In a warehouse or storage area, the installation of racks must follow precise rules to ensure safety, smooth movement of handling equipment and compliance with standards.
One of the most frequently asked questions concerns the distance between two racks.
This distance, known as the “circulation aisle” or “work aisle”, varies according to a number of parameters: type of rack, type of truck used, storage height and safety requirements. This article explains how to determine the right spacing and the mistakes to avoid.
1. Why is the distance between two racks so important?
Insufficient space between two racks can lead to :
- collisions with forklift trucks,
- difficulties accessing pallets,
- risks of falling when handling at height,
- a slowdown in logistics operations,
- non-compliance with safety regulations.
Well-calculated spacing optimises both safety and productivity.
2. The different types of aisle in a warehouse
There are generally three types of driveway:
1. Working aisles
These are the aisles where the forklift trucks travel to load and unload the pallets onto the racks.
2. Traffic lanes
They allow general circulation in the warehouse.
3. Safety aisles
They provide rapid access in the event of an incident.
Each has its own specific requirements.
3. What does the distance between two racks depend on?
The distance is not fixed: it depends on a number of criteria.
1. The type of trolley used
This is the most important factor.
- Manual pallet truck → narrowest possible aisle
- Stacker → requires more space
- Front-end forklift → wide aisle required
- Three-sided carriage (VNA) → very narrow aisle possible thanks to guide system
Each machine has a turning radius which determines the minimum width of the aisle.
2. Pallet size
A European pallet (1200 × 800 mm) does not require the same clearance as a 1200 × 1000 mm pallet.
3. Rack height
The higher it is, the safer manoeuvres need to be, so sufficient space is required.
4. The type of logistics flow
- fast flow → wider aisles
- long-term storage → possibility of narrower aisles
4. Recommended minimum distances
Here are the most common aisle widths used as references in warehouses.
Front-end forklift truck
Recommended aisle :
➡️ 3.00 m to 4.00 m
To allow full rotation of the carriage when picking up pallets.
Electric stacker
Recommended aisle :
➡️ 2.30 m to 2.80 m
Depends heavily on the length of the tiller.
Hand pallet truck
Possible aisle :
➡️ 1.80 m to 2.20 m
For small installations or light shelving.
Trilateral carriage (VNA – Very Narrow Aisle)
Very narrow aisle :
➡️ 1.60 m to 1.80 m
Only possible if the truck is guided (rails, wire guidance, etc.)
5. Minimum clearance between racks and walls
Apart from the working aisles, certain clearances are compulsory:
Between a rack and a wall
➡️ Minimum 10 cm, ideally 20 cm
To ensure aeration, inspection and avoid shocks.
Between two racks placed back to back
➡️ Variable spacing for different pallets
Most of the time, spacers are installed to ensure a uniform distance (20 to 30 cm).
6. Safety rules to be observed
To remain compliant and secure your warehouse:
- Aisles must be kept clear at all times.
- Distances must be marked on the ground (paint, PVC strips).
- Work areas must be properly lit.
- Alleys close to high-traffic areas must be equipped with protection (barriers, stoppers, bollards).
- Operators must be trained in space constraints and manoeuvring at height.
7. Mistakes to avoid
❌ Reducing aisles to “save space”.
❌ Mixing several types of trolley without adapting distances
❌ Ignoring floor conditions (irregularities = increased risks)
❌ Not taking into account the actual size of pallets
❌ Installing racks without prior floor markings
These errors compromise safety and increase the risk of accidents.
Conclusion
The distance between two racks depends mainly on the type of forklift, the height of the rack and the type of goods stored.
As a general rule :
- 1.80 to 4.00 m for aisles, depending on the trolley used
- 10 to 20 cm against a wall
- 20 to 30 cm between back-to-back racks
Getting the dimensions of your aisles right guarantees an efficient, fluid and safe warehouse.