As e-commerce businesses in the USA continue to grow rapidly, so does the need for efficient warehouse storage systems. One of the best storage solutions for warehouses handling large, bulky, or irregularly shaped products is a cantilever racking system. Designing the right racking system can drastically improve space utilization, picking efficiency, and inventory organization in an e-commerce fulfillment warehouse.
This guide explains how to design a cantilever racking system for your e-commerce warehouse, including planning considerations, layout design, safety standards, and optimization tips.
Understanding Cantilever Racking Systems
A cantilever racking system is a type of warehouse storage rack designed with horizontal arms that extend from vertical columns. These arms support long or oversized loads like furniture, pipes, lumber, and heavy cartons—making it ideal for e-commerce operations that deal with mixed or irregular products.
Unlike traditional pallet racks, cantilever racks have no vertical obstructions on the front, allowing for easier loading and unloading of long items using forklifts or side loaders.
Key Components of a Cantilever Rack
Before designing, it’s important to understand the main components:
- Base: Provides stability and anchors the structure to the floor.
- Upright Columns: Vertical supports that carry the load-bearing arms.
- Arms: Horizontal beams that hold the stored material.
- Braces: Connect uprights together for additional stability.
- Decking (optional): Can be added to convert cantilever racks for smaller boxed items.
Each part must be selected based on weight capacity, load dimensions, and warehouse environment.
Step-by-Step: How to Design a Cantilever Racking System
Designing the ideal cantilever racking layout involves more than just assembling metal arms and columns. It’s about aligning storage design with your e-commerce fulfillment workflow, inventory size, and safety regulations.
Let’s walk through the process step-by-step.
1. Assess Your Inventory and Product Dimensions
Start by categorizing your inventory. E-commerce fulfillment centers usually store a mix of products: long boxes, furniture, metal rods, and oversized packages.
Measure:
- Maximum load length and height
- Average product weight per unit
- Handling equipment dimensions (forklifts, stackers, etc.)
This data determines the arm length, arm load capacity, and rack height needed.
For instance:
- Light-duty cantilever racks are ideal for e-commerce goods like tubing or boxed merchandise (under 1,000 lbs per arm).
- Heavy-duty racks are used for lumber, steel, or machinery parts (over 2,000 lbs per arm).
2. Determine the Racking Type: Single or Double-Sided
You can choose between:
- Single-sided racks: Mounted against a wall; best for warehouses with limited floor space.
- Double-sided racks: Accessible from both sides, providing higher storage density and faster picking efficiency.
In large fulfillment centers, double-sided cantilever racks are common because they optimize floor space and improve material flow.
3. Plan the Warehouse Layout
Efficient layout design directly impacts your warehouse throughput. Consider these factors:
- Aisle width: Ensure sufficient space for forklifts or order pickers.
- Product flow: Align racks with inbound/outbound processes to minimize travel time.
- Height restrictions: Check building clearance and sprinkler system requirements.
- Safety zones: Maintain OSHA-recommended clearances for operational safety.
Use a CAD layout or 3D warehouse design tool to visualize placement, ensuring every inch of space is used efficiently.
4. Calculate Load Capacity and Arm Spacing
Incorrect load distribution is one of the most common design mistakes.
Follow these steps:
- Total the weight per load level and per column.
- Divide load weight evenly across arms.
- Choose arms and uprights rated above your calculated weight for safety.
For example, if a product weighs 2,400 lbs and rests on 3 arms, each arm should support at least 800 lbs (ideally more for safety margin).
Arm spacing should match product length to prevent deflection or bending.
5. Choose Materials and Finishes
Cantilever racks come in steel or aluminum—steel being the most durable for heavy-duty applications.
Consider the warehouse environment:
- Powder-coated finish: For indoor dry storage.
- Galvanized steel: For humid or outdoor conditions.
- Custom colors: Help differentiate storage zones or product categories.
Durability and corrosion resistance are crucial for long-term performance and safety compliance.
6. Incorporate Safety and Compliance Standards
Safety is non-negotiable in warehouse design. Follow OSHA and RMI (Rack Manufacturers Institute) standards when installing racking systems.
Key safety tips:
- Use locking pins to secure arms.
