What is resin flooring?
Resin flooring generally refers to a liquid applied multi-component resin system applied onto a floor substrate to form a seamless, monolithic surface. The resin systems are commonly based on epoxy, polyurethane (PU), polymethylmethacrylate (PMMA), polyurea or a combination of the above resins. Aggregates may be added in the system to enhance the strenghs, abrasion resistance and skid resistance. Other functional additives or fillers may also be added to the flooring system to give it integral colors (e.g. colored quartz, color chips, etc.) or conductivity (ESD flooring).
What is the difference between epoxy and polyurethane (PU) flooring?
"Epoxy" is a general term representing a broad range of resins based on reacton products of epoxides and hardeners. It is the most common class of resin used in resin flooring, accounting for about 70% worldwide. It has the best balance of properties required in most floorings. It has excellent adhesion to most floor substrates: concrete, stones, tiles, marbles, steel, aluminum, wood, etc. It has excellent chemcial resistance, high compressive, tensile and flexural strengths to withstand the wear & tear of foot and wheel traffics. It can be applied from paper thin to several mm thick or more. It can be solvent free with virtually zero VOC and negligible odor. It is the workhorse in the resin flooring industry.
"Polyurethane (PU)" is the next most popular resin used in the resin flooring industry. PU is a general term representing a broad range of resins based on reaction products of polyisocyanates and polyols. It has excellent elongation, flexibility and toughness. It can be formulated from being a rubber like flooring up to a hard, rigid flooring. It is commonly used for indoor sports flooring or outdoor decking where a flexible, resilient crack-bridging materials is required. However, not all flexible PU flooring will be "crack bridging" (for more info. please see below and click here to find out more on this topic). PU flooring resins, like epoxy resins, are mostly aromatic based. Upon exposure to UV light, it will cause yellowing and chalking on the surface. However, with proper formulation and/or an aliphatic PU top coat, Both epoxy and PU flooring can become equally UV stable for outdoor flooring, decking, and waterproofing applications.
What is "crack bridging" car deck flooring system?
"Crack Bridging" resin flooring is designed to withstand MINOR cracks which may subsequently develop in the floor substrate due to structural movement, concrete shrinkage, themal movement, static or dynamic loading. The resin flooring is supposed to stretch elastically across the cracked substrate without damage. This is especially important for car deck flooring which also serves as waterproofing deck to prevent water seepage to the level below.
For car park decking, it is usually effective for cracks <<2mm. In fact, a lot of crack bridging systems failed at cracks much smaller. The reason for failure can be attributed to both the materials and more importantly, the applicators.
Specifier intuitively thinks if a material has higher elongation (stretches like a rubber band), it will perform better in bridging cracks. Studies have shown that it may not necessarily be true (see our leaflet on "Crack Bridging...). For minor cracks, stiffer materials with higher tensile strength may perform better than flexible, high elongation materials. This is especially true in car decking applications where a flexible, high elongation flooring inherently may not have edaquate tensile and tear strength to withstand the twists & turns of the rubber tyres, causing premature failures in many cases in Hong Kong and overseas.
The applicator is another factor. For a car deck flooring to elongate to bridge cracks, it needs to be at least 4mm thick and applied in multiple layers. Each layer must be installed to strict specifications. Many applicators, for the sake of saving cost, will "alter" the procedures and cut back on materials usage. This is often fatal for car deckings. Once a flexible decking system fails, it will require extensive and costly remedial repair. In many cases, a complete resurfacing may be required.
Therefore, the specifier must be well advised of all the pitfalls and work with a reputable materials supplier and applicator when specifying crack bridging car deck systems.
How important is surface preparation in resin flooring installation?
Surface preparation is of paramount importance in any resin flooring installation. It is estimated that 70% of resin flooring failure may be attributed to improper, or lack of surface preparation. Surface preparation not only affects the bonding and durability of the resin flooring, it may also affect the aesthetics of the finished surface. Proper grinding, shotblasting and substrate repair can make all the difference in the final outcome of the job.
Unfortunately, proper surface preparation may also be the most difficult and expensive part of the installation process. Many applicators either do not have the skiils or the equipment. They tend to take the easy way out resulting in many resin flooring failures.
How do I know what thickness to specify for my resin flooring?
In general, a thicker flooring can withstand higher loading, wear & tear and will last longer. Epoxy flooring installed thickness can range from 0,5mm to 6mm or higher, normally between 1mm and 3mm. For specific job requirement, please contact our sales team for recommendations.
Where can I find technical references or international standards related to resin flooring?
One of the best technical sources for resin flooring can be found in the British Standards (BSI) BS 8204 Part 1 through Part 7. They cover a comprehensive code of practice from screed bases to the wearing sufaces under the main title "Screeds, bases and in situ floorings --". Other reference sources can be found in our Tech Corner page. Other relevant information can be found through ASTM International and American Concrete Institute (ACI).