Resin flooring has a reputation for strength, seamlessness, and long service life, but very little of that reputation actually comes from the resin itself. It comes from what happens before a single drop of resin touches the floor. Preparation is the single most important stage of any resin flooring project, and it is also the stage most often underestimated by anyone who has not specified or installed a resin system before.
At REME Industrial Flooring Ltd, every specification we produce is built around the correct preparation method for the substrate in question, the resin system being installed, and the environment the floor needs to perform in. This article explains why preparation matters so much, walks through the professional methods we use, and outlines what can go wrong when preparation is rushed or skipped.
Why Floor Preparation Determines the Life of the Floor
A resin flooring system is only as strong as its bond to the substrate beneath it. Epoxy, polyurethane, and MMA systems all rely on a mechanical and chemical key between the resin and the concrete. If that key is weak, incomplete, or contaminated, the floor will fail long before its expected lifespan is reached, no matter how good the resin product itself is.
Most of the flooring failures we are called out to inspect, including bubbling, delamination, peeling, and patchy curing, trace back to one root cause: the substrate was not properly prepared before the resin went down. Dust, laitance, old coatings, oil contamination, and excess moisture in the concrete all prevent proper adhesion. Once a resin layer is applied over any of these issues, there is no way to fix the problem without removing the floor and starting again.
This is why a proper specification always begins with an assessment of the substrate, not the resin. The resin is chosen to suit the environment. The preparation method is chosen to suit the substrate.
Assessing the Substrate Before Any Work Begins
Before any mechanical preparation takes place, the existing floor needs to be properly assessed. This typically includes:
- Moisture testing. Concrete that holds excess moisture will trap it beneath a resin layer, leading to blistering and bond failure later on. Relative humidity testing tells us whether a moisture-tolerant primer or damp-proof membrane is required before proceeding.
- Condition survey. We check for cracks, holes, previous coatings, oil or chemical contamination, and general wear. Each of these issues needs a different remedy, and some (such as heavy oil contamination) require a specific preparation method rather than standard grinding or blasting.
- Substrate strength testing. A pull off or tensile test confirms that the concrete itself is strong enough to hold a resin system. If the top layer of concrete is weak or friable, preparation needs to go deeper than a surface treatment.
Only once this assessment is complete can the correct preparation method, primer, and resin system be specified with confidence.
The Main Professional Preparation Methods
Dust Enclosed Shot Blasting
Shot blasting is the industry standard method of preparing concrete floors for resin application, and for good reason. Small steel shot is fired at the concrete surface at high velocity, removing laitance, old coatings, and surface contamination while opening up the pores of the concrete to create a strong mechanical key. Because the equipment is fully enclosed and vacuum assisted, the process is dust free, which makes it suitable for use in occupied buildings and sensitive environments such as food production facilities.
Shot blasting is quick, cost effective, and consistent across large areas, which is why it remains the most commonly recommended preparation method for both new and existing concrete floors ahead of epoxy or polyurethane installation.
Diamond Grinding
Vacuum assisted diamond grinding uses rotating diamond segmented discs to grind down the surface of the concrete. It is particularly useful where a floor is uneven and needs levelling, where access restrictions make shot blasting equipment impractical, or where a finer surface profile is required for a specific resin system.
Diamond grinding is also commonly used around the edges of a room and in corners, where larger shot blasting machines cannot reach, ensuring the entire floor receives a consistent profile rather than leaving weaker, untreated strips around the perimeter.
Scabbling and Planing
For substrates in particularly poor condition, or where a significant depth of concrete needs to be removed, scabbling or planing may be used. These methods use mechanical tools to break up and remove the top layer of concrete more aggressively than grinding or blasting alone. This is typically reserved for older industrial floors with deep contamination, significant surface damage, or an existing coating that cannot be removed by lighter methods.
Hot Compressed Air (HCA) Treatment
Some floors, particularly in workshops, garages, and manufacturing environments, suffer from oil contamination that has soaked deep into the concrete over years of use. Surface grinding alone cannot remove oil that has penetrated below the surface, and applying resin over residual oil will almost always result in adhesion failure.
Hot Compressed Air treatment is the only reliably proven method of dealing with this type of deep contamination. The process forces heated air into the concrete, which burns off surface oil and draws residual oil up and out of the slab. Once the floor has cooled, a low viscosity, solvent free, oil tolerant epoxy primer is applied. As the floor continues to cool, this primer is drawn into the concrete, sealing it and curing more quickly than it otherwise would. Only after this process is complete can a standard resin system be applied with confidence.
Crack and Joint Repair
Cracks, holes, and expansion joints need to be addressed before resin application, not afterwards. Left untreated, movement in the substrate will transfer straight through to the new resin layer, causing cracking or reflective damage in the finished floor. We fill and repair these areas using compounds designed to move in line with the substrate, ensuring the finished floor remains smooth, seamless, and structurally sound.
Primer Selection
Once mechanical preparation is complete, the correct primer needs to be selected and applied. Primers vary depending on the substrate condition, moisture levels, and the resin system being installed. A universal water based epoxy primer might suit a straightforward internal floor, while a moisture tolerant or oil tolerant primer will be required in more demanding conditions. Getting this step wrong is one of the most common causes of early floor failure, which is why primer selection is treated as part of the specification, not an afterthought.
Why Professional Preparation Matters More Than the Resin Choice
It is tempting to focus purely on which resin system looks best on paper, epoxy, polyurethane, or MMA, but the truth is that even the best resin system in the world will fail if it is applied to a poorly prepared substrate. Conversely, a well chosen mid range system installed over properly prepared concrete will consistently outperform a premium system installed over a rushed or incomplete preparation job.
This is also why DIY resin flooring projects so often run into trouble. Achieving a genuinely dust free, fully enclosed shot blast, or correctly diagnosing and treating oil contamination with Hot Compressed Air equipment, is simply not realistic without professional grade machinery and experience. The preparation stage is where the investment in professional installation pays for itself many times over.
How REME Approaches Floor Preparation
Every specification we provide includes the preparation method best suited to the substrate, the resin system specified, and the client’s environment. Depending on the project, this may involve dust enclosed shot blasting, vacuum assisted diamond grinding, scabbling or planing, Hot Compressed Air treatment for oil contaminated floors, or a combination of methods across different areas of the same site.
All of our resin systems are developed and guaranteed by leading manufacturers including Sherwin Williams, Resdev, ESP, and Sindec Chemicals, and every installation conforms to BS5750. That standard of finished product depends entirely on the preparation work carried out underneath it.
If you are planning a resin flooring project, whether for an industrial unit, a commercial kitchen, a warehouse, or a domestic garage, we offer a completely free, no obligation site survey and specification. Our team will assess your existing floor, identify the correct preparation method, and recommend the resin system best suited to your environment and budget, Get in touch with our team to arrange your free survey.
