Cold store racking: what changes below zero
Cold store racking: what changes below zero
Below zero, racking design changes in four ways: every cubic metre costs more to keep cold, so high-density systems become the norm; steel, finishes and floor fixings must cope with frost, condensation and insulated floors; forklifts lose battery capacity and need cold-rated parts; and people need limited exposure, warm breaks and a guaranteed way out. The racking itself is still steel pallet racking, but the brief behind it is different.
This guide covers what to tell your supplier, from layout and finish to trucks and staff, whether you run a chiller near 0°C or a blast freezer far below it.
Key takeaways
- Cold stores favour drive-in, push back, pallet live and narrow aisle layouts, because aisles are expensive to build and to chill.
- HSE notes that blast freezers can run down to −30°C, where protective clothing alone is not enough and warm breaks are needed.
- Condensation and ice at doors and transitions are the main finish risks; galvanised steel is a common choice in wet or freezing areas.
- Cold cuts forklift battery performance, and RTITB warns battery life can fall by up to 35%.
- Many freezer floors have insulation and heating below the slab, so anchor depths must be checked before drilling.
Why cold stores favour high-density racking
In a cold store, space is the most expensive thing you have. Every square metre of insulated building costs more to build than ambient warehouse space, and every cubic metre of air has to be chilled around the clock. The fewer aisles you have, the more of that cost goes into stored pallets rather than empty air.
That is why cold stores often use high-density systems. Drive-in racking stores pallets many deep in lanes the truck drives into. Push back racking stores several pallets deep on carts or rollers. Pallet live racking uses gravity rollers to feed pallets first in, first out, which suits date-coded food. Narrow aisle racking keeps selective access while trimming aisle width. The worked example below shows how much floor each layout gives to racking rather than aisles.
The choice between systems depends on stock rotation. Drive-in and push back are last in, first out unless the lanes are loaded and emptied from opposite ends, which suits high volumes of few lines. Pallet live keeps strict first in, first out. Our guide to drive-in vs push back vs pallet live racking compares them in detail, and our high-density racking range covers each type.
The temperatures that shape the design
Cold store temperatures cover a wide range, and each band changes the brief. Food law requires chilled food to be kept at 8°C or below (GOV.UK, Food hygiene for businesses). HSE's guidance on chilled and frozen products says work in chillers around 0°C usually needs only suitable clothing and normal breaks, while blast freezers running down to −30°C need more, because protective clothing alone is not enough (HSE, Chilled and frozen food products).
For comparison, HSE's guidance on workplace temperature suggests at least 16°C for indoor workplaces, or 13°C where work involves serious physical effort (HSE, Cold stress). BS 7915, the British Standard on working practices in cold indoor environments, treats air at 12°C or less as a cold environment and applies to places that are cold by design, such as cold stores (BSI Knowledge, BS 7915). Tell your racking supplier the operating temperature of each chamber, because it affects the finish, fixings and handling equipment.
Steel, finishes and floor fixings below zero
The racking frames and beams in a cold store are the same basic components as in an ambient warehouse, but three details change.
Condensation and frost
Moisture is the main enemy, not the cold itself. Warm, damp air entering through doors condenses on cold steel and can freeze, especially near doors, dock levellers and transitions between chambers. Powder coating protects well until it is chipped. In areas that are often wet or icy, galvanised pallet racking is a common choice because the zinc coating protects cut edges and chips better than paint.
Steel at low temperature
Steel becomes less tough as it gets colder. For blast freezers and very low temperature stores, ask the supplier to confirm that the steel grades and connections are suitable for the operating temperature. BS EN 15629, the specification standard for steel storage equipment, lists the environment as information the specifier must provide (BSI Knowledge, BS EN 15629), so state the temperature on the enquiry, not just the dimensions. The design itself follows the same principles as ambient pallet racking under BS EN 15512:2020 (BSI Knowledge, BS EN 15512).
