Space Rescue are mezzanine floor builders who can design, fabricate, supply, and install a raised storage level for you to expand your warehouse floor area. Alternatively, we can simply deliver a mezzanine floor kit along with a plan. Our mezzanine floor is available for sale in Sydney, Melbourne, Brisbane, Adelaide, and Perth, with both delivery and installation options available in most parts of Australia.

Here is a picture of a structural mezzanine floor with a staircase and guardrail.

1. What is a Mezzanine Floor?

A mezzanine floor, by definition, refers to an intermediate floor in between two consecutive storeys. In the context of either a warehouse, factory, or shed, the two other levels are the ground floor slab level and the roof.

2. Mezzanine Floor Plan

To help you understand the terminology, below is a steel mezzanine floor plan and elevation drawing with labels showing the main components. These consist of main beams, columns, joists, flooring, and guardrail.

Here are two drawings of a mezzanine floor design example labelled with columns, beams, joists, guardrails, and a staircase: one showing a plan view and the other an elevation.

3. Benefits

(i) A simple solution to your space needs

Industrial mezzanines are a simple yet highly effective means of increasing the floor area within the confines of an existing warehouse by simply adding an additional level.

(ii) Less expensive than moving

Space Rescue are industrial mezzanine floor builders with the ability to design cost-effective solutions of any floor size and shape to save you the expense in time and money of having to move to larger premises.

4. Design Configurations

Below are six of the most common mezzanine floor design configurations. Let’s go through them one by one.

Type A is a left-hand corner; Type B is a right-hand corner; Type C is 3-side closed; Type D is 3-side open; Type E is floating; and Type F is a right-angle design configuration.

Here are six different plan-view sketches of common mezzanine floor design configurations.

5. Applications

a) Storage

In most instances, an industrial steel warehouse mezzanine structure is used to provide additional mezzanine storage for pallets. When pallets are involved, the use of a safety pallet gate and pallet jack would be required. As the pallet jack can exert high point loads, it is important to consider this when selecting the flooring material.

A mezzanine platform is simply another term widely used to describe a warehouse mezzanine used for mezzanine storage. They are generally found in a warehouse or industrial setting. Similarly, a raised storage area (also known by the acronym RSA) or raised storage platform are two other terms used to describe the same.

What shelving types are used on top of the floor?

We recommend the use of long-span shelving or steel shelving on top of the floor. Similar to a pallet jack, it is important to note that shelving can also exert high point loads on the floor surface.

b) Additional Office Space

It is common practice to increase the working area in a factory unit or warehouse by building a mezzanine office either above or below the deck. This enclosed space can be used for either additional offices, manufacturing, working, or assembly areas.

This can all be achieved with the use of partitions. Designs typically consist of stud walls and a combination of windows and doors.

In this scenario, the partitions would provide fall protection on top of the floor, eliminating the need for a guardrail or handrail system.

6. Components

a) Columns

Columns (also known as posts) support the steel deck. Posts are almost always square hollow steel sections and are typically around 100mm x 100mm in size. At the upper end of the post are the main beams. The main beams sit directly on top of the posts. A bolted connection secures the post to the beam.

b) Baseplates

The welding of a baseplate at the bottom of a post is common. It consists of a thick square steel flat plate that is typically 300mm by 300mm in size. A baseplate helps spread the load over the concrete slab. Anchors fix the baseplate to the slab.

c) Floor anchors

Floor anchors fix the posts to the slab. They anchor into your concrete slab (or concrete footing) with floor anchors via a baseplate welded at the bottom of the post.

d) Beams

The main beams are the horizontal structural steel members, typically structural I-beams (also known as RSJ’s), that sit on top of the columns. These beams are an essential component, providing support for the floor joists (and boards in some designs). In some instances, pre-cast concrete walls support the floor. These locations do not require posts.

e) Joists

Joists are also horizontal steel members and an essential element in a mezzanine kit. They support the flooring material. Main beams and/or side wall brackets support the joists. We use cold-rolled C-shaped purlins for our joists, made specifically by passing flat galvanised coil steel through a rollformer to form these long sections. They sit either directly on top of or within the depth of the main beams. Joists sit adjacent to one another with regular spacing. This spacing is typically 400mm from centre to centre. Their orientation is almost always perpendicular to the main beams.

f) Flooring Boards

Flooring boards generally sit immediately on top of the joists. Self-tapping screws (also known as self-drilling screws) affix the flooring sheets to the joists. Several different types of floor surfaces are available, depending on your application. These include tongue-and-groove floor boards (commonly industrial particleboard or structural plywood) and an open-style steel grate.

