Every racking system is the same trade in different proportions: how much you store against how easily you can reach any given pallet. Selective racking gives you every pallet and the worst density. Drive-in gives you density and takes away access. Everything else sits between.
Density versus selectivity. A selective rack lets you pick any pallet at any time and wastes roughly half the floor on aisles. A drive-in rack stores far more in the same footprint and forces you to move other pallets to reach the one you want.
Which side you should be on is decided by your stock, not by your preference: how many distinct SKUs you hold, how many pallets of each, how fast they turn, and whether they must go out in the order they came in.
That is why the honest version of "which racking is best" is a question about your inventory profile. Work through planning a warehouse layout alongside these pages rather than after them.
Building height and floor slab set a ceiling on what is buildable. Your forklift fleet sets aisle widths, and aisle width often decides the system before anything else does — a reach truck and a counterbalance truck want very different layouts. See forklifts and materials handling equipment.
And the brand you already own constrains what you can extend rather than replace: the major racking brands.
16 guides
Selective is the racking system most Australian warehouses run, and for a reason worth understanding rather than assuming. It puts every pallet within direct forklift reach at the cost of the worst floor density of any system in this silo.
Double-deep racking is the first small step off selective on the density axis: two pallets deep instead of one, in exchange for losing direct access to the back pallet. It suits stock with at least two pallets per SKU and a truck built to reach that far.
Drive-in sits at the density end of the axis this whole silo runs on: the forklift drives inside the rack structure itself, between rails that carry the pallets, and gives up individual pallet access almost entirely in exchange for the best floor density of any forklift-served system.
Push-back racking loads pallets onto inclined nested carts from a single aisle: each new pallet pushes the one behind it further back, and gravity brings the front pallet forward again as they're unloaded. It sits between double-deep and drive-in on density, without a forklift ever entering the lane.
Pallet flow racking loads at one end and picks at the other, riding gravity down a lane of rollers so the first pallet in is always the first one out. It answers drive-in's biggest limitation — no FIFO — without giving up much of the density.
Carton flow racking takes pallet flow's gravity-and-FIFO idea down to the carton level, feeding individual cartons to a pick face instead of whole pallets. It belongs in this silo as a contrast: it's not a pallet system at all, and the density axis doesn't really apply to it the same way.
Cantilever racking swaps front-facing uprights for open arms projecting off a central column, because the whole point of the design is storing goods too long to fit between conventional frames. It doesn't sit on the pallet-racking density axis at all — it's a different problem: length, not pallets.
Narrow aisle racking is selective racking with the aisle narrowed to whatever a very narrow aisle truck needs, not a different bay design. The density gain is real, and so is the price: a purpose-built truck and a floor flat enough to trust it in.
Shuttle racking replaces push-back's gravity carts with a powered, remote-controlled shuttle that carries pallets in and out of a deep lane on command. It reaches depths and speeds neither push-back nor drive-in can match, at real added cost and complexity.
Mobile racking puts entire rows of selective-style racking on motorised carriages running on floor rails, so rows sit closed up against each other and only one aisle opens at a time, wherever it's needed. It's a different move on the density axis to anything else in this silo: it doesn't change the racking, it removes almost all the aisles.
Longspan shelving is the odd one out in this silo: it's built for people, not forklifts. Wide, adjustable shelves carrying hand-loaded cartons, bins and small parts sit closer to industrial shelving than to any pallet racking system on the density axis.
A mezzanine doesn't belong on the density-versus-selectivity axis at all — it's not a racking system, it's a second floor built above the first, and the storage or work that happens on it can run any system in this silo again on that new level.
Both are single-aisle, LIFO-only systems built to squeeze more pallets into less floor, which is exactly why they get confused. Drive-in pushes density further; push-back keeps the forklift out of the lane. The right one depends on how deep your stock actually runs and how much risk you're willing to put inside the rack structure itself.
Selective gives every pallet direct access; double-deep trades some of that access for real density. The decision comes down to one number: how many pallets deep each SKU actually runs, and whether the reach-truck fleet can reach the back one.
Aisle width isn't just a racking decision — it decides which forklift you're running for the next decade. Go narrow and you commit to a guided VNA truck and a flatter floor; stay wide and you keep flexibility at the cost of floor space.
Racking design specifies clearance above and beside every pallet for a reason: placement error, beam deflection under load, and enough margin to actually retrieve the pallet without a fight. How much is a manufacturer's design question, confirmed by a competent person, not a number this page will hand you.