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Guide · Mezzanines and platforms

Steel mezzanines: loading, serviceability and fire questions to settle early

Dubai, UAESources checked 23 September 2026Technical review pending

Sources, edition and review status 4 source documents
Applies to
Dubai, UAE
Covers
Mezzanines and platforms · Existing structures · Loads · Serviceability · Fire and egress · Approvals
Based on
Dubai Building Code 2021 Edition and UAE Fire and Life Safety Code of Practice (September 2018)
Source check
Source check with an independent AI review of the findings (23 September 2026). Numbers, tables and exceptions were read from the source pages. No independent human engineering or legal review yet.
Status
Technical review pending. Later amendments not exhaustively audited.

How this library uses sources · Source notes for this guide

The question

What has to be established before a steel mezzanine can be designed, and which questions are structural and which are fire and egress?

Short answer

Three groups of questions. First, the loads for the mezzanine’s actual use, including point loads from racking or equipment.1 Second, serviceability: deflection and floor vibration, checked separately from strength.23 Third, classification, fire and egress: whether the level counts as a mezzanine at all,4 what the fire code requires of its construction and exits,5 and how it affects the host building.6 In practice the first two are structural calculation questions, and the third needs the fire code, the relevant authority and usually a fire consultant.

First, is it a mezzanine?

The Dubai Building Code defines a mezzanine floor as an intermediate level between the floor and ceiling of a storey, equal to or less than one-third of the floor it is contained in. A partial floor larger than that is a floor, not a mezzanine.4

The UAE Fire and Life Safety Code sets its own conditions in Table 1.9, item 45. The aggregate area of mezzanines in a room, other than in special-purpose industrial occupancies, is limited relative to the open area of that room; enclosed space is not counted when determining the room’s size; and the mezzanine’s own area is not included in the room area.5

Practical consideration

The two documents measure against different areas, the floor in one and the open room area in the other. Check the proposed layout against both before the structure is sized.

Adding a mezzanine to an existing building is a change to that building. Mezzanine floors are included in gross floor area under Table A.3.7 Table A.1 distinguishes renovation, modification, reconstruction, change of use and addition, and where an addition relies on the existing building for escape or vertical transport, the existing building is also assessed.6

Authority routes differ. For example, Trakhees Circular 2/2025 states that, apart from its listed decoration works, extensions and minor structural modifications to existing facilities after completion require a Modification NOC regardless of the area of the modification.8

Loads for the actual use

Part F sets minimum uniform live loads by reference to Chapter 4 of ASCE/SEI 7-16, and adds that concentrated live loads are evaluated for objects creating significant point loads, including machinery, vehicles and storage racks. The supporting structure is also designed for mechanical, electrical and plumbing equipment in its designated areas and along its access route.1

Superimposed dead loads for partitions, finishes and suspended services are determined by the engineer with supporting calculations, subject to stated minimum allowances. Loading plan drawings showing the load provision should be submitted for approval, and later changes are not made without new approval.9

Practical consideration

Storage racks are outside the Dubai Building Code’s scope as structures,10 so a platform carried by racking needs its governing rules established separately. For a mezzanine that carries racking, the rack base loads are a design input, and the loading plan is the practical record of what the floor was designed for.

Serviceability: deflection and vibration

Deflection limits are to maintain the functional requirements, using the most adverse realistic combination of serviceability loads.2 For steelwork, Part F refers to the limits in AISC 360 and AISC Design Guide 3.11

For vibration, Part F requires the natural frequency of steel floor systems for normal occupancy to be evaluated in accordance with AISC Design Guide 11 or SCI P354.3

SCI P354 explains why a frequency check alone is not enough. A minimum frequency limit reduces the likelihood of resonance, but it gives no indication of how the floor will actually respond in service. The guide recommends predicting the response to the expected excitation and comparing it with acceptability criteria.12

Practical consideration

Light, long-span steel mezzanines are the case where this matters most. A floor can pass its strength checks and still feel lively under foot traffic, trolleys or nearby equipment.

Section through a steel mezzanine inside a host room, with six numbered design questions 123456
  1. Uniform and point loads from the intended use
  2. Beam deflection under realistic service loads
  3. Floor vibration response, not frequency alone
  4. Columns, base plates and the existing slab or frame beneath
  5. Guardrail at the open edge
  6. Stair and route to an exit
Where the questions sit on a typical mezzanine. Diagram only, not to scale and with no design values.

Fire and egress questions

Table 1.9, item 45 of the fire code lists construction and protection requirements for mezzanines in a separate column from the separation requirements. They include a fire-resistance rating for mezzanine construction, the area condition above, and conditions on openness to an unobstructed exit and on the number of means of egress.5

Practical consideration

Reading only the separation columns can suggest there is no fire requirement. Confirm the rating and conditions that apply to the actual occupancy with the fire consultant and Civil Defence.

Where steel members need fire protection, the fire code lists test methods for the contribution of applied protection, including EN 13381-4 for passive and EN 13381-8 for reactive protection.13

Spiral stairs are generally not allowed in means of egress. The fire code’s listed exceptions include a storage-occupancy mezzanine used only for storage and not as office space.14

Part C of the Dubai Building Code requires at least one accessible route to connect each storey and mezzanine, with exemptions linked to its elevator provisions.15

Guardrail requirements in Part B cover when a guardrail is needed, its height, openings, climbable elements and loads under ASCE/SEI 7-16, with listed exceptions.16 Part E states that the fire code’s guardrail and balustrade section is superseded by that clause.17

Settle these before sizing steel

  • Plan area of the mezzanine and of the host floor and room
  • Intended use now and in future, with any racking, equipment or trolley loads
  • What the columns bear on, and whether that structure has been assessed
  • Stair type and exit arrangement
  • Fire strategy and who is responsible for it
  • Which authority the project falls under

A working list for a first enquiry. It does not replace a fire strategy or authority requirements.

