How to Maintain Accurate Fire Compartmentation Maps

Fire compartmentation is the division of a building into discrete fire-resistant cells that prevent the spread of fire and smoke from one area to another for a specified period. It is one of the most fundamental principles of passive fire protection, and its integrity is essential for the safe evacuation of occupants, the protection of property, and the operational effectiveness of the fire service. Yet compartmentation is also one of the most commonly compromised fire safety measures in existing buildings — eroded over years of building modifications, service installations, and maintenance work that penetrate fire-resisting walls and floors without adequate fire stopping. This guide provides a practical framework for understanding, surveying, mapping, and maintaining fire compartmentation using floorplan-based digital systems, with specific reference to UK regulatory standards.

Table of Contents

• •What Is Fire Compartmentation
• •Regulatory Framework
• •Compartment Types
• •Fire Stopping and Penetration Seals
• •Compartmentation Survey Methodology
• •Mapping Compartmentation on Floorplans
• •Breach Tracking
• •Remediation Workflows
• •Common Failures
• •Digital Compartmentation Management
• •Key Takeaways
• •Frequently Asked Questions
• •Next Steps

What Is Fire Compartmentation

Fire compartmentation is the strategy of dividing a building into separate compartments using fire-resisting construction — walls, floors, doors, and closures — so that a fire originating in one compartment is contained within that compartment for a defined period, typically 30, 60, or 120 minutes depending on the building type, height, and use. The purpose is threefold: to provide occupants in adjacent compartments with time to evacuate (or to remain safely in place under a defend-in-place strategy), to limit the total fire size and thereby protect the building structure and neighbouring properties, and to provide the fire service with manageable fire zones from which to mount a firefighting operation.

A fire compartment is defined as a building or part of a building comprising one or more rooms, spaces, or storeys, constructed to prevent the spread of fire to or from another part of the same building or an adjoining building. The compartment boundaries — walls, floors, and the elements that penetrate them (doors, ducts, pipes, cables) — must collectively achieve the required fire resistance period. The failure of any single element (an unsealed pipe penetration, a damaged fire door, an unprotected duct opening) can compromise the entire compartment.

Compartmentation is a passive fire protection measure — it operates without human intervention or electrical power. Unlike active measures (sprinklers, fire alarms, smoke ventilation), which require activation and ongoing energy supply, compartmentation is inherent in the building's physical construction. This makes it both highly reliable when intact and highly vulnerable when modified without appropriate fire protection reinstatement.

Regulatory Framework

The regulatory requirements for fire compartmentation in the UK derive from several key instruments:

Building Regulations 2010 — Approved Document B provides prescriptive guidance on compartmentation requirements based on building purpose group, height, and floor area. Key provisions include:

• •Compartment sizes — Maximum compartment floor areas and building heights are specified for each purpose group. For example, residential buildings require each dwelling to be a separate compartment; office buildings over 2,000 square metres may require sub-division; and industrial/storage buildings have compartment size limits based on height and whether sprinklers are fitted.
• •Fire resistance periods — The required fire resistance of compartment walls and floors depends on the building purpose group, height, and whether the element is a loadbearing structure. Typical periods are 30 minutes for residential buildings up to 5 metres, 60 minutes for buildings 5-18 metres, and 120 minutes for buildings over 18 metres.
• •Separating walls — Walls between different occupancies (e.g., between a shop and the flat above) must be compartment walls with the specified fire resistance period.

In Ireland, Technical Guidance Document B (TGD B) supporting Part B of the Building Regulations sets out comparable compartmentation requirements, with compartment sizes and fire resistance periods determined by building purpose group, height, and floor area. TGD B aligns closely with the UK's Approved Document B in its prescriptive approach, though specific dimensional limits and fire resistance periods may differ. The Fire Services Acts 1981 and 2003 require the person having control of premises to maintain fire safety measures, including compartmentation, in a condition that guards against fire spread.

BS 9999:2017 provides an alternative, risk-based framework for determining compartment sizes and fire resistance periods, allowing designers to justify larger compartments or reduced fire resistance where compensating features (sprinklers, enhanced detection, managed evacuation) are present.

The Regulatory Reform (Fire Safety) Order 2005 requires the responsible person to maintain fire safety measures, including compartmentation, in the existing building. While the Fire Safety Order does not prescribe specific fire resistance periods (these are established at the design and construction stage), it requires that the as-built compartmentation is maintained in effective working order.

