How Pallet Racking Works
Pallet racking stacks pallets in vertical rows using uprights (the columns), beams (the horizontal supports), wire decking or pallet supports, and row spacers. Forklifts move pallets in and out. Done right, racking 2–3× your usable storage compared to floor stacking.
The Seven Pallet Racking Systems
1. Adjustable Pallet Racking (APR)
The most common system. Beam height adjusts to match your product. Forklifts have direct access to every pallet. Best for brands with many SKUs and moderate velocity.
Two subtypes:
- Double Deep APR: Pallets stored two deep. Doubles density but requires a reach truck and you can only access the back pallet after pulling the front one.
- Very Narrow Aisle (VNA): Aisles as narrow as 5–6 feet. Requires specialized turret trucks. Highest density of any selective racking.
2. Drive-In Pallet Racking
Forklifts drive into the rack to retrieve pallets. Last-In/First-Out (LIFO) flow. Best for brands with very few SKUs in extremely high quantities (think canned goods, paper products). Bad for ecommerce brands with many SKUs.
3. Drive-Thru Pallet Racking
Like drive-in but with separate entry and exit. First-In/First-Out (FIFO) flow. Useful for perishables or date-sensitive inventory.
4. Live (Gravity Flow) Pallet Racking
Pallets sit on inclined rollers. Load at the back, gravity rolls them forward to the pick face. FIFO. Excellent for high-velocity SKUs but expensive to install.
5. Push-Back Pallet Racking
Similar to live racking but LIFO — pushing in a new pallet pushes the others back. Same loading/unloading face. Higher density than selective, lower than drive-in.
6. Mobile Pallet Racking
Entire racks slide on floor-mounted tracks. Aisles only exist where needed. Up to 80% more storage per square foot than fixed racking. Expensive — typically used in cold storage where space costs are extreme.
7. Multi-Tier Pallet Racking
Vertical mezzanine of multiple manual-pick levels accessed by stairs. Great for high-vertical warehouses with light-to-medium goods. Common for ecommerce small-parts picking.
Bonus: Carton Flow Racking
Not technically pallet racking — carton flow uses inclined rollers for individual cartons rather than full pallets. Standard in ecommerce pick faces because it puts the right SKU at the picker's eye level with gravity-fed replenishment behind.
Which System Does Your Brand Need?
The answer depends on three variables:
- SKU count: Many SKUs → selective APR. Few SKUs → drive-in or push-back.
- Velocity: High velocity → live or carton flow. Low velocity → APR or double deep.
- Date sensitivity: FIFO required → drive-thru, live, or carton flow.
Why This Matters When Choosing a 3PL
When you tour a 3PL, look at the racking. A warehouse with only drive-in racking will struggle with multi-SKU ecommerce. A warehouse with only floor-stacked pallets is operating below industry standard and will eat into your storage budget. A modern ecommerce 3PL will typically blend APR for case-pick reserve with carton flow at the pick face.
At Reconxx, our Statesville facility uses selective APR for reserve, carton flow for high-velocity ecommerce picks, and mezzanine multi-tier for small-parts SKUs — giving us both density and pick speed. Want a tour? We're happy to walk you through.