fire strategy.
Who is responsible for fire safety compliance in multi-occupied buildings?
Under current legislation, responsibility may sit with multiple duty holders, including building owners, managing agents, and accountable persons, depending on the building type and risk profile.