- Install end stops to prevent product roll-off.
- Perform regular inspections for bent arms or damaged braces.
- Label load capacities visibly on each rack section.
Safety-compliant racks reduce accidents and increase operational efficiency—especially in fast-paced e-commerce warehouses.
7. Integrate with Warehouse Management System (WMS)
Your cantilever rack design should align with your WMS or inventory software.
Label each arm level or rack bay for barcode or RFID scanning, allowing real-time inventory tracking.
This digital integration helps:
- Reduce picking errors.
- Track SKU locations efficiently.
- Optimize space utilization over time.
8. Allow Room for Scalability
E-commerce demand is unpredictable. Design your cantilever system with future growth in mind.
Choose modular rack designs that allow easy expansion as inventory grows.
Add-on sections or adjustable arms can accommodate new product categories without requiring a complete overhaul.
Advantages of Cantilever Racking for E-Commerce Fulfilment
Designing your warehouse with a cantilever racking system offers several advantages:
- Maximized vertical space for bulky or long products.
- Faster picking and restocking, improving order fulfillment times.
- Flexible configurations to adapt to changing SKUs.
- Unobstructed front access, reducing handling damage.
- Durable steel construction for heavy loads.
This makes it a cost-effective storage solution for e-commerce retailers managing a mix of products—from long packaging materials to oversized items.
Common Design Mistakes to Avoid
When designing your cantilever racking system, avoid these pitfalls:
- Ignoring load distribution – Uneven spacing can lead to rack collapse.
- Overlooking forklift clearance – Insufficient aisles slow operations.
- Underestimating future storage needs – Always plan for expansion.
- Skipping professional engineering input – Load calculations should be verified by experts.
A well-designed racking layout not only saves costs but also enhances warehouse safety and productivity.
Maintenance Tips for Long-Term Performance
Regular maintenance ensures your racking system remains safe and efficient:
- Inspect uprights and arms for cracks, bends, or rust.
- Tighten all anchor bolts and connections periodically.
- Repaint or galvanize damaged surfaces.
- Keep aisles free from debris and product overhang.
Following a preventive maintenance schedule helps avoid costly downtime or accidents.
FAQs About Designing Cantilever Racking Systems
Q1. What type of products are best stored on cantilever racks?
Cantilever racks are perfect for long, bulky, or irregularly shaped products like lumber, pipes, carpet rolls, or large boxes commonly found in e-commerce fulfillment warehouses.
Q2. How do I determine the right arm length and spacing?
Measure the length of your longest load and divide it evenly across multiple arms. Spacing should prevent bending or deflection under load. Consult your racking manufacturer for capacity charts.
Q3. Can cantilever racks be used for palletized goods?
Yes, with decking attachments (like wire mesh or wood planks), cantilever racks can support palletized or boxed goods, making them versatile for mixed inventory warehouses.
Q4. Are cantilever racks adjustable?
Yes. Most systems allow for arm height adjustment, enabling you to adapt storage levels as inventory changes over time.
Q5. What safety standards should be followed?
Follow OSHA and RMI standards, including proper load labeling, anchoring, and periodic inspections to prevent rack failure or accidents.
Q6. How much weight can a cantilever rack hold?
It depends on the rack design. Light-duty systems may hold 500–1,000 lbs per arm, while heavy-duty industrial systems can handle up to 5,000 lbs per arm or more.
Q7. What’s the best layout for an e-commerce warehouse using cantilever racks?
A U-shaped or straight-line layout aligned with inbound and outbound areas minimizes travel distance and improves picking efficiency.
Q8. How do I plan for future warehouse expansion?
Opt for modular rack designs with bolt-on extensions or adjustable arms. This lets you scale up storage without major reconstruction.
Conclusion
Designing a cantilever racking system for an e-commerce fulfillment warehouse involves careful planning—from understanding your product dimensions to aligning with warehouse workflows and safety regulations.
A well-engineered design enhances storage density, picking speed, and operational safety, giving e-commerce businesses a competitive advantage in fast-paced distribution environments.
Whether you’re upgrading an existing warehouse or building a new facility, investing in the right cantilever rack design will support your business growth and scalability for years to come.