Floor load capacity (also called floor bearing capacity) is the maximum weight a floor can support per unit area, expressed in kN/m² or lbs/ft². It is a structural design property determined by concrete strength, slab thickness, and subgrade conditions.

Light-duty warehouses typically support 5–10 kN/m² (100–200 psf). Medium-duty facilities handle 10–20 kN/m² (200–400 psf). Heavy industrial floors may be rated at 30–75 kN/m² (600–1500 psf) or more.

Total Load = (Item Weight × Quantity) + Equipment Weight + Personnel Load. Divide by the occupied floor area to get load per m². Compare this to the floor's rated capacity with an appropriate safety factor.

A safety factor of 1.5–2.0 is standard for warehouse floors. This means the floor capacity must be 1.5–2× the calculated working load. Higher factors (2.5–3.0) are used for dynamic or impact loads.

Common causes include exceeding rated capacity, concentrated loads from racking feet or forklift tyres, poor subgrade preparation, insufficient curing, joint deterioration, and thermal movement cracking.

A loaded forklift creates a highly concentrated point load. A 5-tonne forklift's axle load can exceed 80 kN over a small contact area, generating local pressures far higher than the static floor rating.

Static loads are stationary (stored goods). Dynamic loads come from moving machinery and impact. Dynamic loads apply a multiplier of 1.5–3× the static value for floor design purposes.

Light duty: 100–125 mm. Medium duty: 125–175 mm. Heavy duty: 175–250 mm. Reinforced slabs with steel fibre or mesh can be 200–350 mm for very heavy rack and forklift loads.

Yes. Overlaying with additional concrete, installing steel plates for point loads, improving the subgrade, or adding interlocking floor tiles (for limited areas) can increase effective capacity.

Pallet racking transfers load through narrow base plates. A fully loaded upright can exert 30–80 kN on a small area. Each post base load must be checked against floor bearing capacity.

In the US, OSHA 1910.22 requires floors to be able to support loads. IBC Chapter 16 specifies live load requirements. British Standard BS 8204 and EN 1992 cover European warehouse floors.

Warehouse floor rating signs display maximum uniform distributed load (e.g., 5000 lbs/ft²) and sometimes maximum point load. Never exceed rated limits; consult a structural engineer before adding heavy equipment.