Scope and limits

Practical consideration

The fire code pages cited are from the September 2018 edition; later amendments were not audited for this guide. Requirements depend on occupancy and jurisdiction. Finesse Infra Steel Constructions provides structural calculation reports for the steelwork; fire engineering, the fire strategy and authority approvals sit with the parties appointed for them.

Questions this guide answers

Source notes

Numbered notes point to the exact section and physical PDF page. Page numbers are the PDF viewer’s page, which can differ from the number printed on the page. Sources checked 23 September 2026. These notes support the statements; they are not a substitute for reading the current document for a project.

  1. Dubai Building Code, 2021 Edition. Government of Dubai; official copy hosted by Dubai Development Authority. Part F, F.7.5 Live loads (printed page F34), PDF page 360. Open the publisher PDF at page 360 (opens in a new tab) ↩ ↩

  2. Dubai Building Code, 2021 Edition. Government of Dubai; official copy hosted by Dubai Development Authority. Part F, F.8.3.1 Deflection control, general (printed page F44), PDF page 370. Open the publisher PDF at page 370 (opens in a new tab) ↩ ↩

  3. Dubai Building Code, 2021 Edition. Government of Dubai; official copy hosted by Dubai Development Authority. Part F, F.8.8.1 Vibration, steelwork (printed page F47), PDF page 373. Open the publisher PDF at page 373 (opens in a new tab) ↩ ↩

  4. Dubai Building Code, 2021 Edition. Government of Dubai; official copy hosted by Dubai Development Authority. Part B definitions, Mezzanine floor (printed page B8), PDF page 28. Open the publisher PDF at page 28 (opens in a new tab) ↩ ↩

  5. UAE Fire and Life Safety Code of Practice, September 2018 (the edition offered on the publisher page when checked). UAE Ministry of Interior, General Command of Civil Defence; distributed by Dubai Civil Defence. Chapter 1, Table 1.9, item 45 Mezzanine, conditions i to vi, PDF page 96. Open the publisher PDF at page 96 (opens in a new tab) ↩ ↩ ↩

  6. Dubai Building Code, 2021 Edition. Government of Dubai; official copy hosted by Dubai Development Authority. Part A, A.5.1 and Table A.1 Existing building and application of the DBC (printed page A9), PDF page 11. Open the publisher PDF at page 11 (opens in a new tab) ↩ ↩

  7. Dubai Building Code, 2021 Edition. Government of Dubai; official copy hosted by Dubai Development Authority. Part A, Table A.3 spaces included in GFA (printed page A11), PDF page 13. Open the publisher PDF at page 13 (opens in a new tab) ↩

  8. Circular No. (2) of 2025 regarding minor modification and decoration works after completion certificate, 15 January 2025. Ports, Customs and Free Zone Corporation (PCFC), Trakhees. Paragraph following the decoration-works conditions, and the supersession paragraph, PDF page 2. Open the publisher PDF at page 2 (opens in a new tab) ↩

  9. Dubai Building Code, 2021 Edition. Government of Dubai; official copy hosted by Dubai Development Authority. Part F, F.7.4 Superimposed dead loads (printed page F33), PDF page 359. Open the publisher PDF at page 359 (opens in a new tab) ↩

  10. Dubai Building Code, 2021 Edition. Government of Dubai; official copy hosted by Dubai Development Authority. Part A, A.5.1 Scope, continuation (printed page A10), PDF page 12. Open the publisher PDF at page 12 (opens in a new tab) ↩

  11. Dubai Building Code, 2021 Edition. Government of Dubai; official copy hosted by Dubai Development Authority. Part F, F.8.3.3 Steelwork deflection limits (printed page F45), PDF page 371. Open the publisher PDF at page 371 (opens in a new tab) ↩

  12. Design of Floors for Vibration: A New Approach (SCI P354), Revised edition, February 2009. Steel Construction Institute. Section 1.2 Traditional approaches to design and 1.3 Scope (printed page 2), PDF page 14. Open the publisher PDF at page 14 (opens in a new tab) ↩

  13. UAE Fire and Life Safety Code of Practice, September 2018 (the edition offered on the publisher page when checked). UAE Ministry of Interior, General Command of Civil Defence; distributed by Dubai Civil Defence. Chapter 1, 7.1.39 Structural steelwork test standards, items xii and xiii, PDF page 198. Open the publisher PDF at page 198 (opens in a new tab) ↩

  14. UAE Fire and Life Safety Code of Practice, September 2018 (the edition offered on the publisher page when checked). UAE Ministry of Interior, General Command of Civil Defence; distributed by Dubai Civil Defence. Chapter 3, Table 3.4, item 16 Spiral stair, PDF page 267. Open the publisher PDF at page 267 (opens in a new tab) ↩

  15. Dubai Building Code, 2021 Edition. Government of Dubai; official copy hosted by Dubai Development Authority. Part C, C.5.1 General principles, item d (printed page C8), PDF page 158. Open the publisher PDF at page 158 (opens in a new tab) ↩

  16. Dubai Building Code, 2021 Edition. Government of Dubai; official copy hosted by Dubai Development Authority. Part B, B.4.2.5.2 Guardrails for fall protection (printed page B29), PDF page 49. Open the publisher PDF at page 49 (opens in a new tab) ↩

  17. Dubai Building Code, 2021 Edition. Government of Dubai; official copy hosted by Dubai Development Authority. Part E, E.10.1 Fire safety, general (printed page E26), PDF page 321. Open the publisher PDF at page 321 (opens in a new tab) ↩