The tongue-and-groove board design provides greater strength around the areas where two boards butt up against one another. A PVC tongue joins the two adjacent boards through opposing board edge grooves to stop differential vertical movement. This keeps the floor nice and flat, particularly as dynamic loads are moved across its surface.

g) Balustrades

A balustrade is simply a low-height barrier that specifically stands between 900 and 1100mm high. It is used on the side of staircases, stairwells, walkways, catwalks, and exposed floor edges to stop people from falling from heights above one metre.

There are two situations that need to be considered.

Firstly, if the public will be using your floor, you must adhere to more stringent design requirements. For public use, the balustrade cannot have any openings greater than 125 mm. This requirement is to help prevent people, and in particular small children, from falling through them.

Furthermore, if the floor is higher than 4 metres, the balustrade must also not have any climbable elements, such as horizontal rails, located between 150 millimetres and 760 millimetres from the floor.

The second situation is where the floor’s use is restricted only to those working within the organisation. This case permits the use of a simple guardrail design. Please refer to the guardrail section below for more details.

h) Guardrail


The guardrail system is a simple and very common balustrade arrangement, designed to provide safety for personnel on and under a mezzanine floor level. It specifically consists of a top tubular steel handrail, a tubular steel midrail (a.k.a., knee rail or intermediate rail), and a kickplate (a.k.a., toe plate or toeboard). You must install all three elements parallel to the walkway or floor. Steel tubular stanchions support these elements, featuring hollow balls at the handrail and midrail heights. The hollow balls allow the tubular rails to pass through the stanchions. Installers bolt the stanchions to the deck and then weld the rails to the stanchion balls.


Identical to the balustrade’s overall height requirement, the top of the handrail must also be between 900mm and 1100mm. Steel tubular rails are generally supplied with a galvanised finish. They are specifically required to be between 30mm and 65mm in external diameter. When installed, the distance between the underside of the knee rail and the top of the flooring board is to be no greater than 560mm. Similarly, the gap between the bottom of the handrail tube and the top of the midrail tube is to be no more than 450mm.

Kick-plates are used at the floor edge within the guardrail system to help prevent objects from falling on personnel accessing the area below. The top of the kickplate needs to be a minimum of 100mm above the floor. When fitted, any gaps between the bottom of the kickplate and the floor must be less than 10mm.

i) Staircases

Staircase design may consist of straight sections, landings, and returns. The positioning of a staircase is often based on the platform size, shape, warehouse layout, and operational constraints.

7. Elements and Sizes

a) Sub-structure options

The substructure is typically assembled from structural steel components (both columns and main beams) as described in type (i) below or pallet racking (end frames and beams) as described in type (ii) below.

i) Structural steel

A structural steel sub-structure supports the deck of a structural mezzanine floor. It has the advantage of typically being able to offer greater clear spans under your floor and, hence, greater flexibility with the placement of support columns. This creates an opportunity for larger, clearer areas, or more free and open space, to accommodate specific work areas, machinery, and stock movement.

ii) Pallet Racking

A pallet rack or rack-supported floor is often made out of pallet racking components that support the deck, such as frames and beams. Pallet storage and shelving under the deck are common features of this structure.

Extending these frames above the floor level has its advantages. For example, it provides a ready-made means for including shelving above the floor.

Using pallet racking has disadvantages, including restricting the layout beneath your raised storage area. Conversely, a structural mezzanine floor requires fewer posts. Pallet racking and shelving can still be used under a structurally raised storage area without being part of the structure. This allows for the movement of racking and shelving at any time to accommodate changing needs.

