Warehouse floor space in New Zealand carries a real (and high) cost. For operations running selective pallet racking across a large footprint, that cost often masks a familiar inefficiency: aisle space allocated to give every pallet immediate access, even when most pallets remain in position for days or weeks at a time. The result is a facility that prioritises flexibility at the expense of density, even when the operation does not need that flexibility.
Double deep racking addresses this directly. It stores pallets two positions deep on each side of every aisle, reducing the total aisle count required for the same pallet volume. The result is a meaningful density gain without the operational complexity or capital cost of drive-in racking or automated shuttle systems. For operations managing high volumes of a limited number of stock keeping units (SKUs), it is often the most practical route to better space utilisation with a single equipment change.
What double deep racking is
Double deep racking is a pallet storage system that positions pallets two rows deep on each side of an aisle, requiring a specialised double deep reach truck to access rear pallet positions. Each bay holds two pallets front to back rather than one, effectively doubling the storage depth per aisle face without requiring additional floor area.
When two runs are placed back to back, which is the standard configuration in most double deep installations, pallets are stored four positions deep and accessed from a single aisle on each side. This back-to-back arrangement is where the system delivers its most significant density gains relative to the aisle space consumed.
Storepro’s double deep racking systems can increase storage capacity by up to 50 per cent compared to a selective pallet racking layout covering the same floor area, with a space utilisation split of approximately 55 per cent storage area to 45 per cent working area. At any given time, 50 per cent of pallets are immediately accessible from the aisle. This distinguishes double deep racking from drive-in systems, where only the outermost pallet in each lane is directly reachable.
How double deep racking works
Double deep racking uses standard selective racking frames and beams, configured so each bay stores pallets two deep rather than one. The outer pallet occupies the front beam position. The inner pallet is stored behind it, accessible only once the outer pallet has been retrieved. The racking structure itself is not fundamentally different from selective racking; the operational change lies in the depth of storage and the forklift required to service it.
Accessing the rear position requires a double deep reach truck, also called an extended reach or pantograph reach truck. This forklift uses an extending pantograph mechanism to place and retrieve rear pallets without the truck itself entering the aisle. The operator extends the forks, places the rear pallet, retracts the mechanism and then places the front pallet in the outer position. Retrieval follows the reverse sequence: the outer pallet is removed, the pantograph extends to retrieve the inner pallet, and the outer pallet is returned or dispatched.
The aisle width required for double deep racking is slightly greater than for standard reach truck racking, to accommodate the extended mast movement and pantograph operation at height. Storepro specifies the aisle dimensions for each installation during the design phase, based on the reach truck model and the racking configuration.
Retrofitting to existing selective racking
Double deep racking can be retrofitted to existing selective pallet racking installations in many cases, using the same uprights and frames already in place. This makes it a viable upgrade path for operations that want to improve storage density without a full system replacement, and without the disruption of a rip-and-replace project.
Two conditions apply before a retrofit is viable. The existing racking must be structurally compatible with the new load and depth configuration, and the warehouse floor must meet the flatness tolerances required for double deep reach truck operation. Storepro assesses both during a design consultation before any retrofit project begins.
Storage density: double deep versus selective racking
Double deep racking delivers up to 50 per cent more storage capacity than a comparable selective racking layout in the same floor area. This gain comes from reducing aisle count rather than adding height, which means the benefit is most pronounced in facilities where floor area is the primary cost constraint rather than clear height.
| Selective racking | Double deep racking | |
| Storage depth per bay | 1 pallet deep | 2 pallets deep (4 deep back-to-back) |
| Pallets immediately accessible | 100% | Approximately 50% |
| Stock rotation method | Last in, first out (LIFO) or first in, first out (FIFO) | LIFO (FIFO not practical in most configurations) |
| Forklift type required | Standard reach truck or counterbalance | Double deep reach truck (extended pantograph) |
| Typical space utilisation | Approximately 40% storage, 60% aisle | Approximately 55% storage, 45% aisle |
| Storage capacity gain | Baseline | Up to 50% more than selective racking |
| Suited to high SKU diversity | Yes | No — performs best with low to medium SKU count |
| Retrofit from existing selective racking | Not applicable | Yes, subject to load and floor assessment |
The density gain comes with a direct trade-off: rear pallets are not immediately accessible, and the operation requires a specific forklift type. For operations where both conditions are manageable — typically those running low to medium SKU counts with non-perishable stock — the additional storage capacity represents a strong return on a relatively modest capital investment.
Operational requirements
Before committing to double deep racking, warehouse operators need to confirm that four operational requirements are in place or achievable. The reach truck requirement carries the most weight: it is the condition that most often determines whether double deep racking is viable for a given operation.
1. Forklift fleet: The operation must own or lease a double deep reach truck. A standard reach truck cannot reliably access rear pallet positions, and a counterbalance forklift is not designed for the aisle widths and mast heights involved. This is the most significant operational prerequisite and the primary reason some operations choose to remain with selective racking rather than upgrade.
2. Driver training: Operators must be trained specifically for double deep reach truck operation. The pantograph mechanism requires precise positioning to place and retrieve rear pallets without contacting the racking frame or adjacent pallets. Most equipment suppliers include training as part of a reach truck lease or purchase agreement.
3. Floor flatness: Double deep reach trucks operate at greater extended heights than standard reach trucks. The warehouse floor must meet sufficient flatness tolerances to support stable and safe operation at those heights. Floor flatness is a common constraint in older facilities and should be assessed before a double deep racking project is committed.
