Solvented Epoxy Resin Based Flooring Materials
Solvented / solvent containing epoxy resin flooring materials are now normally regarded as old fashioned and out-dated epoxy resin flooring technology, due to the increased knowledge and understanding of the risks associated with the potential for tainting, VOC’s and flammable materials. However, they are still available and promoted and sold more widely than we would have expected, probably since these are now generally lower cost, but it is important to be aware of and minimise any risks associated with using these high VOC products. At NCC it is now only exceptional circumstances that we would propose using these materials as there are usually alternative solutions with lower VOC’s and flammable risks.
The relatively large quantity of solvent (usually more than 75% pbw of the product), allows and increases ease of application, and produces optimum coverage for contractors in terms of the highest m2/litre. This is not always good for the owners though, as the further the material is spread, the lower the resulting film thickness, measured as its DFT, and therefore this ‘excellent coverage’ is not necessarily the optimum for the finished resin floors performance. However, it must also be said that solvent dispersed resin flooring materials are relatively fast curing (drying and hardening), especially at lower temperatures, when the solvent evaporates much faster than would the water in a comparable water dispersed epoxy resin product. Solvented resin products can also have good abrasion and chemical resistance, even despite their comparatively low dry film thickness (approx. 50-80 microns per coat), which was why this type of material was once widely used to provide economic and effective industrial resin floor coating solutions, especially for storage and logistics facilities. The advantages can be summarised as primarily being their performance and durability in service, at relatively low film thickness, their suitability for use and ability to cure at lower temperatures, and their relatively low sensitivity to moisture as the solvent can displace water in the substrate and allow penetration, where other materials could not. As a result there are still a few of these materials retained in product ranges for use as primers and surface conditioning / adhesion promoting products. Your technical specialist from NCC resin flooring team will advise you when this is a good solution for your projects.
However, despite these positive characteristics and some definite advantages, the nature of the highly volatile and potentially aggressive and environmentally damaging solvents contained in these solvented epoxy resin flooring products (usually from min. 50 to >85% solvent) means that these products are almost all classified as having unacceptably high VOC levels (volatile organic compounds). These VOC’s are released into the atmosphere during application and curing, so they are increasingly restricted, or banned on many industrial sites and commercial premises. Additionally this solvent content always requires that considerable ventilation must be provided, otherwise people working in adjacent areas may also be disturbed or inconvenienced by the smell and odour. Some foodstuffs (particularly dairy products) and other materials can also be sensitive to and even tainted by these VOC solvents, so considerable work and cost would be involved in closures and / or the provision of additional protection to prevent this. Additionally, the good cross-linking of these epoxy resin products that gives them their excellent chemical and mechanical resistance, also turns to a disadvantage when overcoating in eventual refurbishment, as their residual surfaces will need mechanical preparation e.g. by blastcleaning, or solvent reactivation, with all the inherent difficulties and costs of these processes.
Finally, the high levels of solvents are also dangerous because they are generally highly flammable, so solvented epoxy resin flooring products must not be used near any sources of ignition, naked flames or where welding operations take place etc.
As mentioned previously, all of this is technically somewhat unfortunate, especially for sealing exposed concrete or cement screed floors in large open spaces, in factories and warehouses. However these materials can sometimes still seem to be ideal due to their tolerance of cooler application conditions or their apparent initial low price, but this must always be viewed together with the costs of environmental damage and the health and safety risks for not just the flooring contractor, but also any other trades and people working in the facility for the owner. Therefore the additional restrictions and limitations for the use, even in road transport, are valid and we should support them as being in all our interest. – The real total cost of using solvented epoxy resin floor products is now not so attractive and in fact can present significant risk in many ways! Unfortunate from a technical performance point of view, yes maybe – but this is how it is and overall it is right and this has probably also driven the further innovation and development of water dispersed and solvent-free types of epoxy resin flooring systems in the last 10 to 15 years for sure.
Fortunately today, in almost all situations, NCC Resin Flooring Experts are able to recommend a much safer, more environmentally friendly and all round better performing water dispersed epoxy, or solvent-free epoxy products as an alternative, please call any of our offices on 01257 266696 and one of our resin flooring specialists will be pleased to assist you in the selection of the best resin flooring solution for your project.