The Hidden Fire Risk of Uncoordinated Trades

A completed piece of passive fire protection can be remarkably short-lived on a busy construction site.

A penetration is sealed and photographed on Monday. On Wednesday, another cable is pushed through it. A cavity barrier is installed correctly, then moved to accommodate a bracket. A compartment wall is completed, then drilled for containment. A fire door is commissioned, then adjusted because the floor finish has changed.

Nobody necessarily intends to compromise the fire strategy. Often, each trade is simply completing its own package.

That is precisely the problem.

Passive fire protection depends on continuity, and continuity is vulnerable when trades work without understanding how their work affects the systems around them. Installation and sign-off are therefore only part of the process. Completed fire protection must remain protected, alterations must be controlled and safety-critical details must be reinspected when other work affects them.

Passive Fire Protection Does Not Belong to One Trade

Fire stopping may be installed by a specialist contractor, but its success depends on far more than the fire stopping team.

Dryliners form the walls. M&E contractors route services through them. Electricians add cables. Mechanical contractors install pipework and ducts. Ceiling contractors conceal the work. Joiners install doors. Flooring contractors alter threshold conditions. Façade installers work around cavity barriers and brackets.

Each trade touches part of the fire strategy.

This makes passive fire protection unusual. Responsibility for installation may sit with a specialist, but responsibility for preserving it extends across the site.

A perfectly installed penetration seal can be rendered ineffective by somebody who arrives later with a drill.

The question for the principal contractor is therefore not simply whether passive fire protection has been installed correctly. It is whether the construction process protects that work afterwards.

Fire Stopping Is Particularly Vulnerable

Service penetrations are constantly changing during construction.

Cable requirements develop. Additional data lines appear. Pipe routes move. Controls are added. Commissioning reveals the need for another connection. An opening thought to be complete suddenly needs one more service.

The easiest route is often through an existing penetration.

From a practical point of view, the temptation is understandable. The opening already exists. The fire stopping material is visible. Pushing another cable through may seem less disruptive than forming and recording a new penetration.

From a fire protection point of view, it can completely change the detail.

The original fire stopping system was selected for a particular opening, service arrangement and loading. Adding another cable or pipe can damage the seal, change the spacing between services or move the installation outside the tested evidence.

Simply applying more sealant afterwards does not necessarily restore compliance.

The revised arrangement needs to be checked against the approved system, properly reinstated and recorded again.

A Signed-Off Penetration Can Become Non-Compliant

Sign-off records a condition at a particular moment.

It does not protect that condition from everything that happens afterwards.

This distinction matters on projects where passive fire protection is inspected progressively. A penetration may be photographed, tagged and approved weeks before the surrounding M&E package is complete. If another trade subsequently alters it, the original record no longer describes what is present.

The paperwork may still show green.

The wall may no longer deserve it.

Final verification therefore matters. Areas that have remained active after passive fire protection installation should be checked again before ceilings, risers and wall linings are closed.

Where work has changed, the evidence must change with it.

Compartment Walls Are Easy to Damage

A fire-resisting wall can appear robust, but its performance depends on the complete construction.

Later trades may drill through boards for cables, containment, pipework, fixings or controls. Small openings may be left untreated because they do not look significant. Larger penetrations may be cut without reference to the original wall system.

Even fixings deserve consideration.

The presence of a fire-rated wall does not mean anything can be attached to it anywhere. Uncontrolled penetrations, damaged board edges and poorly formed openings can affect the tested assembly.

Principal contractors need a clear process for work that crosses compartment lines. Trades should know where those lines are before they begin drilling.

This sounds basic. On a large project, with changing teams and hundreds of metres of construction, it is anything but automatic.

Compartmentation needs to be visible in the coordination process, even when the finished construction is designed to disappear.

Cavity Barriers Can Be Moved, Cut or Compressed

Cavity barriers are particularly vulnerable because much of their work happens out of sight.

They may sit within façades, ceiling voids, roof spaces and concealed cavities. Once installed, later trades may need to pass brackets, services or other components through the same space.

A barrier can then be cut back, compressed, displaced or left with a gap around the new obstruction.

The change may appear minor. The consequences are not.

Cavity barriers depend on continuity and correct installation against the surrounding construction. A barrier that no longer reaches its intended boundary, or has been cut around another component without a suitable detail, may not provide the expected restriction to smoke and flame spread.

Coordination is particularly important at interfaces: façade brackets, service routes, structural connections and openings. These are the places where separate packages meet and where responsibility can become blurred.

The cavity does not recognise contractual boundaries.

Fire Doors Change After Installation

Fire doors are also vulnerable to follow-on work because they remain visible and usable throughout later stages of a project.

A correctly installed door can be altered by several seemingly harmless changes.

New floor finishes can reduce or increase the threshold gap. Decoration can contaminate seals. Hardware can be changed. Closers may be adjusted because the door feels heavy. Hold-open arrangements may be introduced. Access control equipment may require drilling or new ironmongery. Frames can be damaged by nearby works.

The door may have passed inspection before any of this happened.

Fire door sign-off should therefore reflect the finished condition of the surrounding construction and hardware, not an earlier stage when the doorset was technically complete but the building around it was still changing.

The same principle applies after occupation. Fire doors continue to be adjusted, repaired and modified throughout the life of a building.

Compliance is a condition to be maintained, not a certificate to be remembered.

Ceiling Voids Gather the Evidence of Poor Coordination

Ceiling voids often reveal how well a project has coordinated its trades.

They gather cable trays, pipework, ducts, hangers, alarms, lighting and controls into a restricted space. They also contain compartment heads, fire barriers, penetration seals and other passive fire protection that will soon become inaccessible.

