What a Compartmentation Survey Finds: Results From 407 Locations

What did our compartmentation surveys find?

371 of the 407 locations we checked needed fire stopping, which is 91%. The two surveys were a 5-storey hotel with sleeping accommodation and a restaurant.

Two surveys is a small sample, and we will add to this page as more are completed. Locations are individual points such as a pipe or cable passing through a wall or floor, a riser opening or a ceiling junction. Figures are from DC Fire & Security's own survey reports. Client names are left out.

What is a compartmentation survey?

It is a check that the fire-resisting walls, floors and ceilings in a building form unbroken compartments, so fire and smoke cannot spread through hidden gaps. The surveyor looks for breaches, records each one with a photo and a location, and lists what is needed to seal it.

A non-intrusive survey looks at what can be seen. An intrusive survey opens up ceilings, boxing and riser enclosures where the barrier cannot be seen. The right level depends on the building. Our compartmentation survey service covers both.

Where do the gaps usually turn up?

Where something has been added after the building was finished: cables, pipes and ducts passing through walls and floors, risers, and the space above suspended ceilings.

• Cables and pipes passing through fire walls and floors with no fire stopping, or the wrong sealant
• Riser cupboards and service shafts open at floor level
• Gaps between the top of a fire wall and the slab above a false ceiling
• Missing or damaged cavity barriers
• Fire doors in the compartment line that do not close or seal, see fire door inspections

What happens after the survey?

You get a report with every breach photographed, numbered and ranked by risk. The sealing work is then priced from that list, so you pay for the locations that need work, not an estimate for the whole building.

Fire stopping is done with tested products fitted to the manufacturer's method, and each seal is recorded. We cover this under fire stopping. Because we survey fire doors as well, the doors and the walls round them can be handled together.

Who has to arrange one?

The responsible person for the building, under the Regulatory Reform (Fire Safety) Order 2005. In practice that is the landlord, employer, managing agent or owner.

The Order requires the responsible person to keep the fire protection in the building in good order. A fire risk assessment may recommend a compartmentation survey where it could not see the barriers. Where an assessment says compartmentation was checked only where it could be seen, a survey closes that gap.

Sources

• Regulatory Reform (Fire Safety) Order 2005 (legislation.gov.uk)
• Approved Document B: Fire safety (GOV.UK)
• Fire Safety Act 2021 (legislation.gov.uk)

Updated October 2026 by Sebastian Grabowski, DC Fire & Security. We survey compartmentation and fire stopping, and inspect and repair fire doors, across Bedfordshire, Hertfordshire, London, the Thames Valley and the East Midlands.