The use of long-span shelving as another sub-structure material is also common. Less common is steel shelving.

b) Deck

The deck surface will consist of either tongue-and-groove flooring boards or mesh decks. Floor boards often lay on top of joists. The main beams support the joists within the sub-structure. Deck height, or the top of the finished floor, is generally between 2.4m and 4.5m.

8. Design Considerations

a) Types of Mezzanines

i) Free-standing

As the name suggests, this style of mezzanine structure relies only on the columns for support. It can stand freely without any other supporting aid.

ii) Wall-supported

There is often the option in modern warehouses to use adjacent concrete slab walls (also known as tilt slabs) to support your floor. As a result, this saves money and removes the need for some columns, thus improving the open area under your floor. A bracket, bolted to the wall, supports the floor.

b) Three types of deck design

i) Standard Deck Design

To explain, a typical deck design consists of the joists laying directly on top of the main beams. Contractors typically bolt joists, commonly consisting of C-shaped purlins, to cleats welded on top of the supporting beam. This is the definition of a top-mount design. This deeper-profile deck design is used when there is plenty of roof clearance.

ii) Low-profile deck design

In some instances, particularly when warehouse roof heights are low, we can reduce the deck profile height by positioning the joists within the profile height of the beam. Here, the joists are bolted to the beam via welded cleats. This design positions the top of the joists so that they are at the same height as the top of the beam. Concealing the height of the joist within the often deeper height of the beam considerably reduces the deck profile height. This design technique is often the difference in making the addition of a mezzanine area viable.

iii) Combination

In some situations, it is not possible to place the main beam directly adjacent to the wall, for example. To overcome this, we cantilever joists out from a beam set back from the wall. This permits the use of a cantilever arrangement with a top-mount design. If it is not practicable to run joists from the beam to the wall and use the wall to support the joists, this top mount design is used with this restriction.

Another situation is where it is necessary to cantilever the joists up close to a busy wall. In this scenario, the main beams adjacent to the busy wall side use a top-mount design, and the joists are stopped before the wall so as not to interfere with any data, water, or power fixtures.

c) Beam span and support

There are always a number of ways to support the main beams. This flexibility, along with a variety of beam sizes, provides the opportunity to accommodate the particular needs of our customers. For example, we have the ability to remove central support posts by using larger spans to create clearer areas under the floor. In addition to this, we are also able to remove beams and their posts adjacent to concrete tilt slab walls by using long wall angles to support purlins at their wall ends. Similarly, we are also able to remove posts under central beams that are adjacent to concrete tilt slab walls by using a wall support bracket.

9. Accessories

Below is a list of common accessories incorporated in to Mezzanine Floors.

a) Access Ladders

An alternative to a staircase is an access ladder. Some of the reasons you would choose an access ladder over a staircase are that they are cheaper and take up less space. Access ladders are not as safe and are a more awkward means of access. Furthermore, ladders are a secondary access option for a staircase.

b) Pallet Gates

Pallet gates consist of either sliding, swinging, or roll-over access. Interestingly, their selection is dependent on budget and operation. Their use makes it possible to transfer palletized loads or cages onto your platform.

c) Pallet Landing Skids

Steel plates protect the floor in the area where you deposit and retrieve pallets.

d) Columns and Post Protectors

As in pallet racks, column or post protection is available for protecting structural steel columns or uprights within pallet rack-supported floor levels.

e) Catwalks

A raised, horizontal walkway is the definition of a catwalk. A catwalk either connects two platforms together or joins an existing stair landing to a platform.

f) Pallet Jacks

For some raised storage areas, a pallet jack (aka pallet truck) will be needed and reside on top of the floor. Pallet jacks are used to place pallets in their proper position after they have been lifted up to the mezzanine level. Similarly, they are also used to retrieve pallets and place them near the pallet gate in readiness for a forklift or walk-behind forklift (a.k.a., walkie stacker) to collect them.