The Building Safety Act 2022 introduces enhanced requirements for higher-risk buildings, including the obligation to maintain a comprehensive record of the building's fire safety features — including compartmentation — and to manage changes that could affect fire safety performance.

The Fire Safety (England) Regulations 2022 specifically require the responsible person for multi-occupied residential buildings with storeys over 11 metres to provide information about the building's external wall construction and compartmentation to the fire and rescue service.

Compartment Types

Fire compartmentation takes several physical forms, each serving a specific function within the building's fire strategy:

Fire Walls (Compartment Walls)

Vertical fire-resisting elements that divide the building into separate compartments on the same floor. Compartment walls must extend the full height from floor slab to the underside of the roof covering (or the floor slab above) and be constructed of materials and assemblies that achieve the required fire resistance period when tested to BS 476-21 or BS EN 1364-1.

Fire Floors (Compartment Floors)

Horizontal fire-resisting elements that divide the building into separate compartments at different levels. In most multi-storey buildings, every floor is a compartment floor, preventing fire spread from one storey to the next. The floor construction, including any structural elements supporting it, must achieve the required fire resistance period.

Protected Shafts

Vertical enclosures that pass through compartment floors — stairways, lift shafts, service risers, and ventilation ducts. Because these shafts create pathways between compartments, they must be enclosed by fire-resisting construction to the same standard as the compartments they pass through. Protected shafts are one of the most common locations for compartmentation breaches, as they attract service installations (pipes, cables, ducts) that require careful fire stopping.

Cavity Barriers

Elements installed within concealed spaces (above suspended ceilings, within wall cavities, in roof voids) to prevent the unseen spread of fire and smoke through these hidden pathways. Cavity barriers must be provided at the junction of every compartment wall and compartment floor with the cavity, and at specified maximum intervals within extended cavities.

Fire-Resisting Doors and Closures

Every opening in a compartment wall or floor (doors, hatches, ducts, conveyors) must be protected by an element that achieves the required fire resistance. For personnel doors, this means fire-rated door assemblies with appropriate intumescent strips, smoke seals, and self-closing devices. Our Fire Door Inspection Workflow article covers the maintenance requirements for these critical components.

Service Penetrations

Any pipe, cable, duct, or other service that passes through a compartment wall or floor creates a penetration that must be sealed with an appropriate fire stopping system to maintain the compartment's fire resistance. This is the single most common source of compartmentation failure.

Fire Stopping and Penetration Seals

Fire stopping refers to the products and systems used to seal openings and penetrations in fire-resisting construction. The objective is to restore the fire resistance of the compartment element to its original rated period after a penetration has been made. Fire stopping products include:

• •Intumescent sealants and mastics — Applied around small cable and pipe penetrations. These products expand when exposed to heat, sealing the gap and insulating the penetrating service.
• •Intumescent wraps and collars — Fitted around plastic pipes that pass through compartment walls or floors. When exposed to fire, the wrap or collar constricts, crushing the melting pipe and sealing the opening.
• •Fire pillows and bags — Used to seal service penetrations in risers and floor voids where services may need to be added or modified in the future. They provide a removable, reconfigurable fire seal.
• •Fire batts and boards — Mineral fibre or calcium silicate boards used to seal larger openings, such as around cable trays or at the top of compartment walls that terminate at a suspended ceiling.
• •Fire-resistant ductwork and dampers — Ducts that pass through compartment walls or floors must either be fire-rated ductwork or fitted with fire dampers that close automatically when exposed to heat or triggered by the fire alarm system.

All fire stopping products must be tested and certified to the relevant standards (BS 476 or BS EN 1366) for the specific application — the pipe diameter, pipe material, wall or floor type, and penetration configuration. A fire stopping product that is certified for a 100mm steel pipe through a concrete floor may not be appropriate for a 100mm plastic pipe through a plasterboard partition. Incorrect product selection is a common and serious error.

Installation must be carried out by competent persons — ideally holding third-party certification (e.g., through the IFC Certification, FIRAS, or similar schemes) — and the installation must be documented with photographs, product data sheets, and test evidence.

