Case study

How do you fire protect a mezzanine floor?

May 28, 2021 | Mezzanine Floors

Something our Design Technicians are regularly asked is ‘will my mezzanine floor need to be fire rated?’

Fire protection is a major component of UK Building Regulations which are in place to safeguard people, ensuring risk to their safety, health and welfare is minimal when in a building or within its vicinity. It’s been a legal requirement since February 1966 that construction projects apart from the class of work that is exempt must comply with UK Building Regulations. The practical guidance outlined in Part B of the UK Building Regulations approved document target five crucial fire safety and protection aspects:

  • Mechanism for early warning and evacuation means
  • Control of fire within the internal structures
  • Prevention of fire spread to concealed spaces
  • Containment of fire within the building
  • Emergency fire service access is quick and easy

mezzanine with underside, fascia and column fire rating


Mezzanine floor fire safety and protection

A mezzanine floor forms a structure within the building which could pose potential risk in the event of an emergency if fire safety regulations are not complied with.  Assessed on a case by case basis a mezzanine floor is only exempt from fire rating if:

  • The mezzanine length and width wise is less than 20m
  • The mezzanine is not used by the general public including staff members
  • The mezzanine is unoccupied apart from one or two people who require occasional access
  • The mezzanine covering less than half of the floor space bellow is used as storage only

What is mezzanine floor fire rating?

A fire rated mezzanine floor will give anyone on or around the mezzanine level up to one hour to vacate the building before the fire can take hold. There are various solutions that provide protection at different areas of the mezzanine:

Suspended ceiling panels – Fitted to the underside of the mezzanine floor, these panels prevent heat, fire and smoke from making its way to the level from bellow and the panels can hold their strength for up to one hour.

Edge fascia – In the case of fire making its way towards the mezzanines exposed edges, fascia fitted to the edges will shield the mezzanine from flames, smoke and heat for up to 60 minutes.

Column casing – Surrounding the columns, casings act as a barrier between the fire and column to ensure the components holding the mezzanine level in place remains unaffected for up to one hour.

The fire rated fixtures do not prevent or fight fire, but they do arm the mezzanine structure with a protective coat that will last long enough to evacuate the building whilst slowing down the effects of the fire before emergency services arrive.

Underside Fire rating

How much does mezzanine floor fire rating cost?

Fire rating can cost up to 25/30% of the overall cost of the mezzanine floor which although sounds substantial, the consequential cost of going against UK Building Regulations especially if a fire was to break out would be considerably higher. The initial cost of fire rating which is a legal requirement in most cases is far lower than the human, financial and reputation costs if UK Building Regulations were bypassed.

Mezzanine floor fire sprinkler system

A sprinkler system fitted to the underside of the mezzanine floor will provide early fire detection and release water to help put out flames however this is an optional extra and not a necessity. The initial investment of a sprinkler system involves the purchase of a large and quite expensive water tank which can be seen as an unnecessary cost given a sprinkler system is not a requirement, however some facilities that already have the tank and pipes in place opt to extend their sprinkler system to the mezzanine area.

Mezzanine floor smoke detection

However it’s used, a mezzanine measuring up to 20m in any which way should include a smoke detection system and alarm as stated in Approved Document B of UK Building Regulations.

Mezzanine floor fire rated column casings

A fire safe mezzanine floor design

As well as fire rating, smoke detection and sprinkler systems, design is crucial to fire protection and safety. Only a mezzanine floor solution with fire safety at the forefront of the design can be approved by a UK Building Regulating Officer.  At WSL our Design Technicians achieve this whilst meeting the needs of the business by drawing on the one hundred plus years of experience and knowledge accumulated between them. During the initial site survey, your space is assessed by the visiting designer who will measure the space, examine the possible obstructions and pay particular attention to the location of exit doors. This will enable a design tailored to the needs of the business whilst ensuring:

  • Staircases are located within close proximity of the exit door and positioned to provide a quick and easy exit
  • There are a sufficient number of staircases all close to an exit, particularly for large or multi tiered mezzanines.
  • Staircases are designed for ease of use without hazards by ensuring the step dimensions are sufficient with safe hand rail height.

WSL manufacture the bespoke mezzanine floor solution we design for each individual project and our manufacturing capabilities go beyond the mezzanine floor structure. We manufacture associated staircases, handrails and protectors so however your mezzanine floor staircase needs to be shaped and positioned the added flexibility of in house manufacturing means your mezzanine floor and staircases will match your desired look whilst meeting fire safety regulations. For extra safety and quality assurance WSL manufactures to the stringent requirements of UKCA of which we are certified as a Full SEMA Member.

Computerised plan drawing of mezzanine floor showing staircase locations, positions and shape

Assurance that your mezzanine floor complies with UK Building Regulations

WSL work with in partnership with UK Building Regulating Officers to whom we will send your mezzanine floor design for the purpose of ensuring all safety regulations are met through the design and fire safety is prioritised. Further to the initial design being signed off, a regulating officer will also visit the site on completion to assess the physical mezzanine to ensure it still meets the safety standards as illustrated in the initial design. Paperwork will be signed off by the officer confirming all building and fire regulations have been met and the documents will then be passed to you for safe keeping.


To discuss your safety assured, high quality mezzanine floor with fire safe design, why not call WSL on 0113 2045350 or email and we’ll arrange a free site survey at your convenience.

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