4. Aisle width: Aisles must be wide enough to accommodate the extended mast movement and pantograph operation of the double deep reach truck. The specific width depends on the reach truck model. Storepro specifies the aisle dimensions for each installation as part of the design process.
Stock rotation and SKU management
Double deep racking operates on a last in, first out (LIFO) basis by default. The most recently stored pallet occupies the outer position and is the first to be retrieved. The pallet stored first sits at the rear and is accessed last. This rotation sequence is determined by the physical configuration of the system, not by inventory software settings.
Achieving first in, first out (FIFO) rotation with double deep racking requires retrieving the outer pallet, placing it in a temporary location, accessing the rear pallet, and then returning the outer pallet. This adds handling steps and significantly reduces the efficiency gains the system is designed to deliver. For the vast majority of operations, FIFO rotation and double deep racking are not a practical combination.
The ideal profile for double deep racking is high pallet volume concentrated across a small number of SKU lines, with non-perishable or shelf-stable products where date-based stock rotation is not a compliance or commercial requirement. Third-party logistics (3PL) operators managing bulk consumer goods, fast-moving consumer goods (FMCG) distributors running seasonal or promotional stock, and cold storage facilities holding frozen product by line are all well-suited profiles.
Operations with high SKU diversity, perishable products with strict date codes or a need for unrestricted access to any individual pallet at any time are better served by selective racking or a system specifically designed to support FIFO rotation.
When double deep racking makes sense and when it does not
The reach truck requirement is the most useful initial filter. Operations already running a reach truck fleet are well-positioned to adopt double deep racking with a relatively straightforward equipment upgrade. Those relying entirely on counterbalance forklifts would need to acquire or lease a reach truck, which changes the capital commitment calculation significantly.
| Good fit | Poor fit |
| High pallet volume concentrated across a low to medium number of SKU lines | High SKU diversity requiring frequent individual pallet access |
| Non-perishable or shelf-stable products where date-based rotation is not required | Perishable products with strict date codes requiring FIFO rotation |
| Operations that already run a reach truck fleet or plan to | Operations relying solely on counterbalance forklifts with no plan to acquire a reach truck |
| Space-constrained facilities where floor area is the primary cost constraint | Facilities with poor or uneven floor flatness that cannot support reach truck operation at height |
| Inventory practices compatible with LIFO rotation | Operations where any pallet must be accessible at any time without pre-retrieval of outer pallets |
| Moderate capital budget relative to shuttle or drive-in systems | Very small pallet volumes where the density ROI does not justify the equipment change |
Where the operational profile is a strong match, double deep racking typically delivers better value than drive-in racking at a lower capital cost, with better individual pallet accessibility. Where the profile is a poor match, the system creates operational friction that negates the density benefit. The purpose of a design consultation is to determine which side of that line a given operation falls on before any investment is committed.
Double deep racking versus drive-in and shuttle racking
Storage density and operational accessibility sit at opposite ends of the same scale. Double deep racking occupies the middle ground: more density than selective racking, more individual pallet accessibility than drive-in systems, and significantly lower capital cost than automated shuttle racking. Understanding where each system sits helps operations choose the right level of density for their actual operational requirements rather than the maximum density their floor space could theoretically accommodate.
| Selective racking | Double deep racking | Drive-in racking | Shuttle racking | |
| Storage depth | 1 pallet deep | 2 to 4 pallets deep | Up to 10 deep | Up to 20 or more deep (automated) |
| Pallet accessibility | 100% at all times | Approximately 50% at all times | Outermost pallet per lane only | High — automated retrieval |
| Stock rotation | LIFO or FIFO | LIFO | LIFO only | LIFO or FIFO (system-dependent) |
| Forklift required | Standard reach truck or counterbalance | Double deep reach truck | Standard counterbalance (no mast clearance required) | Standard reach truck or automated carrier |
| Relative capital cost | Low | Low to moderate | Moderate | High |
| Ideal SKU profile | High SKU count, mixed volumes | Low to medium SKU count, high volume | Very low SKU count, bulk volume | High volume, high throughput operations |
Drive-in racking achieves higher storage density than double deep racking but requires a standard counterbalance forklift that drives into the racking lane, sacrificing both individual pallet accessibility and FIFO capability entirely. Automated shuttle racking achieves the greatest density with high throughput and can support FIFO rotation, but carries a substantially higher capital and maintenance cost. Double deep racking sits between these systems as the practical choice for operations that need more density than selective racking provides but cannot justify the cost or operational constraints of drive-in or shuttle alternatives.
The right choice depends on SKU count, pallet volume, stock rotation requirements and available capital. Storepro’s warehouse design consultants assess all four factors and recommend the system that fits the specific operation, not the one with the highest density specification.
How Storepro designs and installs double deep racking
Warehouse operators evaluating double deep racking benefit from a design process that starts with the specific floor space, forklift fleet and inventory profile of their facility rather than a standard product configuration. Storepro’s design consultants assess the space utilisation split, load characteristics and reach truck compatibility before specifying a system, and identify whether retrofitting to existing selective racking is viable or whether a new installation is required.Storepro’s double deep racking is modular and scalable, and the system can be expanded as storage requirements grow. The end-to-end service covers consultation and bespoke design, supply, project management, installation, compliance facilitation under AS/NZS 4084, and ongoing inspection and maintenance. Storepro operates nationally from offices in Auckland, New Plymouth, Christchurch and Hamilton. Reach out to a racking specialist today.