Compartmentation Survey Methodology

A compartmentation survey is a systematic inspection of the building's fire-resisting construction to verify that compartment boundaries are intact and that all penetrations are adequately fire-stopped. The survey typically follows this process:

Desktop Review

1. Obtain the original building drawings, fire strategy documents, and any subsequent modification records.
2. Identify the compartment boundaries from the drawings — compartment walls, compartment floors, protected shafts, and cavity barrier locations.
3. Review any previous fire risk assessments, compartmentation survey reports, and remediation records.
4. Prepare a survey plan identifying the areas to be inspected and the access requirements (some compartment elements are concealed above suspended ceilings or within wall cavities).

On-Site Inspection

The on-site survey examines each compartment boundary for:

• •Unsealed penetrations — Cables, pipes, and ducts passing through compartment walls or floors without fire stopping. This is the most common finding.
• •Failed or missing fire stopping — Fire stopping products that have been removed, damaged, or incorrectly installed. Check for gaps around fire stopping installations, products that have been painted over (which can affect performance), and installations that do not match the product's tested configuration.
• •Damaged compartment construction — Holes, cracks, or openings in compartment walls or floors that have not been sealed. Common at the junction of partition walls with the structural slab and at points where building modifications have been made.
• •Missing cavity barriers — Above suspended ceilings and within wall cavities at compartment boundary locations. These require removal of ceiling tiles or inspection hatches for verification.
• •Fire door deficiencies — As part of the compartment boundary, every fire door must be assessed for compliance. Cross-reference with the fire door inspection programme.
• •Duct penetrations — Verify that fire dampers are present at every point where a duct passes through a compartment boundary, that the dampers are accessible for inspection and testing, and that they are functional.

Documentation

Each finding should be recorded with:

• •The location (referenced to the floorplan).
• •A photograph of the deficiency.
• •The compartment boundary affected.
• •The severity assessment (critical, high, medium, low).
• •The recommended remediation.

Mapping Compartmentation on Floorplans

Mapping compartmentation boundaries on floorplans transforms the survey data from a list of findings into a spatial model of the building's passive fire protection. This approach provides several critical advantages:

• •Visual representation of compartment boundaries — Drawing compartment walls and floors on the floorplan creates a colour-coded overlay that shows the extent of each fire compartment. Stakeholders can immediately see how the building is divided and understand which areas are protected from which.

• •Penetration location tracking — Every penetration through a compartment boundary (pipe, cable, duct) is plotted on the floorplan at its exact location, with the fire stopping status recorded: sealed (with product details and certification), unsealed (deficiency requiring remediation), or unknown (requiring inspection).

• •Coverage analysis — The floorplan view reveals areas where compartment boundaries have not been surveyed, enabling the survey programme to be targeted at gaps in coverage rather than re-inspecting previously surveyed areas.

• •Trend analysis — Over time, the accumulation of breach data on the floorplan reveals patterns: floors or zones where breaches concentrate, service risers that are repeatedly penetrated without reinstatement, or building modification programmes that consistently fail to reinstate fire stopping.

Plotstuff, as modern spatial infrastructure software, provides the tools to draw compartment boundaries on uploaded floorplans, plot penetration points with structured data fields, and generate reports that combine spatial and tabular information. This is materially different from marking up a PDF or CAD drawing — the data behind each boundary and penetration point is structured, searchable, and linked to the inspection and remediation history.

Breach Tracking

A compartmentation breach is any opening, penetration, or deficiency in a compartment boundary that reduces its fire resistance below the required period. Breach tracking is the process of identifying, recording, prioritising, and monitoring breaches through to remediation.

Breach Classification

• •Critical — A breach that could allow rapid fire or smoke spread between compartments and poses an immediate risk to life safety. Examples: a large unsealed opening through a compartment wall in a residential building, a missing fire damper in a main ventilation duct, or a fire door that cannot close.
• •High — A breach that significantly degrades the compartment's fire resistance but may not pose an immediate life-safety risk. Examples: multiple unsealed cable penetrations in a commercial building, a damaged intumescent collar around a plastic soil pipe, or a compartment wall that terminates at a suspended ceiling rather than extending to the structural slab.
• •Medium — A breach that partially degrades the compartment's fire resistance. Examples: a small unsealed cable penetration, a fire stopping product that is deteriorating but still substantially intact.
• •Low — A minor deficiency that should be addressed but does not significantly affect compartment performance. Examples: aesthetic damage to fire stopping products, minor sealant shrinkage around a well-packed penetration.

