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, Iíll focus just on the idea of concrete floor surface profile.
profile has to do with its contour. Technical guidelines will commonly refer to proper surface profile but, what exactly
does that mean? Taken on itís 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 substrateís surface.
An easy way to
illustrate the idea that the area of a surface isnít necessarily limited to its
initial state is the image of a piece of tin foil thatís 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,
youíd 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
A mistake that both
novice installers and professionals who are new to high performance coatings
(or those who havenít 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 arenít fully descriptive terms and ultimately, theyíre 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
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 manufacturerís guidelines. When proper profiling is achieved, it will
contribute to maximizing the full benefits of the coatingís adhesion potential.
Creating the right substrate conditions, including profile, is the coating
installerís first responsibility.