Overview
Compartmentation is designed to slow the spread of fire and smoke by maintaining fire-resisting lines through walls, floors, risers and voids.
A compartmentation survey is a structured inspection to identify breaches (often hidden or overlooked) and to produce a practical, prioritised remedial plan.
What “compartmentation” means (plain English)
Most buildings are designed so that fire and smoke are contained for a period within defined areas (compartments) using fire-resisting construction.
Typical compartmentation lines include:
- walls and floors between flats
- corridor and stair enclosures
- risers/shafts and plant areas
- protected routes and lobbies
The weak points are usually not the wall itself — it’s the interfaces: penetrations, junctions, access hatches, and changes introduced over years of refurb and M&E works.
When you should consider a compartmentation survey
- your fire risk assessment flags unknowns or likely breaches
- you’ve had multiple rounds of M&E/refit works across risers and ceilings
- you have repeated “reactive” fire stopping without a clear register
- you’re planning a remedial programme and need a scope you can procure against
What surveys typically look for
- service penetrations that are unsealed or sealed incorrectly
- defects in risers/shafts and around builders work openings
- gaps in ceiling voids and wall/floor junctions
- missing/damaged cavity barriers where relevant
Depending on scope and access, a survey may also cover:
- above-ceiling voids in corridors and lobbies
- behind riser cupboard linings and service boxing
- around dampers/ductwork penetrations
- loft/roof void fire separation (where relevant)
Non-intrusive vs intrusive surveys
Not every site needs “open everything”. A sensible approach is often phased:
-
Non-intrusive (visual) checks of accessible areas to identify patterns.
-
Targeted intrusive checks (lift tiles/open access panels/inspect sample areas) where the risk picture suggests hidden breaches.
Always agree what “intrusive” means up front (permissions, resident comms, making-good responsibilities).
What to prepare before a survey (to keep it efficient)
If you can provide these up front, the survey is usually faster and more accurate:
- any existing FRA, drawings, or previous compartmentation reports
- a list of risers/plant rooms and how they’re accessed
- known refurbishment history (especially M&E works)
- access permissions and escort requirements
If documentation is limited (common in older stock), a good survey can still proceed — it just needs clearer assumptions and more time on site.
What you should receive
A useful output is one you can action:
- defect register with locations
- priority and recommended next actions
- photo evidence where it helps clarity
- an approach for remedials that aligns to suitable, tested systems
We’d normally expect outputs to include:
- a defect register with clear locations (block/level/room/face)
- photos where they help clarity and close-out later
- defect priority and recommended next actions
- notes on access constraints and assumptions
- a recommended remedial approach that references suitable system types (so procurement is realistic)
Outputs checklist
| Output | Why it matters |
|---|---|
| Defect register with stable IDs | Makes re-checks and close-out possible |
| Precise locations | Turns a report into a priced scope |
| Priorities | Supports programme planning and risk management |
| Photos (where practical) | Reduces disputes and improves close-out |
| Constraints/exceptions | Prevents false confidence |
| Remedial approach/system types | Keeps procurement realistic and defensible |
How it works
- Define scope — which blocks/risers/voids/areas and what level of intrusiveness.
- Inspect and record — consistent defect categories and location references.
- Prioritise — risk-based triage for urgent vs planned remedials.
- Turn findings into a scope — packages that a contractor can price fairly.
- Close out — remedials recorded against the register for an auditable trail.
FAQs
Is a compartmentation survey the same as a fire risk assessment?
No. An FRA is a broader assessment of fire risk and management arrangements. A compartmentation survey is typically a more detailed, location-specific inspection focused on passive fire-resisting lines and breaches.
Do we need 100% intrusive access?
Not usually. A phased, targeted approach is often more proportionate: start with accessible areas, then agree intrusive sampling where it will materially change the risk picture.
What makes a survey “actionable”?
Clear locations, clear defect descriptions, priorities, and a remedial approach that references suitable systems. If a report can’t be turned into a priced scope, it’s rarely useful.