Adding a mezzanine is one of the most effective ways to create more usable space without moving premises.
However, a "mezzanine" covers several quite different structures and the right one for your site depends on a few factors. Namely, what you plan to store or do up there, how much height you have and how often your operation is likely to change.
Logical Storage Solutions installs mezzanine floors in warehouses across the UK, so we thought a guide on the different types would help you make an informed decision for your facility.
This guide walks through the main types of warehouse mezzanine system, how each one is built, where it works best and the questions to ask before you commit to one.
The Main Types of Warehouse Mezzanine System
Most warehouse mezzanine systems fall into one of four categories. The difference between them comes down to what holds the upper level up and what that level is designed to do.
Structural (Freestanding) Mezzanine Floors
A structural mezzanine floor is a standalone steel platform supported by its own columns and beams, independent of any racking or shelving below. It is the most versatile option because the space underneath stays open and the deck can be designed around almost any use, from bulk storage to picking, packing, production or offices.
Since it does not rely on the storage equipment for support, a structural mezzanine can carry heavier imposed loads and can span wider areas with fewer columns. It is also demountable, so it can be extended, reconfigured or moved if your operation changes.
Best for: mixed-use space, heavier storage on the upper level, pick and pack areas and offices or welfare facilities above the working floor.
Rack-Supported Mezzanines
A rack-supported mezzanine uses the uprights of the racking itself to carry walkways or a full deck above. The storage and the floor become one integrated structure, which is why these systems are often referred to as mezzanine racking or a pallet racking mezzanine.
This approach makes the most of tall buildings where you want to pick by hand at several levels rather than relying on a forklift for every location. Pickers work along the raised walkways while pallets or cartons are loaded into the racking from below or from the front.
Best for: high-density storage with manual picking at height, typically in e-commerce, parts and spares or distribution operations with a large number of SKUs.
Shelving-Supported Mezzanines
Shelving-supported mezzanines work on the same principle as rack-supported systems but use lighter-duty shelving, such as longspan or steel shelving, to carry the walkways. Each level is accessed by staircase and the result is a compact, multi-level store for small parts and cartons.
They are generally quicker and less costly to install than a structural mezzanine, but they are designed for lighter loads and the layout is fixed by the shelving grid, so they offer less flexibility if your needs change.
Best for: small parts, spares, archive storage and hand-picked stock that does not need pallet handling.
Multi-Tier Mezzanine Systems
Where eaves height allows, either structural or rack-supported mezzanines can be stacked into two, three or even more tiers. Multi-tier mezzanine systems turn tall, underused buildings into several working floors, usually linked by staircases, goods lifts or conveyors to keep stock moving between levels.
One Logical Storage Solutions project for an automotive parts distributor used a three-tier mezzanine with 5m x 6m column spans to add 3,600m² of storage, served by a multi-level goods lift, without the business needing to relocate.
Best for: high-bay buildings, fast-growing operations and sites where relocating is not practical.
Warehouse Mezzanine Systems Compared
If you are weighing up the options side by side, here is how the four systems compare at a glance:
- Structural mezzanines stand on their own steel columns and beams, carry the heaviest loads and offer the most flexibility, as the space below stays open and the structure can be extended or moved. They suit mixed use, heavy storage, offices and pick and pack areas.
- Rack-supported mezzanines use the pallet racking uprights to hold up the floor, offering high load capacity within the racking design. The layout is fixed by the racking, which makes them ideal for manual picking at height and operations with high SKU counts.
- Shelving-supported mezzanines rely on longspan or steel shelving and are designed for light to medium loads. Their layout is fixed by the shelving grid, so they work best for small parts, spares and archive storage.
- Multi-tier systems stack structural or rack-supported levels on top of each other, with load capacity varying by tier. They offer medium to high flexibility and are best suited to high-bay buildings and fast-growing operations.
How to Choose the Right Mezzanine System for Your Site
The best choice usually becomes clear once you have answers to a handful of practical questions.
What will the upper level be used for?
If the answer is anything other than storage, such as offices, packing benches or light production, a structural mezzanine is almost always the right starting point. If it is purely for hand-picked stock, a rack or shelving-supported system may give you more storage for your budget.
What are you storing and how heavy is it?
Palletised goods and heavy items point towards a structural or rack-supported design, while cartons and small parts can often be handled by a shelving-supported system. Your existing pallet racking layout also matters, as it may be possible to build a mezzanine into or around it rather than starting again.
How much clear height do you have?
