Mechanical and electrical services have a habit of occupying every space left available to them.
Cable trays gather above ceilings. Pipework turns through risers. Ducts cross compartment walls. Brackets, conduits and insulation tighten the remaining gaps. By the time the M&E installation is advanced, passive fire protection is often expected to fit around whatever space is left.
That is the wrong order.
Passive fire protection should be planned before M&E installation begins, while service routes can still be adjusted, openings can still be formed correctly and access remains available. Once pipes, cables and ducts are crowded against walls and soffits, the options narrow. The work becomes harder to install, harder to inspect and more likely to require awkward remedial details.
The fire strategy should shape the service installation, not chase after it.
Start with the Compartmentation Strategy
The first task is to understand where the fire-resisting lines sit.
Compartment walls, fire-resisting floors, risers, protected corridors, shafts and ceiling zones should be identified before service routes are fixed. These lines are not simply marks on a drawing. They are the boundaries the M&E installation must respect.
Every pipe, cable, tray, duct or conduit that crosses a compartment line creates a penetration that must be protected. The more crossings a project creates, the more fire stopping is required and the more opportunities there are for poor coordination.
Good planning asks whether each crossing is necessary.
Services can often be grouped, rerouted or aligned through planned openings. This reduces the number of penetrations, simplifies the fire stopping and improves inspection. A coordinated services zone is easier to protect than a wall scattered with unrelated openings formed at different stages.
The aim is not to prevent services from crossing compartment lines. It is to make those crossings deliberate.
Involve the Passive Fire Protection Contractor Early
Passive fire protection specialists are often brought into a project after the M&E routes have been installed. At that point, they are expected to find compliant solutions for conditions they had no part in creating.
This can lead to restricted access, oversized openings, mixed service penetrations and details that fall outside standard tested systems.
Early involvement changes that.
A passive fire protection contractor can review proposed service routes, substrates, opening sizes, service types and resistance periods before installation begins. Potential conflicts can be identified while changes are still practical. Suitable tested systems can be selected before the opening is formed rather than after it has been filled with services.
This is especially important in risers, plant rooms, ceiling voids and other areas where service density will be high. These spaces can become inaccessible quickly. A short coordination exercise before installation can prevent extensive remedial work later.
Specialist knowledge is most useful before the problem is fixed into the building.
Coordinate Service Routes with Fire-Resisting Construction
M&E coordination is usually driven by capacity, access, maintenance and programme. Fire compartmentation must be part of the same conversation.
Service routes should be reviewed against fire strategy drawings and compartmentation plans. The project team should know where services will cross fire-resisting elements, what type of construction they will pass through and how those openings will be sealed.
The detail will vary according to the service.
Plastic pipes may require collars or wraps. Metal pipes may need suitable penetration seals and consideration of insulation. Cable trays and trunking require tested systems that match the cable loading and opening arrangement. Ducts may require dampers, fire-resisting ductwork or another approved penetration detail.
These decisions should not be left until the installer reaches the wall.
A marked-up coordination drawing can identify planned penetration zones, service types and required fire resistance periods. That gives M&E contractors a clear route and gives the passive fire protection team a known condition to detail.
Form Openings Deliberately
Poorly formed openings create unnecessary difficulty.
Openings that are too large require more complex sealing. Openings that are too tight may not allow the tested installation to be completed correctly. Irregular edges, damaged substrates and multiple unplanned penetrations can all move the detail away from the approved system.
Before M&E installation begins, openings should be sized and located to suit both the services and the proposed fire stopping system.
This requires coordination between designers, builders, M&E contractors and passive fire protection specialists. The opening must provide enough space for the service, its insulation, any required movement and the fire stopping detail. It must also remain within the dimensional limits of the tested system.
The hole should not be treated as an incidental consequence of the service route. It is part of a fire-resisting assembly.
Avoid Overcrowded Penetrations
One large opening may appear more efficient than several smaller ones. Sometimes it is. Sometimes it creates a services cluster that is difficult to protect.
Mixed service penetrations need careful planning. Pipes, cables, trays and conduits behave differently in fire conditions. The selected system must be tested or assessed for the complete arrangement, including service spacing, opening size, substrate and resistance period.
