Fire Protection for Structural Steel in the UAE: Ratings, Systems and Approvals

Structural steel does not burn, which is exactly why its fire behaviour is misunderstood. The problem is not combustion — it is that steel softens. By around 550 °C a typical structural grade has lost roughly half its room-temperature yield strength, and a member designed with normal safety factors is approaching the load it can no longer carry.

Fire protection buys time: enough for occupants to leave and for the fire service to work. In the UAE, how much time, and by what means, is governed by the UAE Fire and Life Safety Code, which drives both the required ratings and the approval of the materials used.

What a fire rating means

A rating is expressed in minutes — 60, 90, 120 minutes and so on. It is the period for which the protected element must continue to perform in a standard fire test. The required period depends on the building's occupancy, height, compartmentation and the role of the member: transfer structures and columns supporting several floors typically demand more than secondary beams.

Two things follow that surprise people new to the subject:

• The rating applies to the element, not the product. A coating does not have a "120 minute rating" in isolation. It achieves 120 minutes at a stated thickness on a member of a stated section factor.
• Section factor drives thickness. A slender member with a high exposed-perimeter-to-area ratio heats faster and needs more protection than a chunky one for the same rating.

Section factor in one sentence

Section factor (Hp/A, or A/V) is the heated perimeter divided by the cross-sectional area — high value means thin and fast-heating, low value means massive and slow. Every protection system's thickness schedule is a table indexed against it, which is why the fire engineer needs your final member sizes before thicknesses can be fixed.

The three main systems

Intumescent coating

A paint-like coating that, on heating, expands into an insulating char many times its applied thickness.

• Strengths: follows the profile of the steel, so it suits exposed architectural steelwork; can be applied off site in the fabrication shop, which removes a trade from the site programme; thin.
• Watch: thickness must be verified by wet and dry film gauge readings and recorded; it needs a compatible primer and usually a topcoat; overcoating windows and cure times are real programme constraints; damage in transit and erection requires touch-up procedures.

Board systems

Calcium silicate or gypsum-based boards fixed around the member.

• Strengths: robust, clean boxed appearance, thickness is easy to verify by measurement, tolerant of site handling.
• Watch: boxes the section, so it hides the steel profile; labour intensive; junctions and penetrations need detailing.

Sprayed cementitious / vermiculite

• Strengths: fast to apply over large areas, economical for concealed steel, high ratings achievable.
• Watch: rough finish, so it is for concealed conditions; wet trade on site; overspray protection required; thickness verification by depth gauge on a sampling regime.

Local approval is not a formality

The single most common programme failure on this subject: a product is specified on the basis of a test certificate from another market, and is then found not to hold the required UAE approval. The Fire and Life Safety Code drives material approvals as well as ratings, and an unapproved system will not pass inspection no matter how good its data sheet is.

Check approval status at specification stage, and check that the approval covers the exact configuration you are using — substrate, primer, topcoat, thickness, and the section factor range.

Where it meets fabrication

Fire protection decisions ripple back into the steel package:

• Surface preparation. Intumescent systems require a specified blast standard and primer. That has to be agreed before the steel is painted, not after.
• Connections and bolts. Protection must be continuous across connections; bolt heads and cleats are part of the protected element.
• Handling. Shop-applied intumescent needs lifting points, packing and transport planned to avoid damage — and a documented repair procedure when it happens anyway.
• Records. Thickness readings and locations form part of the handover pack. Agree the sampling frequency and recording format up front.

Corrosion and fire are one specification

Where a member needs both, the systems must be compatible as a stack: blast standard, primer, intumescent, topcoat. Specifying them separately from two suppliers is how incompatibility gets discovered on site. Our guide to corrosion protection and ISO 12944 coating systems covers the other half.

Al Saqr Al Ahmar fabricates structural steel for buildings, plants and industrial facilities across the UAE, coordinating surface preparation and coating requirements as part of the fabrication package. Send us your specification.