Insulated and heated floors
Many freezer floors are built with insulation and a heated layer beneath the slab to stop the ground freezing and heaving. Anchors drilled too deep can damage that layer. Before installation, get the floor build-up drawings and confirm the maximum drilling depth, then choose anchors that suit it.
Forklifts and handling in the cold
Cold changes how trucks perform, which affects the racking layout. RTITB, the UK workplace transport training body, says cold store operations can cut battery life by up to 35%. Its advice includes choosing trucks with cold-rated components, parking and charging them outside the cold room, charging batteries above 10°C, and passing trucks through a low-humidity area at about 0°C when leaving sub-zero areas to limit condensation (RTITB, 8 steps for efficient cold store forklift operations).
For the racking, that means planning truck routes, charging areas and transition zones as part of the layout, not after it. Enclosed heated cabs help drivers work full shifts, but they reduce visibility, so allow generous clearances at beam level and protect frames at aisle ends. Our guide to warehouse aisle widths for each forklift type explains how truck choice sets aisle width.
People: exposure, escape and access
The racking layout must work for the people inside the store. HSE's guidance says walk-in chillers and freezers need means of escape in case someone is trapped: doors should open from inside, the door and its opening device should be visible when closed, and trapped-person alarms may be appropriate (HSE, Chilled and frozen food products). Keep racking clear of door swings, escape routes and alarm points, and make sure lighting reaches the end of every lane.
Exposure also limits how long people can spend picking or inspecting. High-density systems that keep people out of the chamber, such as drive-in operated from a reach truck cab, can reduce time in the cold compared with layouts that need hand picking at height.
How to brief your supplier
A cold store enquiry needs more information than an ambient one. The table shows what changes.
| Item | Ambient warehouse | Cold store: what to add |
|---|---|---|
| Temperature | Not usually stated | Operating temperature of each chamber |
| Finish | Powder coated | Galvanised where wet or icy; confirm coating suitability |
| Floor | Slab thickness and grade | Insulation and heating layer, maximum drilling depth |
| Layout | Selective access often preferred | High-density options and stock rotation rules |
| Trucks | Truck type and lift height | Cold-rated trucks, cabs, charging and transition areas |
| People | Normal access | Escape routes, door clearances, warming areas |
Inspection needs extra thought too. Frost and poor light make damage harder to see, and inspectors wearing heavy gloves and clothing work more slowly. Plan inspections when chambers can be partly emptied, and fit protection where trucks most often strike: our guide to rack protection explains where guards and barriers go. For drive-in layouts, see our drive-in pallet racking.
Frequently asked questions
What type of racking is best for a cold store?
High-density systems such as drive-in, push back, pallet live and narrow aisle racking are common, because they reduce the area spent on aisles that must be built and chilled. The right one depends on how many product lines you hold and whether you need first in, first out.
Should cold store racking be galvanised?
It is a common choice where steel is often wet or icy, such as near doors and transitions. In stable, dry freezer chambers a powder-coated finish can work, but chips must be repaired. State the conditions so the supplier can advise.
Does cold affect forklift trucks?
Yes. RTITB says cold store operations can reduce battery life by up to 35%, and recommends cold-rated trucks, charging above 10°C and managing condensation when trucks move between temperatures.
Can racking be anchored into a freezer floor?
Yes, but check the floor build-up first. Many freezer floors have insulation and a heated layer under the slab, so anchor depth must stay within the limit the floor designer gives.
Send us the chamber size, operating temperature, floor build-up and truck type, and we will propose a cold store racking layout with a drawing and quote.
Sources
- HSE: Chilled and frozen food products, workroom temperatures
- HSE: Temperature in the workplace, cold stress
- GOV.UK: Food hygiene for businesses, chilling and freezing
- BSI Knowledge: BS 7915:1998 Working practices for cold indoor environments
- BSI Knowledge: BS EN 15629 Specification of storage equipment
- BSI Knowledge: BS EN 15512:2020 Adjustable pallet racking systems, principles for structural design
- RTITB: 8 steps for efficient cold store forklift operations