Tracking Requirements

Each breach record should include:

• •Unique identifier.
• •Location on the floorplan.
• •Compartment boundary affected (identified by reference).
• •Breach type (unsealed penetration, damaged construction, missing fire stopping, failed fire damper, etc.).
• •Severity classification.
• •Photograph(s).
• •Date identified.
• •Assigned remediation responsibility.
• •Target remediation date.
• •Actual remediation date.
• •Post-remediation verification (by whom, date, photograph).

Remediation Workflows

Remediation of compartmentation breaches requires a systematic workflow:

1. Prioritisation — Address critical and high-priority breaches first. Where immediate remediation is not possible, implement interim measures (fire watches, temporary sealing, enhanced detection).

1. Specification — Each breach requires a remediation specification that identifies the appropriate fire stopping product and installation method for the specific penetration type, size, and construction. This must be based on tested and certified configurations, not generic product application.

1. Contractor selection — Fire stopping installation should be carried out by competent contractors, preferably holding third-party certification. The responsible person should verify contractor competence before work commences.

1. Installation — The fire stopping product is installed in accordance with the manufacturer's instructions and the tested configuration. The installer should photograph the completed installation from a consistent angle.

1. Verification — A competent person (not the installer) verifies the completed installation against the specification, checking product type, installation quality, and conformity with the tested configuration. The verifier should photograph the verified installation.

1. Record update — The breach record on the floorplan is updated with the remediation details: date completed, contractor, product used, installer, verifier, and photographs. The breach status changes from "open" to "remediated."

1. Audit — Periodic audits of remediated breaches verify that the fire stopping remains in place and in good condition, and that new breaches have not been created adjacent to previously remediated areas.

This workflow creates a closed loop from identification through remediation to verification, with every step documented and spatially referenced on the floorplan.

Common Failures

Analysis of compartmentation surveys consistently reveals the same categories of failure:

Service Penetrations

The most prevalent compartmentation failure. Every time a cable, pipe, or duct is routed through a compartment wall or floor, the penetration must be fire-stopped. In practice, service installations — particularly by electrical contractors, plumbing contractors, and data cabling installers — frequently penetrate compartment boundaries without reinstating fire stopping. This occurs during original construction, during refurbishment, and during routine maintenance and upgrades.

The problem is exacerbated in service risers, where multiple penetrations accumulate over the building's life, and in ceiling voids, where penetrations are concealed and unmonitored.

Building Modifications

Refurbishment and modification projects frequently involve alterations to compartment boundaries — removing walls, creating new openings, installing new services — without adequate fire stopping reinstatement. This is particularly common when:

• •The design team is unaware of the location of compartment boundaries.
• •Fire stopping is treated as a "final fix" item that is omitted when the project runs over budget or schedule.
• •The building's fire strategy is not reviewed as part of the modification project.

Degradation Over Time

Fire stopping products can degrade through:

• •Physical damage (impact, abrasion, removal during maintenance work).
• •Environmental exposure (moisture, chemical exposure, UV degradation for some products).
• •Thermal cycling (expansion and contraction of services and structure).
• •Ageing of sealant and mastic products (hardening, cracking, loss of adhesion).

Cavity Barrier Omissions

Cavity barriers are frequently omitted or incorrectly installed, particularly:

• •Above suspended ceilings at compartment wall junctions.
• •Within wall cavities in timber-frame and steel-frame construction.
• •In roof voids at compartment wall junctions.

These omissions create concealed pathways for fire and smoke spread that are invisible from the building interior and can allow fire to bypass compartment boundaries entirely.

Fire Damper Failures

Fire dampers in ductwork — essential for maintaining compartmentation where ventilation systems cross compartment boundaries — are subject to:

• •Mechanical failure (rust, seized mechanisms, broken fusible links).
• •Obstruction (debris, insulation, or construction materials preventing closure).
• •Inaccessibility (dampers installed without adequate access for inspection and testing, making maintenance impracticable).

BS 9999 and HTM 05-02 (for healthcare premises) require periodic testing of fire dampers — typically annually — to verify closure and reset operation.

Digital Compartmentation Management

Digital compartmentation management using floorplan-based systems represents a fundamental improvement over traditional survey-and-report approaches:

• •Living documentation — Rather than a static survey report that becomes outdated as soon as the next building modification occurs, a digital system maintains a continuously updated record of compartment boundaries, penetrations, fire stopping status, and breach history.

• •Change management integration — When building modifications are proposed, the impact on compartmentation can be assessed before work begins, and the fire stopping requirements can be specified as part of the project scope.

