Steel Staircase Fire Rating Basics for Commercial Buildings

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A steel staircase fire rating describes how long the staircase assembly can keep its structural integrity and protect escape routes during a fire. It depends on the steel members, the fire protection applied to them, and how the stair connects to the rest of the building. Building managers should confirm the required rating with the project engineer and the local fire authority before ordering.

What a fire rating means for a steel stair

A fire rating tells you how long a building element can withstand standard fire exposure while performing its job. For a staircase, the key job is keeping people able to escape safely. The rating is not a property of steel alone, because bare steel loses strength quickly when heated.

When managers talk about a steel staircase fire rating, they usually mean the rating of the complete assembly, including treated steel members, any enclosure, and the connections that tie the stair to walls and floors.

Components that affect the rating

Several parts of a steel stair contribute to its fire performance:

Stringers, treads, landings and supporting beams
Fire protection materials such as intumescent coatings or board systems
Enclosure walls and doors around the stair shaft
Fixings and connections to the building structure

Each part needs to be considered together, since a weak connection can undermine an otherwise well-protected member.

Why protection matters for steel

Unprotected steel can lose a large share of its load-bearing capacity under fire conditions, which is why most commercial projects specify a protective system. The required thickness or type of protection depends on the target rating and the section size of each member.

Exact protection values are determined by the engineer for each project, using the applicable codes and tested assembly data rather than general rules of thumb.

Checking the rating on a project

Before ordering, managers should ask for documentation that links the proposed stair to a tested or engineered assembly. This usually includes drawings showing the protection layout and a written statement of the rating achieved.

Confirm the required rating for the building class and use
Request the protection specification in writing
Check that enclosure and door ratings match the stair

Escape routes and building regulations

Staircases are part of the means of escape, so their fire performance is reviewed alongside other safety features such as signage, lighting, and fire doors. Local rules and the Israeli standards for fire safety set the framework, and the fire authority may have specific requirements for your building.

Early coordination with the architect, engineer and fire consultant avoids costly changes after installation.

Working with a manufacturer

A reliable manufacturer will explain how the stair is protected, which components are treated, and what documentation can be provided. At Techno Kol Uzi, the process starts with a site measurement, then a drawing and written specification that the client approves before production in our Tel Aviv factory.

Finishing such as hot-dip galvanizing or powder coating is planned as part of that specification, so the protection requirements are reviewed at the design stage.

Frequently asked questions

Is a steel staircase fire rated by default?

Not necessarily. Bare steel needs a protection system or an engineered assembly to achieve a specific fire rating, so the rating must be confirmed for each project.

Who decides the required fire rating?

The required rating is set by building codes and the fire authority, based on building class and use. The project engineer then designs the protection to meet it.

Does galvanizing provide fire resistance?

Galvanizing mainly protects against corrosion and does not by itself provide fire resistance. Fire protection is a separate measure that must be specified and confirmed.

What documents should I ask for?

Ask for the drawings, the written protection specification, and documentation linking the assembly to a tested or engineered rating. Keep these with the building records.

Common mistakes to avoid

A common mistake is assuming a steel stair is fire rated without written confirmation of the protection system. Another is ordering the stair before the enclosure and door ratings are checked against it.

Our recommendation

Involve the structural engineer and fire consultant before the stair is designed, and request the fire protection specification in writing as part of the approved drawings.

Summary

Steel staircase fire rating depends on the members, their protection, and the connections, and it must be confirmed in writing for each commercial project.

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