Pallet Rack Systems
Pallet Rack Systems span selective to cantilever. DACO says 100% selectivity and The most common bay size is 96 inches wide by 44 inches deep. MH-USA says accounts for roughly 85% of all pallet rack installations. Apex lists five to 10+ pallets deep per lane. Conesco lists Drive-In (2–4 Deep) and used Selective $20–$50 with 50–70% savings.
Last reviewed: September 4, 2026
Pallet rack systems
Selective Pallet Rack Systems
Selective racking provides direct access to every pallet position, making it the most common warehouse storage configuration. Available in roll-formed (lighter duty, lower cost) and structural (heavy duty, higher capacity) designs.
Key Characteristics
- Selectivity: Every pallet directly accessible
- Configuration: Uprights with adjustable beam levels at regular vertical intervals
- Aisle width: Varies by forklift type (counterbalance, reach truck, VNA)
- Best for: High SKU count, diverse products, frequent picking
Roll-Formed vs Structural
Roll-formed: Cold-formed steel profiles with teardrop or keyhole connections. Lower cost, suitable for most standard applications. Easier to reconfigure.
Structural: Hot-rolled I-beam construction with bolted connections. Higher load capacity, better for seismic zones, heavier products, or rack-supported buildings. More expensive and rigid configuration.
Double-Deep Pallet Rack Systems
Double-deep systems store two pallets deep per side of the aisle, reducing aisle count and increasing storage density versus selective. Requires double-reach forklifts with telescoping forks.
Key Characteristics
- Selectivity: Every other pallet — must access front pallet to reach rear pallet
- Density gain: Higher pallets per square foot versus selective
- Equipment: Double-reach forklift required
- Best for: Moderate SKU count, space-constrained facilities
Operational Considerations
Pair identical SKUs in front-back positions. Front pallet picked first exposes rear pallet. Works well for products with predictable depletion rates where both pallets picked within similar timeframes.
Drive-In and Drive-Through Systems
Drive-in systems use continuous rails allowing forklifts to drive into the rack structure. Pallets rest on rails rather than beams. Drive-in (single entry, LIFO) versus drive-through (entry both ends, FIFO).
Key Characteristics
- Storage depth: Multiple pallets deep per lane
- Density gain: Higher versus selective (eliminates aisles)
- Access pattern: LIFO (drive-in) or FIFO (drive-through)
- Best for: Low SKU count, high volume per SKU, cold storage
Design Requirements
- Rail strength: Must support full pallet weight with continuous sliding contact
- Entry guides: Protect uprights from forklift impact at lane entrance
- Top ties: Connect upright frames across lanes for lateral stability
- Forklift clearances: Maintain safe clearance between mast and uprights
Push-Back Rack Systems
Push-back systems use nested carts on inclined rails to store multiple pallets deep per lane. Loading a pallet pushes existing pallets back; unloading allows gravity return to pick face.
Key Characteristics
- Storage depth: Multiple-deep configurations available
- Access pattern: LIFO (last in, first out)
- Density gain: Higher versus selective
- Best for: Moderate SKU count, multiple pallets per product
Cart Mechanisms
Nested carts ride on inclined rails with each pallet positioned on a separate cart. Speed controllers prevent carts from accelerating too quickly on return. Regular maintenance required for wheels and rails.
Pallet Flow (Gravity Flow) Systems
Pallet flow uses roller conveyors on a slight decline. Pallets loaded at high end automatically flow by gravity to picking face at low end, ensuring first-in, first-out rotation.
Key Characteristics
- Storage depth: Multiple pallets deep per lane
- Access pattern: FIFO (first in, first out)
- Density: Very high cube utilization
- Best for: Perishables, pharmaceuticals, food products with expiration dates
Design Features
- Roller tracks: Full-width or skate-wheel configurations
- Decline: Gentle slope depending on pallet weight and roller type
- Speed controllers: Brake mechanisms prevent pallet damage at pick face
- Separators: Keep adjacent lanes independent for proper flow control
Maintenance Requirements
Rollers require regular inspection and lubrication. Speed controllers need periodic adjustment. Damaged pallets can jam lanes — immediate clearing essential to maintain throughput. Budget for annual maintenance contract.
