Mezzanine Load Rating

A key question when you’re considering installing a mezzanine floor, will be “how much weight do I need it hold?” To answer this, you’ll need to know the mezzanine load rating.

fire rated mezzanine

How much weight can a mezzanine floor hold?

Clearly, the mezzanine load rating for office space will be different from the load rating for heavy industrial use.

We’ll always take into account your intended use of your mezzanine floor, and draw on our extensive experience and knowledge of building regulations to help you determine your mezzanine load rating requirements.

We take great care, right from the initial consultation and design stages, in determining the correct load capacity for your purposes – including any anticipated future use.

The ongoing safety and structural integrity of your mezzanine are obviously paramount, and we always adhere to the specifications set out in Building Regulations Part A, BS6399 Part 1 and the recommendations and guidance in BRE Digest 437.

Mezzanines are often used to increase the capacity of a working environment for either storage or office space. Various factors such as the size of the mezzanine, travel distances, usage and the number and type of people that will be using the space at any given time will dictate what level mezzanine fire regulations are needed.

You can determine whether your mezzanine floor needs to be fire rated through checking specific criteria.

Why is a mezzanine floor safe working load important?

It is vital to know and comply with the mezzanine floor safe working load for your installation. Bear in mind that a mezzanine floor will not have the same depth of foundations as your ground floor; its strength, capacity and mezzanine load rating is determined by a combination of its floor, supports and the materials they are made from. The depth of the floor, and foundations on which the mezzanine floor’s supports will stand, are also critical factors.

Naturally, you’ll want your installation to deliver the best value with the optimum mezzanine floor capacity for your business. At Oracle Storage, we will ask detailed questions to work out the maximum mezzanine load rating you will ever need, so we can calculate the mezzanine floor safe working load accordingly.

By ensuring our design comfortably accommodates your maximum mezzanine floor safe working load, we safeguard against the risk and consequences of overloading. We are always fully aware of not only protecting the safety of the people and assets on your mezzanine floor, but also of those below it.

fire rated ceiling construction

Factors to consider for mezzanine capacity

There are several factors to consider when deciding on the mezzanine capacity you will need; principally:

  • what you are using your mezzanine for
  • the floor area and height available
  • the equipment or stored items which the mezzanine will have to support

Once we’ve discussed these variables with you, we’ll be able to work out the mezzanine load rating requirements.

For example, if you’ll be using your mezzanine floor for storage, will the items be stacked, how high can you safely stack them and what will be the maximum combined weight of the items per square metre? Don’t forget to take the weight of any handling equipment into account.

If the mezzanine will house heavy machinery, whereabouts on the floor will it be located; will it be distributed uniformly or concentrated on certain pressure points? Will it be mobile or static? Might there be areas which need extra reinforcement?

Obviously, the mezzanine load rating requirements will be greater if it’s used for heavy storage or equipment, compared to an office or retail space. A more robust floor, greater column density, more substantial columns and possibly additional swage plates and bracing will be required.

We also encourage you to think ahead – you might start off with relatively low mezzanine design loads, then find a future change of use could demand greater mezzanine capacity and higher loads. It will be more cost effective to build in this extra mezzanine capacity from the outset, rather than reinforce the installation later. We’ll be happy to discuss the options with you.

Building regulations and mezzanine floor load capacity

Your mezzanine floor load capacity is subject to Building Regulations Part A – Structural Requirements, and to BS6399 Part 1 – Loadings for Buildings: Dead and Imposed Loads.

  • The minimum loading for light storage applications under BS6399 is 2.4kN/m2.
  • There are greater mezzanine load rating requirements for concentrated loads, e.g. for pallet trucks or heavy machinery.
  • BRE Digest 437 introduced more flexible imposed loading recommendations, in line with the revised Management Scheme, and we have adopted these recommendations.

We usually suggest mezzanine design loads that are higher than the minimum loading, so you benefit from greater mezzanine floor load capacity as your business evolves – without the need for a major rebuild.

ARRI Lighting Mezzanine

Mezzanine load calculation

We use our mezzanine load calculator to determine the optimum specification for your required mezzanine load rating, and to ensure your installation provides safety, longevity and cost-efficiency.

