Case study

Mezzanine floor weight load capacity – A detailed overview

Mar 1, 2023 | Mezzanine Floors

What will be the maximum load rating for my mezzanine floor? This is a very valid question and something our Design Technicians are routinely asked about. The truth is that there is no immediate direct answer, although a precise calculation can be provided once crucial information about your space, requirements and preferences have been gathered. As unexciting as it sounds, calculating the weight load capacity of a potential mezzanine floor installation is in fact one of the most important aspects of the design. This is because structural and occupant safety depends on these calculations being accurate.

When you see a mezzanine floor in a building, you are looking at a structure that has been specifically designed to meet the requirements of that particular operation. This could be a retail mezzanine floor which has been implemented to provide additional product display areas, or a warehouse mezzanine floor used to accommodate pallets or shelving systems. Production mezzanine floors are often required to safely hold the weight of heavy machinery or equipment whilst an office mezzanine would need to safely support numerous people carrying out their office based duties. So, when we consider such variations, it’s easy to see why weight load capacity does vary from mezzanine to mezzanine.

For a maximum weight load capacity to be determined, various factors must be taken into account during the design stage, but before we go all technical, let’s underline the reasons why the mezzanine floor solution is so remarkable!

Why the mezzanine floor is the favored solution

The mezzanine floor installation enables the expansion of productive space without there being any need for substantial construction work.  Rather than extend outward, the much needed new space is installed overhead, approximately midway between the existing ground floor and ceiling. Almost a floating floor, the mezzanine platform is a duplication of the footprint area below it, giving you double the practical space within the same surface area. This is a much more affordable and convenient way of acquiring more space when compared to the prospects of a building extension or relocating the business. Besides the necessity of sufficient height space, there is very little preventing the mezzanine floor option from becoming a reality. There is no discouraging list of business types or industries for which the mezzanine floor is not suitable and with the right weight load capacity, a mezzanine floor can safely support any business activity!

warehouse multi tier mezzanine floor

What is mezzanine floor weight load capacity?

The term “maximum weight load capacity” means the utmost weight that the structure can safely support. All mezzanine floor structures manufactured by WSL are made up of steel sections and to the stringent BS EN 1993-1-3 and UK National Annexes, however the quantity, thickness, spacing and size of the sections will vary in accordance to the required weight load and how the load is distributed across the platform:

  • Universally Distributed Load (UDL) –the load is spread equally across the mezzanine floor surface.
  • Point Load – the heavy load is restricted to one single area of the mezzanine floor surface.
  • Dead Loads – a constant weight from a stationary fixture. This includes the decking, columns and static equipment
  • Live loads – where loads are mobile. This can include people, equipment on wheels and furniture.

Where sections are too slight and outspread, a deflection of the floor is much more likely under a heavy load and this can very easily result in the floor falling through. This is why you’re WSL Design Technician is always keen to understand your operation and how you intend to use the space provided by the mezzanine platform.

Columns are the vertical section of the structure and serve as resting compression to the horizontal purlins that support the activities on the flat floor surface. The use of columns are unavoidable because without them, the floor couldn’t be elevated nor could it be safely supported, however the column grid can be designed to suit the activities on the floor below. Where a smaller grid might cause obstruction, the grid can be widened, creating more space between the columns which would then sit on a wider base plate to ensure stability and effective weight load support.

The material used to create the floor surface covering the steel sections can also vary in accordance to the weight of activates taking place on the platform.  Whilst “standard” 38mm T&G HD particle boards is more than adequate in many instances, oriented strand board (OSB), birch plywood, steel or even concrete can also be an option.

purlin sections in place

Why are weight load calculations so important?

Safety!! This is the most significant reason why our designers prioritise weigh load capacity as part of the design. No business owner would want to endure the anguish and consequences of a serious incident as a result of weight overload on the mezzanine platform.  As an employer or business owner the responsibility of ensuring occupant safety as they access the mezzanine floor structure or the area around it, rests with you. The Provision and Use of Work Equipment Regulations 1998 (PUWER) states that employees must not face unnecessary risk when using workplace equipment, and the use of a mezzanine floor comes under this category.

mezzanine floor columns

How will the weight load capacity calculated?

Calculating the correct weight load capacity means to appropriately quantify and configure the components. The final calculations are based on a combination of:

  • How you intended to use the mezzanine floor
  • How the weight will be distributed (universal/point loads)
  • Weight movement on the mezzanine (dead/live loads)
  • The size and height of the platform
  • Whether there is an anticipated change of use – this is because a light load capacity would be unsafe if it was to later take a heavier load.

But, rather than trying to get your head around weight load specifics and calculations, you can just leave this to your WSL mezzanine floor design expert, who will use the information gathered from yourself during the site survey to calculate the appropriate weight load capacity.

What is a mezzanine floor weight load notice?

Once you have established the weight load capacity of your mezzanine floor, it is important to communicate this to your workforce. Without access to this vital information, it could be quite easy to unknowingly overload the platform. Weight load notices, displayed conveniently allow for an immediate identification of the maximum weight load limit as and when needed. Providing quick guidance, weight load notices save time and effort when this specific information is required whilst acting as a firm reminder of weight load awareness.  SEMA (Storage Equipment Manufacturing Association) stipulate the importance of weight load notice as a key safety component for all types of workplace storage equipment and mezzanine platforms, and as a designer and manufacturer with full SEMA membership, WSL is entirely consistent with this. Weight load notices accompany all mezzanine floors designed, manufactured and implemented by WSL.

Office Mezzanine Floor Weight Load Notice

Mezzanine Floor Inspections

Although your mezzanine floor may have been designed and manufactured to support the weight of your business activities, it is important that you undertake appropriate measures to ensure high safety levels are continual.  A mezzanine floor that has become unsafe due to damage or wear and tear will put the safety of your staff, customers or visitors at risk and will no longer be compliant with PUWER.  An annual mezzanine floor inspection  carried out by a WSL safety inspector is the route to mezzanine floor safety assurance. These none disruptive inspections will detect any weaknesses that could potentially risk the safety of the structure. At WSL our qualified and experienced inspectors will examine every component, looking for potential risks including any compromise to weight load capacity. This could be a damaged floor surface due to wear and tear or a weakened column after an accidental collision for example. Any concerns or damage found along with advice on appropriate action will be documented in a full mezzanine floor inspection report which will be sent to you.

A weight lifted with WSL!

Trying to understand the ins and outs of mezzanine floor weight load capacity can be quite a task if this is something you’re not familiar with, so here’s the good news! Your WSL designer has considerable experience and knowledge when it comes to this very technical element of mezzanine floor design. In addition we are a designer and manufacturer of bespoke mezzanine floors with a Full SEMA Membership and UKCA accreditation, so you can be assured of the very highest quality and safety standards. Want to know more? Call our team today on 0113 2045350 or email

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