Not all pallet rack is the same. The type of rack system you choose determines how much you can store, how quickly you can access it, and how much it costs per pallet position.
This guide compares every major type of pallet rack system, explains how each one works, and helps you choose the right system for your warehouse operation.
Selective Pallet Rack
Selective rack is the most common pallet rack system in North America. Every pallet position is directly accessible from the aisle — no need to move other pallets to reach the one you need.
How It Works
Horizontal beams connect vertical upright frames, creating shelf levels for pallets. Forklifts place and retrieve pallets from the aisle side. Standard configurations use two pallets deep (back-to-back rows) with aisles between each row.
Advantages
- 100% selectivity — every pallet is immediately accessible
- Lowest cost per pallet position
- Simple design, easy to install and reconfigure
- Works with any standard forklift
- Easy inventory management — FIFO (first in, first out) is natural
Disadvantages
- Lowest storage density — aisles consume significant floor space
- Typically uses only 50-55% of available floor area for storage
Best For
Operations with many SKUs, low pallets per SKU, or where every pallet must be individually accessible. This is the right choice for most warehouses.
Double-Deep Pallet Rack
Double-deep rack stores pallets two-deep on each side of the aisle, eliminating one aisle for every two rows of selective rack.
How It Works
Standard selective rack uprights are spaced to hold two pallets deep. A double-deep reach truck with an extended fork reaches over the front pallet to place or retrieve the rear pallet.
Advantages
- 20-30% more storage than selective rack in the same footprint
- Still provides good selectivity — two pallets deep is manageable
- Uses the same beam and upright components as selective rack
Disadvantages
- Requires a double-deep reach truck ($45,000-$65,000)
- The rear pallet is not accessible until the front pallet is removed
- Best with two or more pallets of the same SKU per position
Best For
Warehouses that need more density than selective but still want reasonable selectivity. Works well when you have 2-4 pallets of many SKUs.
Drive-In and Drive-Through Rack
Drive-in rack eliminates aisles between rows entirely. The forklift drives into the rack structure to place and retrieve pallets on rails.
How It Works
Uprights are connected by horizontal rails (not beams) at each storage level. The forklift drives into the lane, lifts the pallet above the rails, drives forward to the deepest open position, and sets the pallet on the rails. Drive-in rack has one entry point per lane (LIFO — last in, first out). Drive-through rack has entry points on both ends (FIFO capable).
Advantages
- Up to 75% floor utilization — dramatically more storage than selective
- Excellent for bulk storage of identical pallets
- Relatively low cost per pallet position for the density gained
Disadvantages
- Very low selectivity — only the front pallet in each lane is accessible
- LIFO inventory management (drive-in) — not suitable for perishable or date-sensitive goods
- Slower put-away and retrieval — forklift must drive into the structure
- Higher damage risk — forklifts operating inside the rack structure can hit uprights and rails
Best For
Bulk storage of homogeneous product — seasonal inventory, raw materials, finished goods with few SKUs and many pallets per SKU.
Push-Back Rack
Push-back rack stores pallets on nested carts that ride on inclined rails. When you place a new pallet, it pushes the previous pallets back. When you remove the front pallet, the ones behind it roll forward.
How It Works
Each lane has 2-6 nesting carts on rails with a slight incline from front to back. Loading: the forklift places a pallet on the front cart and pushes it back to load the next. Unloading: removing the front pallet lets the remaining pallets roll forward by gravity.
Advantages
- 2-6 pallets deep without the forklift entering the rack
- Faster than drive-in — all operations happen from the aisle face
- Good density improvement over selective (up to 90% more storage)
- Multiple SKUs can be stored in adjacent lanes
Disadvantages
- LIFO inventory management — last pallet loaded is the first retrieved
- Higher cost per position than selective or drive-in
- Cart mechanisms require maintenance
- Limited to 2-6 pallets deep (most common is 3-4 deep)
Best For
Operations with moderate SKU counts and 3-6 pallets per SKU. Excellent for cold storage where maximizing cube is critical and building space is expensive.
Pallet Flow Rack (Gravity Flow)
Pallet flow rack uses inclined roller conveyors within the rack structure. Pallets loaded at the back roll by gravity to the pick face at the front.
How It Works
Lanes are equipped with roller conveyors angled from the loading (back) side to the unloading (front) side. Pallets are loaded from the back and gravity moves them to the front. Speed controllers and separators regulate flow and keep pallets from slamming together.
Advantages
- True FIFO — first pallet loaded is the first retrieved
- High density — up to 20+ pallets deep per lane
- Automatic stock rotation — critical for food, beverage, and pharmaceutical
- Separates loading and picking aisles — reduces forklift congestion
Disadvantages
- Highest cost per pallet position of any rack system
- Roller conveyors require maintenance
- Works best with uniform pallet sizes and weights
- One SKU per lane
Best For
High-volume FIFO operations — food and beverage distribution, pharmaceutical, any product with expiration dates. Also excellent for high-throughput operations where separate load and pick aisles improve efficiency.
Cantilever Rack
Cantilever rack uses horizontal arms extending from vertical columns instead of beams between uprights. This creates open, unobstructed storage levels for long, bulky, or irregularly shaped items.
How It Works
Single or double-sided columns are anchored to the floor. Horizontal arms are inserted at adjustable heights. Products rest directly on the arms without cross-beams in the way.
Advantages
- Stores items that do not fit on standard pallet rack — lumber, pipe, bar stock, furniture, sheet goods
- No front column obstruction — load and unload from the open front
- Adjustable arm heights for different product sizes
- Available in light-duty, medium-duty, and structural heavy-duty configurations
Disadvantages
- Not suitable for palletized storage
- Lower storage density than pallet rack for items that could be palletized
- Arms must be rated for the load — overloading causes deflection and failure
Best For
Lumber yards, steel service centers, furniture warehouses, plumbing and electrical supply, and any operation storing long or odd-shaped items.
Pallet Rack Comparison Table
| System | Depth | Selectivity | Inventory Method | Cost per Position | Floor Utilization |
|---|---|---|---|---|---|
| Selective | 1 pallet | 100% | FIFO | Lowest | 50-55% |
| Double-Deep | 2 pallets | 50% | LIFO | Low | 60-65% |
| Drive-In | 5-10+ pallets | Low | LIFO | Low-Medium | 70-75% |
| Push-Back | 2-6 pallets | Moderate | LIFO | Medium-High | 65-70% |
| Pallet Flow | 5-20+ pallets | Moderate | FIFO | Highest | 70-75% |
| Cantilever | Varies | 100% | FIFO | Medium | 55-65% |
How to Choose the Right System
- Count your SKUs and pallets per SKU — many SKUs with few pallets each points to selective. Few SKUs with many pallets points to drive-in, push-back, or flow.
- Determine FIFO or LIFO — perishable or date-sensitive products require FIFO (selective, flow, or drive-through). Non-perishable goods can use LIFO (drive-in, push-back).
- Calculate space available — limited floor space pushes toward higher-density systems.
- Evaluate throughput needs — high pick rates favor selective or flow rack. Low-turn bulk storage works with drive-in or push-back.
- Budget — selective is cheapest per position. Weigh the cost premium of dense systems against the cost of additional building space.
Many warehouses combine multiple systems — selective rack for high-SKU picking areas, push-back or drive-in for bulk storage zones, and cantilever for odd-shaped products.
Need help choosing the right pallet rack system? Contact Material Handling USA for a free consultation. We provide warehouse design services that include rack system comparison, layout optimization, and detailed storage density calculations.
