Solution Features and Benefits
• A total flooring solution with single point liability for ‘Peace of Mind’.
• CoGri Korea has experience designing and constructing floors for temperatures down to -55oc in Korea.
• Low maintenance floor if JF-SOG Wearing Slab is applied.
• Wearing Slab can also be constructed up to TR-34 Superflat tolerances.
Design and Specification
Constructing a high quality Cold Store floor for operating temperatures down to -30oc – sometimes lower, is highly specialised work. Especially for Freezer stores, the floor must be constructed right first time and require very low maintenance as floor repairs are specialised, expensive and sometimes very disruptive to the facility operations. The Architect and Client must seek the advice on a technically competent Cold Store flooring specialist as early as possible in the planning stage, and ensure that a very detailed specification is agreed, which should include all components related to the flooring.
The whole of the floor, from the foundation to the Wearing Slab must be considered as one component, working together. Special attention must be given to:- structural support, insulation type and installation, Wearing Slab detailing and performance of materials. The general system for a Freezer floor is Base Slab – Heater Mat – Insulation then Wearing Slab with Slip Membranes and Vapour Barriers between the layers. If the soil is suitable for a Ground Supported slab, a SOG as detailed in Solution LP-SOG can be applied as the Base Slab, in which case the typical detail may be:
Alternatively the Base slab can be a suspended slab; most importantly it must be constructed as flat and level as possible – TR-34 ‘FM2’ is recommended as the tolerance may effect the tolerance of the insulation which will effect the performance and durability of the Wearing Slab. In some cases it may be possible for forego the Base Slab and design the Wearing Slab as the structural load, although in such cases it is critical to ensure that the Sub-Base is well protected from freezing.
It is generally recommended that a Heater Mat with protection screed is installed to stop the Sub-Base from freezing, although typical Cold Store designs in Korea do not provide this. Without a Heater Mat, the use of a good quality insulation material is even more important to ensure the efficiency of the Refrigeration system and protect the Sub-Base from Freezing. As the Wearing Slab is generally designed and constructed as a Slab on Grade (refer to LP-SOG for details), the insulation material must be installed as flat and level as possible to prevent any restraint to Drying Shrinkage in the Wearing Slab concrete which would result in cracking.
The insulation material must also be capable of providing sufficient structural support. Although Spray Applied Polyurethane Foam insulation is typically used in Korea, it is impossible to control the finished tolerance and an additional layer of levelling mortar may be required. From the experience of CoGri Korea, with PU Foam it is also difficult to ensure uniform support to the Wearing Slab.
Therefore the use of High Density Extruded Polystyrene Insulation Boards is highly recommended by CoGri Korea, with a compressive strength of greater than 4.0 Kg f/ cm2 and a typical thickness of 150 to 200 mm – for Freezer Floors. Special detailing at all interfaces is critical and this should be recommended by the Refrigeration supplier where possible.
Detailing of the Wearing Slab is important and calculations should be provided to check the anticipated opening of Free Movement joints, which can be expected to open up more than normal. In a heavily trafficked warehouse such joints need to be carefully designed as it is not always advisable to cast in place normal steel Armoured Joint systems. Due to the higher thermal movements expected in Freezer Floors, attention to Load Transfer systems and other serviceability concerns is even more important than normal. Obviously Special Joint Sealants are required which may need to be installed at the operating temperature depending on the use of the Freezer Insert Photo CS-1 Store.
Secondary reinforcement for the Wearing Slab can be provided by Steel Fabric or Steel Fibres (a Dry Shake Topping is recommended). A JF-SOG (Joint Free Slab on Grade) has particular benefits for Freezer floors due to the elimination of joints and being a low maintenance solution.
Contact CoGri Korea for a detailed sample specification for Freezer Floors.
Construction Methodology
Pre-construction planning is critical to the success of the project and detailed discussions between the Client, Architect, Main Contractor, CoGri Korea and other Specialists involved, are required from an early stage. The Base Slab should be ideally constructed by Laser Screed or Copperhead in order to achieve the recommended tolerance of TR-34 FM2, the choice depends on the type of reinforcement required. After the tolerance and levels are checked, the Heater Mat (if required) and Insulation can then be installed by Specialist applicators, although it is advisable to allow the Base Slab to cure for some time first.
The Wearing Slab can be constructed using LP-SOG or SF-LS methods, depending on the storage system and specification required. If conventional racking systems are used, to achieve tolerances up to TR-34 FM2, the CoGri Korea ‘Copperhead’ Laser Screed can be used with high flotation tyres to prevent damage to the insulation. With its many years of experience designing and constructing Freezer Floors, the CoGri Group has developed various techniques to construct Freezer Floors to the highest possible tolerances, using Long Strip construction and specially designed Construction Joint systems. After the floor is constructed and Compliance Testing carried out, the Wearing Slab should be allowed to Cure for at least 28 days prior to gradual lowering of the Freezer Store to its operating temperature.
CoGri Korea and the CoGri Group are specialists in the design and construction of Freezer Floors and provide a complete professional service. In 2006, CoGri Korea constructed a Freezer type floor to an Environmental Test Facility for the Korea Agency for Defense Development. The temperatures in the chamber will vary from +55 oc to – 55oc within 24 hours, making it one of only two or three such facilities in the world.
CoGri Korea provided to total flooring solution to the Client including Design, Construction and Testing, again proving just why CoGri Korea is ‘Your Quality Flooring Partner’.