If too many services are crowded into one opening, there may be insufficient room to install backing materials, wraps, collars, batts or sealants properly. Inspection also becomes more difficult because critical parts of the detail may be hidden behind adjacent services.
Grouping services should simplify the fire stopping, not turn it into a puzzle.
Where mixed penetrations are proposed, the tested evidence should be reviewed before installation. If the arrangement is not covered, the design should change while change is still possible.
Leave Enough Working Space
A compliant fire stopping detail needs physical room.
Installers must be able to reach the opening, prepare the substrate, fit the required components and achieve the specified seal depth. Collars need space for correct positioning and fixings. Boards and batts need accessible edges. Sealants need room for proper application. The completed work must remain visible enough to inspect.
M&E routes fixed tight against walls, floors or soffits can make this difficult or impossible.
The project team should establish minimum access zones around planned penetrations. Brackets, valves, flanges and other components should not obstruct the opening or prevent installation from either side where required.
Access must also be considered after the first services are installed. A penetration may be easy to reach when the pipework is incomplete, then become buried once cable trays and ducts are added.
Planning should reflect the finished service arrangement, not just the first installation stage.
Build Fire Protection into the Sequence
The construction programme should identify when passive fire protection will be installed, inspected and protected from later works.
This is not always a single operation.
Some systems can only be completed after all services are in place. Others may need temporary sealing during the works, followed by final completion. Large openings may require staged installation. Penetrations may need to remain accessible until service testing and commissioning are complete.
The sequence should avoid two common failures.
The first is installing fire stopping too early, then allowing later trades to damage it or add services through it. The second is leaving it too late, after access has been blocked by equipment, ceilings or finishes.
A useful sequence is to coordinate the penetration, install the main services, complete the fire stopping once the service arrangement is stable, inspect and photograph the work, then protect it from further disturbance.
Where late additions are unavoidable, they should follow a controlled permit or approval process. New services should not simply be pushed through an existing seal.
Define Responsibility Clearly
Passive fire protection often sits between trade packages.
The builder forms the opening. The M&E contractor installs the services. The fire stopping contractor seals the penetration. Another trade may add insulation. The principal contractor coordinates the programme. The designer defines the required performance.
If responsibility is vague, defects appear in the gaps between those roles.
Before work begins, the project should define who is responsible for identifying penetrations, approving service routes, forming openings, checking substrates, selecting tested systems, sealing temporary openings, completing final fire stopping, inspecting the work and recording the evidence.
The answer should not be “the fire stopping contractor will sort it”.
A specialist installer can only work with the condition provided. If the opening is unsuitable, the service arrangement falls outside the tested detail or access has been blocked, the issue belongs to the wider project team.
Clear responsibility prevents passive fire protection from becoming the last unresolved package on site.
Control Changes During Installation
M&E layouts change. Equipment selections move. Routes are adjusted to avoid structure. Extra cables are added. Pipework changes diameter. These changes are normal, but they must be controlled where they affect compartmentation.
A change to a service route may create a new penetration or alter an approved detail. A larger pipe may require a different collar or wrap. Added cable loading may move a penetration outside its tested scope. Revised ductwork may change the damper or fire-resisting duct requirement.
The fire protection detail must be reviewed when the service arrangement changes.
This is where marked-up drawings and change records matter. The final installation should reflect the final building, not the first coordination model. Any substitutions or revised arrangements should be checked against manufacturer evidence before the work is closed.
A small M&E change can create a significant fire protection consequence.
Plan for Temporary Fire Protection
During M&E installation, compartment walls and floors may remain open for days or weeks. In occupied or phased buildings, this can create an immediate risk.
Temporary fire stopping may be required while services are incomplete. The approach should be agreed before openings are formed. Temporary materials must be suitable for the period and condition of use, and the process for removing and replacing them should be controlled.
This is particularly important in live refurbishment projects, hospitals, schools, residential buildings and phased handovers where parts of the building remain in use.
The permanent detail may be planned for later, but the building still needs protection during the works.
Temporary conditions should never be treated as exempt from fire safety.
Inspect Before Concealment
Passive fire protection should be inspected while it is still visible.
