From both an operational and safety standpoint, floor marking is rapidly becoming an intrinsic feature in both factories and warehouses across British industry. Whether defining areas for machinery in a factory, creating storage lanes in a warehouse environment – perhaps for block stacking applications – or identifying pedestrian walkways, factory and warehouse management has, at some stage, to address the issue. The need then to identify the most appropriate means of achieving the desired result for a given installation is becoming extremely important.
The overall aim, when specifying material and method, is the same – to create floor marking that is effective in terms of design, visibility and durability. But given wide variations in application needs and a host of site characteristics, what are the key rules that need to be applied when marking either internal or external floors?
Perhaps not surprisingly the first item on the agenda should be to identify the specific application requirements. For example, is the need based on an operational objective or is it more a health and safety consideration? This in turn may help to assess the likely amount of traffic that the floor marking may be subjected to – both pedestrian and mechanical – and whether or not particular practices, such as pushing and pulling pallets along the floor, is commonplace.
The second key area to be addressed is the flexibility of any markings that are going to be applied, particularly with reference to the required durability and longevity. In many cases this may need to account for the condition of the floor itself.
If an unprepared floor is to be marked – in other words where the floor is not being subjected to any specific ground preparation before painting – a simple one part floor paint is often the optimum solution. Straight and consistent lines can be achieved, typically to a width of 100mm to 150 mm (4in-6in), and with the required installation time relatively short, such a finish can become sufficiently dry within just a few hours, depending upon ventilation and temperature.
Moreover, whilst a specialist line laser machine can be used, application by paint rollers is also adequate – simplifying the process and thus helping to control expenditure.
This means chlorinated rubber coatings are often seen as highly cost-effective – a benefit that is enhanced by there being no need to prepare the floor beforehand. However, if extensive abrasion is anticipated then durability can become an important issue particularly as modern power floated floors do not give the paint anything to key to.
As they are one-part materials and may, under some circumstances, be removed by the use of cleaning solutions, they are frequently not the ideal solution in high usage areas. The positive side of this equation, however, sees this same ease of removal allowing a layout to be readily re-designed as required. Indeed, it also means the customer can undertake his own maintenance as lines can be kept in a reasonable condition by the simple application of more paint – maintaining appearance for little cost.
Where a more durable finish is required, particular considerations need to be addressed – most of which are associated with floor preparation and material selection. A two-part epoxy resin applied to a well prepared floor not only provides significant durability but is also chemically stable making it much more able to accept solvent-based cleaning.
Because ultimately performance depends on adhesion to the floor, if longevity is an issue great emphasis should be focused on its preparation. In almost all cases this work calls for the removal of the power float typically used to give concrete a smooth finish.
Experience has shown that a large shot blast machine with a reduced shot blast area is ideally suited to the majority of applications with the operator following a chalk line to maintain the straightest possible direction. Of course, warehouse floors themselves are rarely 100% true and some element of deviation is, therefore, inevitable – a fact that should be realistically anticipated by the warehouse or factory operator.
With shot blasting complete, the correct application of masking tape can minimise the risk of ‘edge flaking’ occurring although this can also be addressed by actually blasting a wider area than that required for the line mark. Although this may not give a perfectly straight edge to a line, it is often considered the better option compared to line edges which may break up over a short period of time giving the impression that the paint is failing.
In an external environment too, particular considerations arise. Line marking and lane definition here, given the often aggressive weather conditions that applications need to endure, are invariably applied by a line laser. This approach has been widely accepted – it is, for example, the accepted method in North America – and is both a fast and inexpensive way to mark roads and car parks, importantly without large amounts of machinery.
Use over coarse concrete also presents no particular difficulties for this process, especially when compared with thermo-plastics where keying to such a surface may be a problem. However, the latter can often be considered the optimum approach where large core tarmac – with the aggregate 10mm or larger – has been used as the construction material.
The final stage in any line marking application, both internal and external, often sees addition of symbols or characters. Because these cannot be subjected to shot blast preparation, experience has shown the optimum application method is to clean the floor thoroughly and then spray the characters through a template with a clear two-part epoxy coating laid over the top. Images thus produced can then be readily and cost-effectively touched up by a customer using standard aerosol paints.
The impact that carefully designed and applied line marking makes in a warehouse application is becoming increasingly acknowledged, particularly as greater pressure is placed on operational efficiency. In an internal context, the procedure does, for example, lend itself to block stacking applications whereby pallets are placed directly on top of each other – typically up to a height of several metres. Where pallet racking is not available, nor required, this can help to make the most of available capacity – both at ground level and vertically.
With careful stock management, block stacking can be used for both long term and rapid turn-round applications. Often increasingly used in conjunction with alpha-numeric and barcoded floor labels – providing interface with computerised stock management systems – the need to identify pallet positions, similar to the conventional means of defining areas of pallet racking, can thus be readily addressed.
As with all other elements of factory and warehouse design, effective floor marking needs to be fully assessed in order that only the optimum methods and materials are used. Whilst there is a choice under both headings, there are clearly defined benefits and drawbacks associated with each option. In a warehouse environment, it is to the management’s advantage to be fully conversant with the optimum marking solution for their particular needs if the concept is to make as great an impact as possible on overall efficiency. n
Tony Gresty is managing director of ASG Services. Tel: 01925 710923.