Floor loading in kN/m² is the load each square metre of floor is designed to carry: 9.81 kN/m² equals one tonne per square metre, so 10 kN/m² is about 1.02 tonnes. Ratings differ by area; one developer’s sheet gives its factory floor 10 kN/m² and its warehouse area 2.5. Pallet racking also puts its load down through each base plate, so check the rack supplier’s figures against the slab.
In this piece7 sections
What does kN/m² mean on a factory specification sheet?
kN/m² (kilonewtons per square metre) is the load each square metre of floor is designed to carry. One kilogram-force is the weight of a kilogram under standard gravity of 9.806 65 m/s², so one tonne on a square metre is about 9.81 kN/m², and 10 kN/m² is about 1.02 tonnes per square metre.
| On the sheet | Converted |
|---|---|
| 2.5 kN/m² | about 0.25 tonne/m² |
| 10 kN/m² | about 1.02 tonnes/m² |
| 1 tonne/m² | about 9.81 kN/m² |
| 3 tonnes/m² | about 29.4 kN/m² |
| 4 tonnes/m² | about 39.2 kN/m² |
The sums: kN/m² ÷ 9.806 65 = tonnes per m²; tonnes per m² × 9.806 65 = kN/m².
Why is one part of the same factory rated so differently from the next?
“Warehouse” on a plan is not a heavier floorOn this sheet, the area marked warehouse carries the same rating as the office. Where heavy racking goes depends on that area’s own figure. See Sunsuria Kejora Business Park.
What does pallet racking do to a warehouse floor?
Racking does not only spread weight over the floor. The UK Health and Safety Executive’s warehousing guide says floors should bear “the general overall load” and “any point loading from stock, either with or without pallet racking”, and that racking should stand on “sound, level floors, capable of withstanding the point loading at each base plate”.
Photo for illustration purposes onlyThe figure per square metre
- What it is
- The floor rating on the specification sheet, in kN/m².
- What it covers
- The general overall load across the floor.
- Where you find it
- The developer’s specification sheet, by area.
The load at each base plate
- What it is
- The weight one racking leg puts down on a small patch of floor.
- Who sets it
- Safe working loads are set by the designers and manufacturers of the racking system, in HSE’s guide.
- What to ask
- The rack supplier’s figure for the load at each base plate.
Planning racking? Send Chris the rack height, the weight of each pallet and the space you need.
WhatsApp ChrisWhat should you check about the floor before you sign?
- The rating for the area the racking goes inNot the best figure anywhere in the building.
- The racking’s load at each base plateFrom the rack supplier, for a structural engineer to check against the slab.
- Whether the floor is levelHSE’s guide has racking on sound, level floors.
What keeps racking safe once it is in?
- The load noticeHSE’s guide wants a clear notice fixed to the racking, stating the maximum load.
- The weight of each palletKnow it before it goes in; never go over the notice.
- Moving a beamAsk the manufacturer first: moving the first or second beam from the bottom is normally the most critical change, in HSE’s words.
- Regular inspectionDamage reduces what racking can carry; HSE’s guide has it inspected regularly.
- UK HSE guidance
- The unit’s specification sheet
- The rack supplier’s figures
- A structural engineer’s check
What else to look at on a viewing is in what to check during a factory viewing; whether the power is enough, in factory power; and floor ratings that differ by unit type, in Welloyd Industrial Park.
Send Chris your rack height, pallet weight, machines and the floor rating you need.
WhatsApp your requirementThis guide sets out published sources and common practice, not engineering advice. Have the supplier and a structural engineer confirm the numbers for your own racking and machines.
Sources (3)
- Sunsuria Kejora Business Park, specification sheet on the official site (read 22 October 2026), for “Loading”: factory 10kN/m2, office 2.5kN/m2, warehouse 2.5kN/m2: sunsuriakejora.com
- Health and Safety Executive (UK), “Warehousing and storage: A guide to health and safety” (HSG76, second edition 2007, free web version), for floors bearing the general overall load and point loading from stock (paragraph 156), racking on sound, level floors capable of withstanding the point loading at each base plate, safe working loads set by the system’s designers and manufacturers, the maximum-load notice and the first or second beam being the most critical alteration (paragraph 634), and damage and regular inspection (paragraphs 641-642): hse.gov.uk
- Wikipedia, “Kilogram-force”, for the force on one kilogram in a 9.806 65 m/s² gravitational field (standard gravity): en.wikipedia.org
Common questions
How many tonnes per square metre is 10 kN/m²?
About 1.02 tonnes. One kilogram-force is the weight of a kilogram under standard gravity of 9.80665 m/s², so dividing a kN/m² figure by 9.80665 gives tonnes per square metre.
How do you convert tonnes per square metre to kN/m²?
Multiply by 9.80665, or about 9.8. Three tonnes per square metre is about 29.4 kN/m² and four tonnes is about 39.2 kN/m², which lets you compare a listing quoted in tonnes with a specification sheet quoted in kN/m².
Is the warehouse area always rated higher than the factory floor?
Not necessarily. On Sunsuria Kejora Business Park's specification sheet the factory floor is 10 kN/m², while the warehouse and office areas are each 2.5 kN/m². Check the figure for the area where the heavy racking will stand.
Is the floor's kN/m² rating enough to decide on racking?
Not on its own. The UK Health and Safety Executive's warehousing guide says racking should stand on sound, level floors capable of withstanding the point loading at each base plate, with safe working loads set by the racking system's designers and manufacturers. Ask the rack supplier for the base plate loads and have a structural engineer check them against the slab.
What is a racking load notice?
HSE's guide says racking should carry a clear notice, securely fixed to it, stating the maximum load and any specified load configurations, and that those limits should never be exceeded. Know the weight of each pallet before it goes into the racking.
Can you move the beams on pallet racking yourself?
HSE's guide says to consult the manufacturer before altering racking, and that moving the first or second beam from the bottom is normally the most critical alteration, always needing a check on the rack's rated carrying capacity.