What is a protected stairway?
A protected stairway is a stair enclosed in fire-resisting construction, forming a protected route from the floors it serves down to a final exit. In most buildings it is the critical escape route.
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<img src="https://fireoptix.co.uk/glossary/protected-stairway/diagram.svg" alt="protected stairway — diagram from FireOptix" width="880" height="620" loading="lazy">
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<a href="https://fireoptix.co.uk/glossary/protected-stairway">What is a protected stairway?</a> — diagram by
<a href="https://fireoptix.co.uk">FireOptix</a>
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</figure>It is critical because everyone above ground level uses it and there is usually no alternative. A stairway lost to smoke is not a degraded route; it is no route at all for the floors above the smoke.
For that reason it is kept clear of anything that could burn or obstruct, more strictly than a corridor. Furniture, storage and combustible materials in a protected stair are treated as serious findings rather than housekeeping.
Where a stair also serves as the firefighting route, it carries additional provisions. Those are design matters, but the practical consequence is that the same stair is being used in two directions at once.
In practice
A stairway used to store a vacuum cleaner and a box of files.
It is the only convenient space, the items are tidy, and nobody has ever been impeded.
A protected stairway is kept free of fire load because it is the one place people have to pass through, and small amounts of storage normalise into large amounts.
It is the most common finding in residential blocks and the most consistently minimised.
What goes wrong in practice
- Storage on landings or under the stair, which is both fuel and obstruction.
- Stair doors held open by wedges or by failed closers.
- Smoke ventilation to the stair blocked, disabled or never tested.