How Fire Compartmentation Is Breached Without You Realising

Fire compartmentation is one of the most effective ways to limit the spread of fire and smoke in a building. It’s a cornerstone of passive fire protection, designed to give occupants time to escape and emergency services time to respond. But it’s also vulnerable, especially when those working on your property don’t realise it’s there, or don’t understand its importance.

From electricians to decorators, even minor works can damage compartmentation in ways that go unnoticed until it’s too late. In this article, we explain what fire compartmentation is, how it’s often breached without anyone realising, and how you can check for and prevent these hidden risks.

What Is Fire Compartmentation?

Fire compartmentation is the division of a building into fire-resistant zones (or compartments). The aim is to contain a fire within the area of origin for a defined period—usually 30, 60, or 120 minutes—by using fire-resistant walls, floors, ceilings, doors, and barriers.

These compartments help to:

• Prevent the rapid spread of fire and smoke

• Protect escape routes

• Safeguard high-risk areas (like plant rooms or storage spaces)

• Support phased evacuation and fire-fighting efforts

In residential flats, care homes, offices, and public buildings, compartmentation is essential for meeting UK fire safety laws, including the Regulatory Reform (Fire Safety) Order 2005.

How Compartmentation Gets Breached Without You Realising

Despite its importance, compartmentation is frequently and often unintentionally damaged by everyday work. The breaches may be small, but their impact can be critical.

Here are some of the most common ways compartmentation is compromised:

1. Cables and Data Installations

IT contractors running new network or alarm cables often drill through walls, ceilings, or risers. If these are compartment walls and the holes aren’t sealed correctly with fire-rated materials, fire and smoke can pass through them easily.

2. Plumbing and Pipework

Adding or rerouting heating, water, or waste pipes usually involves creating openings through compartment walls or floors. If fire collars, wraps or sealants aren’t used properly, these penetrations become weak points.

3. Ventilation and Ductwork

Ducts passing through compartments must be fitted with fire dampers that close in the event of a fire. Without them, or if dampers are incorrectly installed, fire and smoke can travel through the ducting and spread quickly between zones.

4. General Maintenance and Decorating

Something as simple as drilling into a wall to hang shelves or install fixtures can breach a fire-rated barrier, especially if the installer doesn’t know they’re working on a compartment wall or ceiling.

5. Fire Doors and Door Frames

Removing self-closers, trimming fire doors, fitting non-compliant locks, or failing to maintain door seals all reduce the effectiveness of the door—and by extension, the compartment it protects.

Why These Breaches Are So Dangerous

Even a small, unsealed gap can allow smoke and fire to bypass your defences. This puts lives at risk and can cause your fire strategy to fail, even if everything else is working correctly.

Compromised compartmentation can lead to:

• Rapid smoke spread into escape routes

• Reduced evacuation time

• Loss of property and equipment

• Breaches of fire safety law

• Potential criminal or civil liability

Most worryingly, these faults often remain hidden, especially in suspended ceilings, riser cupboards, plant rooms or behind wall finishes.

How to Inspect for Compartmentation Issues

You don’t need to be a fire engineer to spot the warning signs. If you manage a building, carry out regular visual checks in the following areas:

Above Ceilings and in Riser Cupboards

• Look for cables or pipes that pass through walls or floors without proper sealing

• Check for gaps around ducts or service trays

• Ensure that any foam, batt or mastic used is fire-rated and not crumbling or missing

In Corridors and Common Areas

• Ensure fire doors are in good condition, self-close properly, and have working intumescent strips and smoke seals

• Make sure the ceiling tiles are in place where fire-rated ceilings are used

In Loft Spaces or Behind Boxing

• Check for unsealed penetrations between flats or between commercial and residential areas in mixed-use buildings

Fire Strategy Drawings (if available)

• Compare what’s shown in your fire strategy or compartmentation drawings to the current condition of the building

If you’re unsure, a qualified fire-stopping contractor or fire risk assessor can carry out a more detailed inspection.

What to Do If You Find a Breach

1. Document It
   Record the location and take photos.

2. Assess the Risk
   Consider whether the gap or fault could allow smoke or fire to move between compartments or into escape routes.

3. Take Interim Measures
   Where a serious breach is found, restrict access or use alternative escape routes until it’s fixed.

4. Arrange Repairs by Competent Persons
   Fire stopping must be done using the correct materials and methods by someone trained in passive fire protection.

5. Review Your Fire Risk Assessment
   If compartmentation has been compromised, your risk profile may have changed—update your documentation accordingly.

 

 

How to Prevent Future Damage

To maintain your fire compartmentation:

• Label compartment walls and risers clearly to inform contractors

• Brief all tradespeople on the fire strategy before they begin work

• Require fire-stopping sign-off for any penetration or installation work

• Carry out routine inspections as part of your maintenance programme

• Keep a record of all alterations to compartment boundaries

 

 

Final Thoughts

Fire compartmentation can quietly save lives, but only if it’s intact. Unfortunately, it’s all too easy for even well-meaning contractors to compromise your fire strategy without realising.

If you manage a building, especially one with multiple tenancies or shared areas, make regular checks and keep a close eye on any works involving walls, ceilings or services. Fire safety depends just as much on what you can’t see as what you can.

For expert advice on fire protection and prevention measures, contact Martyn Young Fireproofing Consultancy on 07585 896648