When coordination is weak, the void records it.

Extra cables pass through existing seals. Barriers are cut around containment. New holes appear close to previously completed penetrations. Fire stopping becomes difficult to reach because another service has been installed directly in front of it.

Then the ceiling programme arrives.

Closing the ceiling should not be used to end the discussion. It should trigger a final check that the fire protection above it still matches the evidence already recorded.

If the void has changed since inspection, the inspection needs to change too.

M&E Changes Need Fire Protection Change Control

Mechanical and electrical installations rarely remain identical to the first coordinated drawing.

That is normal construction.

The problem arises when an M&E change is treated purely as an M&E matter.

Moving a pipe may create a new penetration. Increasing the size of a service may change the approved seal. Additional cable loading may alter a tested arrangement. Rerouting a duct may introduce another crossing through compartmentation.

Every change that affects fire-resisting construction needs a corresponding fire protection review.

This does not need to become cumbersome. It needs to become routine.

Before a new penetration is formed or an existing seal altered, the trade should know what compartment line it is crossing, what system is already present and how the revised arrangement will be protected.

The alternative is remedial fire stopping after coordination has already failed.

Why Photographic Evidence Has Limits

Photographic records are invaluable, but they can create false confidence if treated as evidence of the current condition rather than the condition when the photograph was taken.

A clear photograph may prove that an installation was correct on a particular date. It cannot prove that nobody altered it later.

This is why photographic evidence should sit within a wider QA process.

Locations need unique references. Alterations need to be recorded. Defects need to be tracked. Areas subject to further work need final reinspection before concealment or handover.

The Golden Thread should describe the building that exists, not an earlier version of it.

A photograph of good work is useful. A photograph of good work that no longer exists is historical evidence.

Protect Completed Work

Passive fire protection needs physical protection as well as administrative control.

Once a penetration, barrier, board system or coating has been completed, other trades should understand that it is finished safety-critical work.

That may require labelling, tagging, temporary protection or clearly defined no-fix zones. On complex projects, compartment walls and protected areas can be marked on coordination drawings so that operatives know when a proposed opening needs approval.

Toolbox talks and site briefings also have value when they are specific. Telling trades to “be careful around fire stopping” is vague. Showing them what must not be cut, drilled or moved is far more useful.

The aim is not to make passive fire protection untouchable. Buildings need services and later changes.

The aim is to make alteration deliberate rather than casual.

Responsibility Sits with Coordination

When one trade damages another trade’s work, it is tempting to treat the issue as a subcontractor problem.

Passive fire protection requires a wider view.

The principal contractor controls the sequence, interfaces and information flow between packages. That puts coordination at the centre of maintaining compartmentation during construction.

There should be clarity over who can authorise alterations to completed fire protection, who is responsible for reinstatement, who reinspects the work and who updates the record.

Without that structure, responsibility tends to appear only after the defect is found.

The best time to decide who owns a damaged penetration is before anyone damages it.

Final Inspection Must Reflect the Finished Building

Progressive inspection is useful because much of passive fire protection becomes concealed before the project is complete. But there also needs to be confidence that critical areas have not been altered since their original inspection.

Final QA should concentrate particularly on areas with heavy follow-on activity: plant rooms, risers, ceiling voids, corridors, service cupboards and major M&E routes.

The inspection should look for new penetrations, damaged seals, moved barriers, altered door hardware and any other change that affects compartmentation.

This final review is not a repeat of every earlier inspection. It is a check that the evidence trail still describes the finished building.

That is a different task, and an important one.

Practical Checks for Principal Contractors

Before areas are concealed or handed over, principal contractors should confirm that:

• Completed fire stopping has not been altered by later service installations.

• New penetrations have been identified, protected and recorded.

• Compartment walls have not been drilled or damaged without suitable reinstatement.

• Cavity barriers remain continuous around brackets, services and other interfaces.

• Fire doors remain correctly adjusted after flooring, decoration and access-control works.

• Later M&E changes have been reviewed for their effect on passive fire protection.

• Completed protection has been clearly identified to follow-on trades.

• Any damaged work has been repaired using an appropriate tested system.

• Revised details have been reinspected after alteration.

• Photographic and QA records describe the final installed condition.

• Areas with significant follow-on activity receive a final check before concealment.

These checks are not an additional layer of ceremony. They recognise that a construction site continues to change after individual packages have been signed off.

Why JW Simpkin Treats Coordination as Part of Fire Protection

At JW Simpkin, the quality of passive fire protection is not judged only at the moment of installation.

The detail needs to survive the rest of the construction process.

That means tested systems, competent installation and accurate records, but it also means communication with the trades working around them. Fire stopping, barriers, boarding, coatings and fire doors exist within a larger construction sequence. Their integrity depends on that sequence being controlled.

A specialist contractor can install the correct system. The wider site team must then allow it to remain the correct system.

This is where good coordination becomes part of the fire protection itself.

Conclusion: Sign-Off Is Not the End of the Detail

Many passive fire protection defects begin after the original work has been completed.

Another cable is added. Another hole is drilled. A barrier is moved. A closer is adjusted. A seal is disturbed.

Individually, these can look like ordinary construction decisions. Together, they can steadily dismantle the compartmentation that earlier trades worked to create.

The answer is not to prevent buildings from changing. It is to control those changes.

Completed fire protection should be identified, protected, reinspected when altered and recorded in its final condition. Principal contractors need to connect the trades that form the compartment, penetrate it, seal it and work around it afterwards.

Passive fire protection is only finished when the surrounding work is finished too.