• •Contractor management — Fire stopping contractors can access the floorplan system to view the penetrations assigned to them, upload installation photographs, and record the products used — providing real-time visibility of remediation progress.

• •Regulatory reporting — The structured data in the system supports the preparation of fire safety information required by the Fire Safety (England) Regulations 2022, the Building Safety Act Safety Case, and insurance surveys.

• •Integration with other fire safety systems — Compartmentation data on the floorplan connects with fire door inspection data, fire safety asset locations, and evacuation route definitions, providing a holistic view of the building's fire safety performance.

Modern spatial infrastructure software like Plotstuff provides the platform for this approach, combining floorplan upload, boundary drawing, penetration plotting, inspection workflow, remediation tracking, and reporting in a single, auditable system.

Key Takeaways

• •Fire compartmentation divides buildings into fire-resistant cells using walls, floors, doors, and closures, providing time for evacuation and containing fire spread. Its integrity is essential for life safety.
• •Regulatory requirements under Building Regulations Part B, BS 9999, the Fire Safety Order, and the Building Safety Act establish both the design standards and the ongoing maintenance obligations for compartmentation.
• •Fire stopping — the sealing of penetrations through compartment boundaries — is the most commonly deficient element, with unsealed service penetrations found in the majority of existing buildings.
• •Compartmentation surveys must be systematic, covering walls, floors, shafts, cavity barriers, fire doors, and fire dampers, with every finding documented by location, photograph, severity, and recommended remediation.
• •Mapping compartmentation on floorplans provides spatial context that transforms breach data from a list into an actionable model of the building's passive fire protection.
• •Remediation requires a closed-loop workflow from breach identification through specification, installation, verification, and record update.
• •Common failures — service penetrations, building modifications, degradation, cavity barrier omissions, and fire damper failures — are predictable and preventable with systematic management.

Frequently Asked Questions

How often should a compartmentation survey be conducted?

There is no single mandated frequency. Best practice is to conduct a comprehensive baseline survey, then repeat the survey at intervals determined by the building's risk profile and modification activity — typically every 3-5 years for higher-risk buildings and following any significant building modification. Continuous monitoring through the building's change management process reduces the need for repeated full surveys.

Who is competent to conduct a compartmentation survey?

A compartmentation surveyor should have detailed knowledge of fire-resisting construction, fire stopping products and their tested applications, the relevant standards (Building Regulations Part B, BS 9999, BS 476, BS EN 1366), and the ability to assess whether an installation meets the tested and approved configuration. Third-party certification (e.g., through IFC Certification or FIRAS) provides assurance of competence.

What is the difference between fire stopping and fire proofing?

Fire stopping specifically refers to the products and systems used to seal openings and penetrations in fire-resisting construction — maintaining compartmentation around pipes, cables, and ducts. Fireproofing (or fire protection) is a broader term that encompasses the application of fire-resistant materials to structural elements (steel beams, columns) to protect them from premature collapse during a fire. Both are passive fire protection measures, but they address different aspects of the building's fire resistance.

Can I use general-purpose sealant for fire stopping?

No. Fire stopping must be achieved using products that have been specifically tested and certified for fire resistance in the specific application. General-purpose silicone, acrylic, or polyurethane sealants do not provide fire resistance and will fail almost immediately in a fire. Using uncertified products as fire stopping is a serious compliance failure.

How does compartmentation relate to fire doors?

Fire doors are integral components of fire compartmentation. Every doorway through a compartment wall is a potential weak point — an opening that must be protected by a fire-rated door assembly to maintain the compartment's fire resistance. A compartment wall with a failed fire door (one that cannot close, has missing seals, or has excessive gaps) is a compromised compartment. See Fire Door Inspection Workflow for the detailed inspection and maintenance requirements.

Next Steps

Begin by obtaining or creating accurate floorplans for your building portfolio and identifying compartment boundaries from the original design documentation. Commission a baseline compartmentation survey to assess the current state of fire stopping across all compartment boundaries. Use a floorplan-based digital system to map compartment boundaries, plot penetrations, track breaches, and manage remediation workflows. Integrate compartmentation management with your broader fire safety asset management programme to create a comprehensive, spatially referenced view of your building's passive and active fire protection.

For related guidance, see our articles on Fire Door Inspection, Fire Safety Assets, and Evacuation Route Planning.