The Five Main Pallet Racking Types, Compared Side by Side

Two upright frames, a pair of beams between them, and pallets sitting one deep facing an aisle. That simplicity is why selective rack fills most warehouses. A forklift can reach any position without disturbing another, so order picking, cycle counts and lot recalls are all straightforward.

The cost of that access is floor space. Every row needs an aisle in front of it, so a large share of the building is travel lanes rather than storage. Double-deep selective, with pallets two deep and a reach truck with extending forks, recovers some of that space while keeping most of the access.

Selective rack fits any clear height: a lower flex building might run three or four levels, a tall bulk building six or more. The components are standard, easy to repair, easy to reconfigure when products change and the easiest to buy or sell second-hand.

If you cannot say clearly why you need something denser, start here. Most operations that switch to a dense system still keep selective rack for the bulk of their SKUs.

Drive-in rack removes the aisles between rows. Pallets sit on rails, and the forklift drives into the lane to place or retrieve them. The result is one of the densest ways to store pallets without moving parts.

Because the truck enters from one side only, the last pallet in is the first out. That is fine for products where age does not matter, or where each lane holds one product and one lot. It is a problem for mixed lanes, where getting to the back means moving everything in front.

Drive-through rack is open at both ends: load from one side, unload from the other, and rotation becomes first-in, first-out. It uses more floor than drive-in because each end needs an aisle.

Driving inside the rack means more contact with uprights, so guide rails, good lighting and trained operators matter. The rails and columns concentrate load on the slab, so check slab capacity, particularly in older buildings. Freezers are a classic use, because refrigerated space is expensive enough to justify the density.

In push-back rack, pallets ride on nested carts or rollers on a slight incline. A new pallet pushes the ones already there further back; removing the front pallet lets the rest roll forward. The lane is loaded and unloaded from the same aisle, and the front position is always full.

Each lane holds one product, several pallets deep, with a separate lane on every level. That gives far more SKU faces than drive-in at similar depth, and the forklift never enters the rack, which reduces damage.

Standard counterbalance and reach trucks can work push-back, so no special equipment is needed. The carts and rails do add cost per position compared with selective rack, which is why it pays back best where height allows several levels of lanes.

Rotation is last-in, first-out, so it suits products where lot order does not matter.

Pallet flow lanes slope gently from a loading aisle to a picking aisle. Pallets roll forward on wheels or rollers, controlled by speed brakes, so the oldest pallet always arrives at the pick face first. Loading and picking happen in separate aisles, which keeps the two activities out of each other’s way.

It is the natural choice for food, beverage, pharmaceuticals and anything else where first-in, first-out is required rather than preferred. The pick face refills itself, which suits high-volume operations.

Flow lanes depend on consistency. The floor must be level enough for the designed pitch to work, pallets must be in good condition, and the range of pallet weights must suit the brakes. A lane designed for heavy pallets can let light ones stall, and the reverse can let heavy ones run too fast. Share your real pallet weights and types during design.

In freezers, confirm wheels, brakes and lubricants are rated for the temperature.

Cantilever rack has columns down the middle with arms reaching out on one or both sides, and no front uprights. Long material can be loaded from the side by forklift or side-loader without threading it between posts.

It suits pipe, tubing, bar stock, lumber, conduit, sheet goods and rolled material. Contractor yards, steel service, building supply and plant maintenance stores all use it.

Capacity is rated per arm as well as per column. Every arm has its own limit, and exceeding one arm fails that arm even if the column total is fine. Spread long loads over enough arms that they do not sag between supports.

Outdoor cantilever is a structure exposed to weather and must be designed for wind at its location, which is higher near the coast. Galvanized finishes are common for outdoor installations.