As well as establishing the specification for your mezzanine platform, support columns and access arrangements, we also have to ensure your building’s floor has sufficient strength to bear the weight of your mezzanine and its loads.

Although all the columns are likely to be spaced evenly beneath the mezzanine, it’s those inside the floor’s perimeter that generally take the most weight, as they support the greatest platform area. Consequently, these are the columns we consider when using our mezzanine load calculator.

The actual calculation per column is based on its horizontal and vertical span, the square footage it supports and the mezzanine’s uniform load rating. From this we can deduce the column’s loading on your building’s floor.

We will need to know the depth of the floor and what is beneath it, e.g. solid rock or the type of soil. We use geo-environmental drilling specialists to take coring and drilling samples, which are then analysed in a soils laboratory for their load bearing strength. By combining this information with the loading per column, we can tell you whether your warehouse floor has the required strength to support your mezzanine, if we need to provide larger or reinforced footers beneath the columns or modify the mezzanine design. After the samples have been taken, your warehouse floor is reinstated using the appropriate load bearing materials.

This is why our mezzanine load calculation is vital – it helps us recognise and deal with construction challenges at the design stage so we can eliminate potential problems; just another example of our thorough approach.

Mezzanine floor compliance

Mezzanine floor compliance does not end with our installation. If you are taking full advantage of your mezzanine floor load capacity, it’s likely you will be using your mezzanine intensively. To ensure its continued structural integrity and safe performance, we recommend you operate a safety compliance policy with regular inspections.

BRE Digest 437 provides details of a Management Scheme designed to ensure that mezzanine floors are used within their safe operating limits. The Scheme comprises:

  • A Management Document
  • Loading Notices which must be displayed and adhered to
  • Appointment of competent persons to undertake regular inspections, surveys and structural appraisals
  • Appointment of a separate Manager to take responsibility for the Scheme.

We will explain this scheme to you in detail, to help you make continued optimum use of your mezzanine load rating whilst complying with the relevant regulations, and operating safely.

bleckmann two tier warehouse mezzanine

Guide for loading

BS6399 Part 1 sets out the load ratings for mezzanine floor supports, which are summarised in the table below.

The British Standards indicate minimum loads, and subsequently BRE Digest 437 has suggested higher mezzanine floor safe working loads in some categories. We recommend that, wherever possible, you adopt a higher mezzanine load rating than the minimum requirements. This will give you more flexibility in how you use your mezzanine floor load capacity, particularly as your business grows.

Other factors to bear in mind are the mezzanine load rating requirements for shelving, partitions and areas where hand pallet trucks or powered pallet trucks are used. We will make sure we fully understand your mezzanine floor requirements, and use our floor load calculator to ensure your installation is correctly specified.

UsageLoadMinimum imposed load
Office, workroom without storage, canteen

Uniformly distributed1

Concentrated load2

Proprietary lightweight partition

2.5kN/m

2.7kN

0.5kN/m2

Kitchen/laboratory

Uniformly distributed

Concentrated load

3.0kN/m2

4.5kN

Shopping/retail area

Uniformly distributed

Concentrated load

4.0kN/m2

3.6kN

Light storage

Uniformly distributed3

Concentrated load

Shelving

3.5kN/m2

3.50kN

2.5kN/bay

Medium storage

Uniformly distributed3

Concentrated load

Shelving

Hand pallet truck

5.0kN/m2

5.0kN

4.0kN/bay

7.0kN

Heavy storage

Uniformly distributed3

Concentrated load

Shelving

Powered pallet truck

7.0kN/m2

6.0kN

5.0kN/bay

12.0 kN

Notes:
1 According to BS6399 Part 1 – 5.1.2, uniformly distributed loads are the uniformly distributed static loads per square metre of plan area, and provide for the effects of normal use.

2 According to BS6399 Part 1 – 5.1.3, concentrated loads should be applied to individual members and assumed to act on them, unless there is evidence that adequate interaction exists to ensure that the load can be shared or spread.

3 For each metre of storage height, but with a minimum of 6.5.

Get in touch with a member of our team using the form below to discuss your mezzanine floor requirements.

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