Most purpose-built blocks of flats rely on protection you never see. Walls, floors and doors are designed to keep a fire in the place where it started. This is called compartmentation, and it needs looking after.
What compartmentation means
A compartment is a part of a building bounded by walls and floors that will resist the passage of fire for a set period. In a purpose-built block, each flat is designed to work as its own fire-resisting enclosure.
National guidance explains that this should limit fire spreading from a flat to the escape routes, from flat to flat, and through routes such as concealed voids, service risers, ducts and lift shafts.
Why it matters for stay put
Stay put is the principle that, in many blocks, people in flats away from a fire can safely remain where they are unless they are affected by heat or smoke or told to leave. It depends on compartmentation working as designed.
Not every building has a stay-put strategy, so check the fire action notice and instructions for your block. Do not rely on a general article, including this one.
How it gets damaged
Compartmentation is rarely destroyed all at once. More often, it is weakened by small changes over the years:
- new pipes, cables or ducts run through walls or floors, with gaps left unsealed
- a fire-rated flat entrance door replaced with an ordinary one
- door closers removed or disconnected
- loft or riser hatches left open or replaced with unsuitable ones
- alterations inside a flat that cut into walls or ceilings between homes
What residents can do
- Keep your flat entrance door in good repair and never disconnect its closer.
- Get advice before making changes that affect your front door, walls between flats, floors or ceilings. Check your lease as well, because consent may be required.
- Tell contractors to seal around any new pipes or cables properly.
- Report damaged fire doors, missing seals or open riser cupboards.
Fire door checks in taller blocks
Where a building with two or more homes has a top storey above 11 metres, the Fire Safety (England) Regulations 2022 require the Responsible Person to:
- check communal fire doors at least every three months
- use best endeavours to check flat entrance fire doors at least every 12 months
- check that self-closing devices work
- keep records of the steps taken, including attempts to gain access
In buildings of any height with two or more homes and common parts used for evacuation, residents must be told how fire doors should be used. That means keeping them shut when not in use, leaving self-closers alone and reporting faults immediately.
For directors and those running a building
Your fire risk assessment should be the starting point. Keep a record of works that go through walls and floors, make sure contractors know that fire-stopping matters, and ask for evidence that the work has been done properly. If a concern is raised, ask a competent person to inspect it.
This guide is general information for England at 1 November 2026, not legal advice. Your lease and your building's circumstances may change how it applies to you, and the law may change after this date.