Warehouse Floor Joints: Should You Choose a Expansion Joint Cover or an Armoured Joint?

Concrete floors in warehouses and logistics centres need joints to control cracking and movement. But the type of joint protection you choose can make a real difference to how the floor performs over time, especially where forklifts and heavy vehicles pass.

Two common options are expansion joint covers and armoured joints. They look similar at first glance, but they are designed for different situations. Picking the wrong one can lead to edge damage, uneven surfaces, and higher maintenance costs.

This article explains the difference in simple terms and offers a practical way to choose.

 Figure: MSARJ – Classic Armoured Joint

Expansion joint covers or armoured joint — what is the difference?

A expansion joint cover sits on top of the joint. It bridges the gap, keeps debris out, and provides a smooth surface for people or vehicles to cross. It is usually installed after the concrete has cured. Cover plates are often used where the main concern is covering a gap and allowing some movement, rather than carrying heavy wheel loads across the joint.

An armoured joint is cast into the concrete during the pour. It has steel edges built in to protect the slab edges, along with load-transfer elements that help share wheel loads between adjacent slabs. Because it becomes part of the floor structure, it is generally better suited to areas with regular forklift traffic.

In short: a expansion joint cover goes over the joint, while an armoured joint becomes part of the floor.

How armoured joints protect the floor

Armoured joints address both edge protection and load transfer.

Steel edge protection
Hardened steel rails are set into the concrete edges at floor level. These rails take the direct impact from wheels and help keep the concrete edges intact.

Load transfer
Steel dowels or plates bridge the joint below the surface. They allow vertical loads to pass from one slab to the next, which helps keep the two sides level and reduces jolting as vehicles cross. Sleeves around the dowels still allow the slabs to expand and contract horizontally.

Figure: Load transfer mechanism of the MSARJ armoured joint.

Which joint does your floor need?

The right choice depends on how the floor will be used. Below is a general guide. Project conditions vary, so it is always worth checking with an engineer before finalising the choice.

A note on slab thickness
Armoured joints protect the joint edges and help transfer loads, but they do not make a thin slab suitable for heavy traffic on their own. For regular forklift use, slab thickness and sub-base design generally need to be reviewed together with the joint choice.

MEISHUO armoured joint range at a glance

• MSARJ – Classic Armoured Joint
  A versatile option for slab thicknesses from 100 mm to 300 mm and joint openings up to 20 mm. Available in black steel, galvanised steel, and stainless steel. Crossover styles are available for intersections and corners.

• MSARJA – Adjustable Armoured Joint
  Includes a height-adjustment feature, useful when slab thickness varies on site or final levels are not fully confirmed.

• MSARJBM – Heavy-Duty Armoured Joint
  Designed for demanding industrial and warehouse applications with heavy traffic.

• MSARJS – Sinusoidal Slide Armoured Joint
  Has a wave-shaped top profile that can give a smoother, quieter crossing. Often considered for AGVs or areas where ride quality matters.

• MSSCJ – Steel Sinusoidal Top Plate Joint
  Designed for wider joint openings, typically 15 mm to 40 mm. The two top plates slide over each other as the joint width changes.

 Figure: Schematic diagram of MSARJ armoured joint

Key points to consider

Building use
Think about how the space will be used now and in the future. If vehicle routes may change, a joint that allows smooth crossing in any direction — such as MSARJS or MSSCJ — may offer more flexibility.

Traffic
Consider the type of wheels, load, frequency, and speed. Straight joints can be fine where vehicles cross at an angle or do not pass directly over them. For frequent straight crossings, a sinusoidal or shaped joint can reduce impact.

Environment
For wet areas or outdoor slabs, galvanised or stainless steel finishes are generally more resistant to corrosion. In clean-room or chemical-handling areas, stainless steel is often preferred.

Safety and sealing
If the joint gap must be covered for safety or to prevent spills entering the ground, a cover plate system such as MSSCJ/MSBSL or a sealed joint detail may be more appropriate than an open armoured joint.

What height of armoured joint do I need?

The joint height is usually chosen to be slightly less than the slab depth — commonly around 10–20 mm less. This helps the top sit flush with the finished floor while leaving enough concrete below. The exact difference depends on the product series and site details, so it is best to confirm with the product data or your engineer.

For example, a 180 mm slab might typically use a 160 mm armoured joint, but the final choice should be checked against the specific product and floor build-up.

Frequently asked questions

Can I use a cover plate in a warehouse with forklift traffic?​
Yes, in some cases. Heavy-duty cover plates are available, but they are generally more suitable for lighter or occasional traffic. For busy forklift routes, an armoured joint is often the more durable choice.

Is an armoured joint the same as an expansion joint cover?​
No. Armoured joints are usually installed in contraction or control joints, where the slab is not fully separated and the movement is relatively small. Expansion joint covers are used where the slab is fully separated and larger movement is expected.

Will an armoured joint fix a thin slab that is not strong enough for forklifts?​
No. An armoured joint protects the edges and helps transfer loads, but the slab itself still needs to be thick enough and well supported for the expected traffic.

How do I choose between MSARJ, MSARJS, and MSSCJ?​
MSARJ is a good starting point for standard conditions with joint openings below 20 mm. MSARJS and MSSCJ are often considered where ride smoothness, wider joints, or multi-directional traffic matter. Your project engineer or MEISHUO team can help you decide.

Can armoured joints be used outdoors?​
Yes, with the right finish. Galvanised or stainless steel options are generally preferred for outdoor or wet environments.

Choosing the right floor joint system depends on slab thickness, traffic type, joint width, and site conditions. If you would like help selecting a model, contact the MEISHUO team. We can review your project details and provide a quotation.