Cantilever Rack Systems
Cantilever racks use arms extending from a central column, ideal for long or bulky materials that won't fit on standard pallet beams (lumber, pipe, steel bar stock, sheet goods).
Key Characteristics
- Configuration: Arms extend from upright column
- Adjustability: Arms reposition vertically for different material heights
- Capacity: Arms rated individually
- Best for: Lumber yards, steel service centers, pipe and tubing distributors
Single-Sided vs Double-Sided
Single-sided: Arms on one side only, typically against wall. Lower cost, suits narrow spaces.
Double-sided: Arms on both sides of central column. Higher capacity utilization, requires wider aisles, more common in open warehouses.
System Selection Criteria
By SKU Count and Volume
- High SKU count, low volume per SKU: Selective
- High SKU count, moderate volume: Double-deep
- Moderate SKU count, multiple pallets per product: Push-back
- Low SKU count, bulk quantities per product: Drive-in or drive-through
- Low SKU count, perishables, FIFO required: Pallet flow or drive-through
By Space and Budget Constraints
- Maximum selectivity, budget-focused: Selective roll-formed
- Heavy loads or seismic zone: Selective structural
- Space-constrained, moderate budget: Double-deep or drive-in
- Space-constrained, higher budget, LIFO acceptable: Push-back
- Maximum density, FIFO critical: Pallet flow (highest cost)
Combination Strategies
Many warehouses use multiple rack systems in different zones based on product characteristics:
- Fast-movers in selective: High-velocity SKUs in easy-access selective racks near shipping
- Slow-movers in drive-in: Reserve or seasonal inventory in high-density storage
- Perishables in flow racks: Dated products in FIFO lanes
- Overstock in push-back: Excess inventory of medium-velocity SKUs
Installation and Permitting
All systems require proper installation following manufacturer specifications and published structural standards:
- Concrete requirements: Slab thickness requirements depend on load and seismic zone
- Anchoring: Floor anchors per manufacturer specifications; high-seismic zones require additional anchorage
- Plumb and level: Uprights must be plumb within manufacturer tolerances
- Load placards: Permanent signage showing capacity per bay required at end of each row
- Engineered drawings: Stamped drawings by licensed PE may be required for permits
Frequently Asked Questions
What are pallet rack systems?
Pallet Rack Systems are industrial steel storage frames that hold unit loads on beams or rails. DACO lists 100% selectivity and One pallet deep, 100% direct access. MH-USA says accounts for roughly 85% of all pallet rack installations. Western Storage says Selective pallet rack is the most widely used pallet rack configuration in warehouse environments.
What is the most common pallet rack system?
Western Storage says Selective pallet rack is the most widely used pallet rack configuration in warehouse environments and Every pallet position in a selective system is directly accessible from the aisle. MH-USA says accounts for roughly 85% of all pallet rack installations. DACO says 100% selectivity and The most common bay size is 96 inches wide by 44 inches deep.
How deep can drive-in pallet rack systems go?
Apex lists five to 10+ pallets deep per lane and Lane depth 10+ pallets deep. Conesco lists Drive-In (2–4 Deep) on its cost guide. SJF lists 2 to 10+ pallets deep. Apex also lists approximately $200 per position for drive-in.
What bay size is most common for selective pallet rack?
DACO says The most common bay size is 96 inches wide by 44 inches deep. MH-USA says 42″ is standard for a 48″-deep GMA pallet. SourceBySpec lists 1,067 mm (42 inch) deep frame and 1,219 mm (48 inch) deep GMA. Reynolds says Standard selective racking typically supports 2,500-5,000 lbs per beam level.
How much does used selective roll-formed pallet racking cost per position?
Conesco lists $20–$50 for used Selective (Roll-Formed) with 50–70% savings on its cost guide. Conesco also lists Drive-In (2–4 Deep) used at $85–$160. MH-USA separately says typically costs $40–$80 per pallet position for a standard 3-level setup and Selective rack starts at roughly $150–$300+ per pallet position.