10. What is a raised storage area?

A raised storage area is a mezzanine floor. The storage of products, stock, and miscellaneous items is the most common use. Also known as a raised storage platform, this type of floor typically has a higher floor load rating, equal to or greater than 500kg per square meter. Conversely, a warehouse mezzanine floor typically serves to create extra working space for personnel. This usage has a lower floor load rating design requirement equal specifically to 300kg per square metre or more.

11. Do you supply mezzanine floor kits for sale?

Yes, Space Rescue can also supply mezzanine floor kits. Delivering materials in kit form is an option we provide on a case-by-case basis, as some of our customers are qualified builders and experienced in erecting this type of structure. We are able to deliver kits to any city, town, or regional area.

Furthermore, we are also able to offer you installation.

12. Design Considerations

To help you, here is a list of mezzanine floor design considerations below.

a) Mezzanine size and shape

Note: We can build your mezzanine to almost any size or shape!

  • What length would you specifically like your proposed floor to have?
  • What shape would you like your floor to have? (right-angled, rectangular, U-shaped, or other?)
  • What depth (or width) would you like your floor to have?
  • Would you like to provide a rough sketch with approximate dimensions of the shape that you are thinking of?
  • Would you like to extend your existing mezzanine?

b) Support by column and wall brackets

Note: We can place columns and supports almost anywhere!

  • Is there a need for large open spans with limited obstructions under your floor?
  • Do you require a certain spacing between columns?
  • Would you like us to create a specific, clear area under your floor?
  • In lieu of some columns, we may be able to create a more clear, unobstructed area for you by supporting the floor using brackets affixed to your concrete tilt slab walls. Would this be of interest?

c) Floor heights

Note: We can build either a single steel mezzanine level or one with multiple stories!

  • Top of floor height?
  • Clear underneath height?

d) Access

Note: This consideration relates to provisions for people and products to gain access while complying with the building codes for egress.

  • Where would you like your staircase?
  • Would you like a manual or automated pallet gate for loading materials onto your mezzanine level?
  • Is there a need for a conveyor to bring stock down from your raised storage area?
  • Is there a need for a stair ladder?
  • Do you think there may be a need for several staircases?
  • Are you planning on utilising an existing staircase or upstairs office for access?

e) Load Rating

Note: You may request a floor load rating to suit almost any floor loading application.

  • Will you use your warehouse mezzanine for either storage or additional working space?
  • Will there be high point-loads on top of your industrial mezzanine level?
  • Will you be using a pallet jack on top of your raised storage area?

f) Fall Protection

Note: We can build different styles of balustrades depending on usage!

  • Which sides of your floor will not be adjacent to either your building walls or your existing mezzanine level?
  • Are you planning on building an office with partitions both on top of and under your mezzanine floor?
  • Will your floor also be open to the public?

13. FAQ

How much does a warehouse mezzanine cost?

To explain, the cost of a warehouse mezzanine floor level varies dramatically depending upon the size, shape, floor height, floor capacity, number of staircases, access ladders and pallet gates required, post, frame, or wall support, sub-floor design, decking material, and type of deck profile. Generally, prices range from $300 + GST to $500 + GST per square metre, depending upon the floor size and complexity.

Are mezzanines expensive?

The cost of building a mezzanine floor kit is a relatively inexpensive exercise. To create a new space or to change the use and function of an existing space within the confines of your warehouse, shed, building, or factory, it is a brilliant option. Many find it an attractive option compared to the expense of relocating or acquiring additional business premises.

Does a factory mezzanine need planning permission?

Planning permission requirements vary depending on the location. We recommend checking with your local council and authorities to help you understand what these local requirements are.

14. Popularity and Availability

Industrial mezzanine floors have undoubtedly become increasingly popular with the never-ending rise in the cost per square metre of usable warehouse shed floor space and the expense of relocating.

Moreover, Space Rescue has been designing, supplying, and building affordable structural steel mezzanines for over 14 years in Australia.

15. Other solutions

Our cantilever racking, storage compactors, longspan shelving, dunnage racks, and pallet rack workbenches may also be of interest.