Ceiling voids, risers, service cupboards and boxed-in zones often close soon after M&E installation. Once the work is hidden, verification becomes difficult and remedial work becomes disruptive.
The programme should include inspection hold points before ceilings, walls, risers or enclosures are closed. The inspection should confirm that the installed system matches the service arrangement, substrate, opening size and required fire resistance period.
It should also check that later M&E work has not damaged completed fire stopping.
Photographic evidence should show the wider location as well as the finished detail. Records should identify the penetration, system used, product, installer, inspection date and relevant drawing or reference.
A close-up of sealant without context is weak evidence. The record should allow someone unfamiliar with the project to understand what was installed and where.
Create a Penetration Register
For larger or more complex projects, a penetration register provides a clear way to manage the work.
Each penetration can be assigned a unique reference linked to its location, service type, substrate, required resistance period, approved system, installer record, photographs and inspection status.
This makes defects easier to track and evidence easier to retrieve. It also supports handover and future maintenance, particularly where the building falls within more demanding information management requirements.
The register should be updated as the work progresses. It is not something to reconstruct at the end from scattered photographs and site notes.
A reliable record is built alongside the installation.
Plan for Future Services
Buildings change after handover.
Additional cables are installed. Plant is replaced. Pipework is altered. New systems are added. If service routes and penetration zones are poorly planned, future work may damage compartmentation or create unrecorded openings.
Designated service zones and accessible penetration seals can reduce this risk. Spare capacity should be managed carefully and only where the tested system permits it. Access routes should allow future inspection without dismantling large parts of the building.
Facilities teams should receive clear information about which walls and floors are fire-resisting, where penetrations are located and what rules apply when services are altered.
The fire protection plan should consider the next intervention, not only practical completion.
Practical Pre-M&E Fire Protection Checklist
Before M&E installation begins, principal contractors should confirm that:
- Compartment walls, floors, risers and protected routes are clearly identified.
- Proposed service routes have been reviewed against the fire strategy.
- Planned penetrations are shown on coordinated drawings.
- Opening sizes and locations suit the proposed tested systems.
- Mixed service penetrations are covered by appropriate evidence.
- Sufficient working and inspection access has been allowed.
- Passive fire protection specialists have reviewed complex details.
- Temporary fire protection requirements have been agreed.
- Responsibility for forming, sealing, inspecting and recording openings is clear.
- Change control is in place for revised service routes.
- Inspection hold points are included before concealment.
- A penetration register or equivalent evidence system is ready for use.
These checks are modest compared with the cost of reopening finished work.
Why Early Planning Matters
Retrofitting passive fire protection around completed M&E installations is rarely elegant.
The result is often restricted access, complex remedial details, additional product, delayed ceilings, repeated inspection and uncertainty about whether the final arrangement remains within the tested evidence.
Early planning removes much of that difficulty.
It allows service penetrations to be designed rather than discovered. It gives installers room to work. It makes inspection possible. It reduces damage by later trades and creates a clearer evidence trail.
Most importantly, it keeps the compartmentation strategy intact as the building becomes more complex.
Why JW Simpkin Plans Around the Whole Assembly
At JW Simpkin, passive fire protection is considered as part of the construction sequence, not as a finishing exercise.
The opening, substrate, service, seal, barrier, fixing and surrounding construction form one assembly. Each part affects the others. Planning must therefore begin before the services occupy the space and before access disappears.
Early coordination allows tested systems to be selected properly, difficult details to be resolved and completed work to be inspected before concealment. It also gives principal contractors a clearer route from the fire strategy to the finished installation.
The value is not in adding more material at the end. It is in avoiding the need to improvise at all.
Conclusion: Give Fire Protection Its Place in the Programme
M&E installation gives a building its services. Passive fire protection ensures those services do not weaken the building’s fire-resisting structure.
The two packages cannot be planned separately.
Compartment lines need to be identified before routes are fixed. Penetrations need to be designed before holes are formed. Tested systems need to be selected before services are crowded into openings. Installation and inspection need space in the programme before ceilings, risers and walls are closed.
The principle is direct: plan the fire protection before the M&E installation begins.
Once the services are in place, the building has already made many of its decisions.