Passive fire protection, UK wide

Fire Compartmentation Surveys

Compartmentation is one of the most important parts of passive fire protection. It keeps fire and smoke contained, protects escape routes and buys people time to get out. A survey from AL23 Safety tells you whether yours is present, effective and fit for how your building is used. Where it falls short, we tell you exactly what to put right. We work with responsible persons and duty holders across the UK.

Book a compartmentation survey

What is fire compartmentation?

Dividing a building so fire stays where it starts

Fire compartmentation divides a building into fire resisting sections or compartments, using fire rated walls, floors and ceilings. Every opening, from a doorway to a cable or pipe penetration, is sealed with tested fire stopping so the compartment holds together when it matters.

It contains the fire

Keeping fire close to where it starts limits damage and protects the rest of the building.

It protects escape routes

It gives people time to leave and supports strategies such as stay put or phased evacuation in residential and healthcare buildings.

When compartmentation is missing, damaged or breached, fire and smoke spread far faster than the design ever intended.

What is a fire compartmentation survey?

The check that examines it properly

A fire risk assessment might flag a concern about compartmentation. A compartmentation survey is what examines it properly, a detailed inspection of your building's fire resisting construction.

We check whether compartment walls, floors and the elements around them were built correctly and whether they are still intact and effective today. That includes finding breaches caused by services, alterations or simple wear over the years.

Non intrusive first, intrusive by agreement

Most surveys start on a non intrusive basis. Where construction cannot be confirmed by eye or a hidden defect is suspected, we carry out intrusive inspection by agreement first.

What we inspect

From compartment walls to the cavities behind them

A compartmentation survey from us typically covers:

Compartment walls and floors
Service penetrations and the fire stopping around them
Roof spaces, floor voids and cavities
Risers, shafts and service cupboards
Cavity barriers, fire dampers and seals where present
Fire doors that form part of the compartmentation
Fire resisting construction protecting escape routes

We assess what we find against Approved Document B, the relevant British Standards and any existing fire strategy for the building.

How it differs from other fire checks

Three checks, often confused

These terms get mixed up. A compartmentation survey sits between a whole building risk assessment and a narrow fire stopping survey.

Whole building

Fire risk assessment

Looks at fire safety across the whole building at a high level, including compartmentation as one of many factors.

The strategy

Fire compartmentation survey

Takes the wider view of whether your compartmentation strategy is present, continuous and effective across the building, with fire stopping assessed as part of that bigger picture.

This survey

Seals and joints

Fire stopping survey

Focuses narrowly on the seals at service penetrations and joints within fire resisting elements.

The legal picture

From the Building Regulations to the golden thread

Compartmentation is required by law at design and must be kept effective in use.

Approved Document B, Building Regulations

Requires buildings to be divided into fire resisting compartments to limit fire spread and protect escape routes. This applies mainly at the design and construction stage.

Regulatory Reform (Fire Safety) Order 2005

The Responsible Person must manage fire risk in the building and maintaining compartmentation is part of the general fire precautions that involves.

Fire Safety Act 2021

Confirmed that fire risk assessments must consider the building's structure, including compartment walls, floors and fire doors.

Building Safety Act 2022

For higher risk buildings, compartmentation information feeds the golden thread of building safety records.

A survey is often the clearest way to show these duties are being met, especially where the original fire strategy is unknown or undocumented.

When to survey

Confirm it, rather than assume it

A compartmentation survey is worth carrying out when:

Even a building that was fully compliant when it was built can be compromised over time by alterations, damage or poor maintenance.

Your fire risk assessment has raised concerns about compartmentation
The building has been refurbished or had services installed that may have breached fire barriers
You manage high rise, multi occupancy or complex buildings that rely on stay put or phased evacuation
The original fire strategy is unclear, incomplete or missing
You want to confirm, rather than assume, that your building still performs as designed

Your report

Clear, prioritised and evidenced

After the survey you get a clear, prioritised report that includes:

Where required, we can also provide annotated floor plans and compartmentation drawings marked with the compartment lines and defect locations.

Findings on the condition and continuity of your compartmentation
Photographic evidence of every defect
Each issue referenced and rated by severity
References to the relevant standards and guidance
A prioritised action plan for remedial work

Why AL23 Safety

Surveyed by people who understand how fire moves

Compartmentation is only as good as the understanding behind the survey. Because we have in-house fire engineering capability, our surveys are carried out by people who understand how fire and smoke actually move through a building, not just how to tick a checklist.

That means we do more than list defects. We explain how your compartmentation is meant to work, how it supports your fire risk assessment and fire strategy and what to prioritise to put things right. We work with building owners, facilities managers, housing providers and duty holders right across the UK.