Interior barriers work by delay and by channelling people through one controlled route: choose a refuge room with the fewest exterior walls, give it a solid door and a second way out, and let only one stairway stay open in a multi-storey building. An ordinary interior wall is hollow and light and stops nothing by itself, and any barricade must be removable from the inside so that it does not trap the people it is meant to protect.
Interior barriers are the doors, walls and obstructions added inside a building so that a breach of the outside does not give free access to every room.
Delay, Not Cover
The parent article recommends a central safe room (the room with the fewest exterior walls, such as an interior bathroom or closet), reinforcement of its walls and door, stocked water and supplies, and a concealed exit. It also suggests treating a stairwell as a natural choke point: barricade all but one stairway and block the remaining one with removable barriers.
That is the right idea if it is understood as delay and control of movement. A barrier inside a building gives time to leave, to raise the alarm or to reach the refuge. It does not make the room safe against everything. Ordinary interior partitions of boards, lath or thin plaster are hollow and light; they hide, but do not resist. If you want a wall that does more, it has to be heavy, and the ballistic table in Defensive Architecture says its figures are untested and its light rows unproven. Name the threat and treat any protection figure as unproven.
What You Need
- A room chosen for position. Fewest exterior walls, no large windows, away from the kitchen and any fuel or stove.
- A solid door and frame. See Window and Door Hardening for fixing a frame properly and for the bar.
- A second exit. The parent article calls it concealed; it must also be usable by children and the injured, from the inside, without tools.
- Water and sanitation. The safe-room figures in Defensive Architecture apply (20 litres per person per day).
- A way to signal and be signalled. A prearranged knock or code to tell occupants the danger has passed.
- Floor strength. If you add mass, check the floor; see the arithmetic in Window and Door Hardening.
Method: Make A Refuge And A Controlled Route
Step 1: Pick the room and empty it. Remove anything that burns easily or will become a hazard. Keep fuel, lamp oil and similar out. If you keep gasoline, Fire Prevention covers its vapour; it is not a general fire-safety page.
Step 2: Fit the door and the bar from the inside. The door opens inward or outward as the room permits, with fixings into the structure. One person must be able to open it from inside in the dark.
Step 3: Provide the second way out. A window openable from inside, a hatch, or a second door. Decide in advance where each person goes, as in Escape Route Planning.
Step 4: Control the stairs. In a multi-storey building, close all stairways but one with removable barriers (a bar across the stairhead, a stack that can be moved). The single open stair is where anyone moving between floors must pass, so it can be watched.
Step 5: Rehearse. Walk the family through entering, closing, barring, signalling and leaving by the second exit, in the dark, and time it.
Fire And The Barrier
A barricade stops people and also stops smoke leaving. A fire in the building can reach the refuge before help does. Use a non-combustible door if you can, keep the room free of fuel, know where the second exit leads, and keep water in the room. In a fire, leave: the refuge is for a threat from people, not for waiting out a burning building. Never block the only stair with a stack that cannot be moved from the stairwell side.
Common Mistakes
- A barricade that cannot be opened from inside. It becomes a trap in a fire.
- Choosing a bathroom beside the kitchen. Fire and fuel are next door.
- Heavy stacks on an upper floor. The floor may not carry them.
- A refuge with one exit. If the door is blocked or burning, there is no way out.
- Hiding supplies where occupants cannot reach them in the dark.
Locked in is the main risk
Barricades, bars and extra doors have trapped occupants in fires and in rooms where a door jammed. Every barrier must be removable from the inside by one person without tools. Do not seal a room with a stove or lamp burning, since carbon monoxide builds up unnoticed. Do not lock anyone, including an intruder, into a space from which they cannot get out.
What’s Next
- Learn next: Roof Reinforcement — protecting the top of the building
- Combine with: Escape Route Planning — where the second way out leads