Floor load capacity is how much weight a warehouse floor slab is designed to carry without cracking or settling. Listings in Latvia usually give one number, such as "5 t/m²". That number describes an evenly spread load, and most warehouse loads are not evenly spread. Before you sign, the question to answer is whether the slab can carry your racking, your goods and your forklifts in the positions your layout puts them.
Distributed load and point load
- Uniformly distributed load (UDL) is weight spread evenly over the floor, stated in t/m² or kN/m² (1 t/m² is about 10 kN/m²). It fits floor-stacked pallets and bulk goods.
- Point load is weight concentrated on a small area: a rack upright on a baseplate of roughly 150 × 150 mm, a machine foot, a forklift wheel. The slab has to resist punching and bending under each of these, which a t/m² figure does not describe.
A simple example shows the difference. Selective racking with 4 beam levels, 2 pallets per level and 1,000 kg pallets holds 8 t per bay. Because neighbouring bays share their frames, each frame carries about 8 t, so each of its two uprights carries around 4 t, plus the steel itself. That is 4 t pressing on a plate smaller than a sheet of A4 paper.
Typical figures in Latvian warehouses
| Building type | Typical design load | What to watch |
|---|---|---|
| Class A, built in the last 20 years | 5 t/m² UDL, designed for racking point loads | Check the stated upright load and the flatness class |
| Class B, refurbished | 2–5 t/m² | Joints, cracks and whether the slab was replaced or only resurfaced |
| Class C, Soviet-era or converted | Often 1–3 t/m², sometimes unknown | Missing documents; slab thickness and reinforcement unknown |
| Upper floors and mezzanines | Far lower, often under 1 t/m² | Not suitable for racking without a structural check |
Floor-stacking needs more than people expect. Three 1-tonne pallets stacked on one 1.2 × 0.8 m footprint put about 3.1 t/m² on the floor directly beneath them, before forklift traffic is added.
Forklifts and floor flatness
Forklift loads are dynamic and concentrated. A loaded reach truck carries its weight on a few small polyurethane wheels, and braking and turning add to the static load. Ask the forklift supplier for the wheel loads of the specific model and give them to the structural engineer with the racking loads.
Flatness matters as much as strength once racking goes high. Very narrow aisle (VNA) trucks lifting to 10–12 m need a floor built to a defined-movement flatness class (for example under EN 15620 or the TR34 classification), because a few millimetres of slope at the wheels becomes centimetres of sway at the top of the mast. A floor that is strong enough can still be too uneven for VNA.
Documents to request
- The floor construction drawings: slab thickness, concrete class, reinforcement or steel fibre content, and the design loads (UDL and point loads).
- The flatness specification and any survey made at handover.
- For an older building without documents: a structural engineer's assessment, which may include coring the slab to measure thickness and concrete strength.
- A record of known defects: cracks, failed joints, settlement near doors or docks.
Viewing gives clues but not proof. Wide cracks, broken joint edges and dips near dock doors suggest problems, but a clean-looking floor can still be too thin for your racking.
If the floor is not enough
Options range from spreading loads with larger baseplates, to re-planning the racking so uprights avoid weak zones and joints, to cutting out and recasting sections of slab. A new topping layer on a weak slab rarely adds real capacity. Agree the solution, cost, schedule and who pays in the lease before you sign; recasting a slab under an occupied warehouse is slow and disruptive.
Taller buildings tend to need stronger floors, so read this alongside the clear height guide and the warehouse classes guide.