Applications
Cold Storage Floors
Freezer and chiller floors work on insulation, under constant temperature cycling and hard-wheeled traffic. Joint design, curing and threshold details decide whether the floor lasts.
Main floor risks
How should a cold-storage floor be designed for low temperatures, thermal cycling and forklift traffic?
- Joint opening and edge damage as the slab contracts at low temperature
- Cracking from thermal gradients during pull-down and defrost cycles
- Frost heave or vapour problems where insulation and vapour control are compromised
- Damage at door thresholds between temperature zones
- Slow or impossible repairs because the room cannot be warmed up
Loads and operating conditions
- Racking and mobile racking loads on a slab supported by insulation rather than ground
- Forklift and VNA truck wheel loads at low temperature
- Thermal loads from cooling the slab to operating temperature and back
- Restraint from the surrounding building and from slab penetrations
- Concentrated loads at dock and airlock areas
Why conventional saw-cut floors fail here
In a freezer the slab shrinks further than a normal floor because it also cools, so saw-cut joints open wider and stay open. Sealants fail at low temperature, edges are unsupported and forklift wheels break them down; repairs need the room warmed up, which stops operations.
What a jointless design must analyse
- Thermal contraction of the slab over the full temperature range, on top of drying shrinkage
- Insulation stiffness and the load spread through it to the base slab or ground
- Reinforcement or post-tensioning strategy to keep contraction cracks closed
- Curing and construction sequence before the room is cooled
- Threshold and dock details between temperature zones
Where construction joints are still required
- Construction joints at pour limits, detailed for low-temperature movement
- Isolation joints at columns and penetrations through the insulated floor
- Threshold joints at doors between freezer, chiller and ambient areas
- Movement joints matching the building structure where present
What BICP provides
- Preliminary review of the floor build-up and temperature zones
- Detailed analysis of thermal and shrinkage effects, slab thickness and joint layout
- Joint and threshold detail engineering for doors and docks
- Armoured joint specification inputs for the remaining joints, supplied through SHENTE
Questions engineers ask
- Why do freezer floor joints open more than joints in a normal warehouse?
- A freezer slab shrinks from drying like any other slab and then contracts again as it is cooled to operating temperature. The two movements add up, so joints open wider and stay open while the room is cold.
- Why is repairing a cold-store floor so disruptive?
- Most repair materials need the slab warmed up to cure, and warming a freezer means stopping operations and moving stock. Designing the joints and crack control correctly at the start avoids that cost.
- What is different about a slab on insulation?
- The insulation is softer than a prepared subbase, so loads spread differently and the slab deflects more under rack legs and wheels. Slab thickness, reinforcement and joint load transfer have to be analysed for that support.
- How should door thresholds between temperature zones be handled?
- Thresholds are where the floor build-up, the temperature and the traffic all change at once. They need a dedicated joint and edge-protection detail rather than a standard contraction joint.
Related projects
Yantian Port Cold Chain Service Warehouse Project
After project completion, the 12m×12m large-span layout effectively reduced the number of internal columns, enhancing flexibility in rack arrangement and meeting the diverse storage needs of port cold chain transit operations. The 64m structural height of this high-rise cold storage facility was among the highest for similar completed projects in China at the time, validating the engineering applicability of large-span post-tensioned flat slab systems in high-rise cold chain buildings.
View project →Xinrongmao Cold Chain Project
On completion, the post-tensioned wide shallow beam scheme met the structural safety requirements for heavy loads while providing the structural space the automated racking system needed. Racking installation proceeded according to the coordinated design, with no rework caused by conflicts between the structure and the racking layout. Compared with a conventional beam-and-slab frame, the storey height was reduced by about 500mm; compared with a flat slab, punching shear risk at the column heads is easier to control and structural safety is higher. The design passed structural review and removed the owner's concerns about structural safety. The project offers a reference for newly built cold storage with heavy floor loads and high clear-height requirements, balancing structural safety and clear height. The post-tensioned wide shallow beam scheme suits cold chain projects where floor loads are heavy, the punching shear margin of a flat slab is insufficient and clear height matters, as well as smart cold storage that must match automated racking precisely.
View project →Suzhou Tianhuan Phase II C# Cold Storage Project
The large-span post-tensioned flat slab system effectively reduced the number of internal columns on each floor, improving rack layout flexibility for multiple temperature zones and enhancing warehouse management efficiency. The floor height advantage of the post-tensioned flat slab system, compounded across 12 stories, positively impacted overall building height and volumetric efficiency.
View project →Next step
Submit your project
Send the floor area, the racking and equipment loads, the operating conditions and the issue you most want to resolve. The preliminary review is free and tells you whether a jointless design route is worth analysing.