Eaves height decides how many levels you can fit and whether a multi-tier system is realistic. Allow for headroom on every level, sprinkler or lighting clearances and the reach of any equipment working below.
Can your floor slab take the load?
Every mezzanine transfers its weight through columns or uprights into the slab. A survey will confirm whether the existing floor is suitable or whether spread plates or other remedial work are needed.
How likely is your operation to change?
If your stock profile, order volumes or processes shift regularly, the open, reconfigurable nature of a structural mezzanine is worth paying for. If your requirements are stable, an integrated rack or shelving-supported system can be the more efficient option.
How will people and goods move between levels?
Staircases, pallet gates, goods lifts and conveyors all affect the layout and the cost, so it is worth planning access early rather than adding it later.
For a closer look at how a mezzanine fits into day-to-day operations, our guide to using a warehouse mezzanine floor to improve efficiency covers workflow, picking and space planning in more detail. If you are still weighing up whether now is the right time, read when it is time to expand with a mezzanine floor, which also covers Building Regulations and typical costs.
How Logical Storage Solutions Can Help
With more than 14 years of experience in industrial storage, Logical Storage Solutions provides a turnkey service from initial survey through to installation, working with businesses across the UK, including some of the country's largest retailers and distributors.
- Bespoke mezzanine design: every mezzanine floor is engineered around your building, your workflow and how you expect to grow, rather than adapted from a standard layout.
- Complete installation: floors, staircases, edge protection and handrails are all handled by our team, with installs scheduled carefully to keep disruption to your operation to a minimum.
- Safety and compliance: projects are delivered in line with CDM 2015, with full risk assessments and method statements in place before work starts.
- Integrated racking: because we also design and install pallet racking for warehouses, rack-supported and multi-tier systems can be planned as a single scheme rather than two separate projects.
- Wider site improvements: if a mezzanine is part of a bigger reorganisation, our warehouse refurbishment service can bring layout, racking and new levels together under one plan.
- Ongoing peace of mind: once your system is in, regular pallet racking inspections help keep the racking that supports rack-supported mezzanines safe and compliant.
You can see examples of completed projects in our work.
Mezzanine Warehouse UK FAQs
What are the different types of mezzanine floor?
The four main types of mezzanine floor used in warehouses are structural (freestanding) mezzanines, rack-supported mezzanines, shelving-supported mezzanines and multi-tier systems. Structural mezzanines stand on their own steel columns and suit almost any use, including offices and heavy storage. Rack and shelving-supported systems use the storage equipment to hold up walkways, which makes them efficient for picking stock by hand at height. Multi-tier systems stack either type over several levels in buildings with enough eaves height.
What is mezzanine racking?
Mezzanine racking is another name for a rack-supported mezzanine, where the pallet racking uprights carry walkways or a full deck at one or more levels. Staff can then pick stock by hand from the raised levels while pallets are loaded from below. It is a popular choice for operations with a large number of product lines, as it adds both storage capacity and pick faces within the same footprint.
What is the difference between a rack-supported and a structural mezzanine?
A rack-supported mezzanine relies on the racking to hold up the floor, so the storage and the floor form one structure and the layout is fixed by the racking. A structural mezzanine has its own columns and beams, leaving the space underneath open and allowing the deck to be used for anything from storage to offices. Structural mezzanines are more flexible, while rack-supported systems are often the more space-efficient choice for dedicated picking areas.
Is multi-tier shelving the same as a mezzanine?
Multi-tier shelving is a form of shelving-supported mezzanine. The shelving uprights carry walkways at each level, accessed by staircases, creating a compact multi-level store. It is best suited to small parts, spares and cartons rather than palletised or heavy goods, which need a structural or rack-supported system.
Do warehouse mezzanine systems need Building Regulations approval?
In most cases, yes. A mezzanine used for storage, work or offices is usually treated as a new floor and needs Building Regulations approval, with fire safety, means of escape and structural loading among the key considerations. Requirements depend on the size and use of the mezzanine, so it is important to involve your installer early to keep the approval process on track.
Not Sure Which System Fits? Let Us Take a Look
Choosing between a structural, rack-supported, shelving-supported or multi-tier mezzanine is much easier with someone on site who can measure your clear height, check your floor slab and see how your team actually works. Logical Storage Solutions will assess your building, talk through what you need the extra level to do and recommend the system that gives you the most usable space for your budget, with no pressure to proceed.
Running a large logistics operation? Our article on how a mezzanine floor can transform your distribution centre looks at DC-specific layouts in more depth.
Request a quote or call our team on 0845 689 1300 to arrange a site survey.