Warehouse Racking Loads and Slab Design

Warehouse racking concentrates load on baseplates. Slab thickness, reinforcement, and joint detail must all match the racking layout — and changing layout later usually means new slab.

Typical racking loads

• Selective pallet racking: 30–70 kN per upright base
• Drive-in racking: 50–120 kN per base
• VNA (very narrow aisle): higher point loads, plus narrow-aisle truck wheel loads
• AS/RS (automated storage retrieval): foundation loads from rails and crane

Slab thickness for typical layouts

• Selective racking, 3-tier: 180–230mm slab
• Selective racking, 6-tier: 220–300mm slab
• VNA: 250–350mm slab
• AS/RS: special design, often piled foundations

Surface tolerance

VNA racking requires extremely flat floors to allow rail-guided trucks at speed. TR34 / SANS 10100 (industrial floor) DM1 specification typical (4.5 mm tolerance over 300mm). Achieving this requires laser-guided pour and shake-on hardener finish.

Joint detailing

• Saw-cut joints positioned between racking baseplates, never under
• Armoured joint profiles under wheel paths
• Doweled construction joints for load transfer

Future-proofing

If racking layout might change:

• Design slab for highest likely load
• Avoid layout-specific reinforcement
• Plan joint layout for multiple racking grids

Compatibility check

For every new racking install, the slab should be assessed:

• Cores taken to measure thickness
• Compressive strength tested
• Cover meter survey for reinforcement
• Layout plan checked against slab capacity

MCFAR designs warehouse floors and assesses existing slabs for new racking.

Frequently Asked Questions