Floor surface profiling is generally defined and understood as a sub-category of onsite Floor Surface Preparation. Surface preparation involves other aspects in addition to profiling, including the removal of all dust, debris and contaminants of any kind. But here, I’ll focus just on the idea of concrete floor surface profile.

A substrate’s profile has to do with its contour. Technical guidelines will commonly refer to proper surface profile but, what exactly does that mean? Taken on it’s own, the phrase means nothing specific and it should always be quantified according to both, the coating material being used and the floor substrate that will be coated or sealed. What can sometimes sound like major league dump-and-run sound bites coming from a coatings formulator or manufacturer may actually be true: debonding, full-scale delamination and other ugly consequences of an improperly or inadequately profiled surface will often stem from a wrong, careless or an uninformed approach to profiling.

In the case of most two-component, high performance coatings, the proper substrate profile means, first and foremost, that the concrete has an added dimension of surface area, as opposed to having a flat, smooth, closed surface like a pane of glass or a hard, power-troweled concrete surface. A perfectly flat and closed surface offers less surface area for contact with the coating. On the other hand, a substrate that has more exposed surface area will give the coating more points of contact and, as a general rule, the adhesion rate of the coating will tend to increase.   

Adhesion of all types of floor coatings and sealers depends, in part, on optimal surface area contact in order to stay in place. But, catalyzed polymer coatings (usually, a two-component, crosslinking material like an epoxy, a polyurethane or a similar material) need the surface profile to offer anchoring points through some degree of porosity (openness) in the substrate’s surface.

An easy way to illustrate the idea that the area of a surface isn’t necessarily limited to its initial state is the image of a piece of tin foil that’s been wadded to the size of a baseball. The outside surface of a ball of smooth foil the size of a regulation baseball has an area of about 27 square inches. But, if you were to completely open that same ball of foil, smoothing and flattening it, you’d find that the surface area increases exponentially to somewhere between 900 and 1,200 square inches (depending on how determined you were when you compacted it!).

A mistake that both novice installers and professionals who are new to high performance coatings (or those who haven’t yet experienced an adhesion failure) can make is that a rough or textured surface is good enough because it does, in fact, offer more surface area than a flat surface. However, rough or textured in and of themselves aren’t fully descriptive terms and ultimately, they’re not measurable. The proper texture for a two-part polymer coating should always include some degree of deliberate porosity and the porosity should be visible. The foil ball example in the paragraph above shows how the surface area of an object can increase by opening it. An open profile will give added surface area for the coating in the form of anchoring points.

For the purpose of enabling the maximum adhesion rate of a coating to a concrete floor surface, the coatings installer should always be prepared to increase surface profile by opening the concrete surface. Rarely, if ever, should a floor coating be applied without preparing the substrate specifically for the particular type of coating to be applied.

Different methods exist to achieve the right surface profile because floor coatings take many different forms. Sealers (0-3 mils), thin film (4-10 mils), high build (10-40 mils), self leveling (50-125 mils) and overlays (125-250 mils) are all examples of different forms that a polymer floor coating can take. Each type of coating will have a different, optimal surface profile rating which should be specified in the manufacturer’s guidelines. When proper profiling is achieved, it will contribute to maximizing the full benefits of the coating’s adhesion potential. Creating the right substrate conditions, including profile, is the coating installer’s first responsibility.