Finding blisters or bubbles on tennis court surfaces is a somewhat common
problem, especially on concrete substrates. Many court owners are baffled
by the fact that sometimes the blisters are there and other times they
are not. The first thing they do is blame the resurfacing contractor,
because it was fine before, and now the problem is happening after the
new surface was applied.
Acrylic tennis court surfaces are semi-permeable, or breathable, and
allow small amounts of moisture vapor to transmit through them from
beneath the slab. However, if there are large amounts of moisture trying
to get through, it can create this situation. When a tennis or basketball
court was not built with a proper perimeter drainage system to divert
rain water away, much of the moisture can end up directly beneath the
court. When the sun heats up the surface, the water is drawn upwards in a
vapor form. This creates hydrostatic pressure, and can break the bond
between the coating and the asphalt or concrete surface. The result is
multiple bubbles and blisters on the court surface. Concrete surfaces
should also have a 10 mil vapor barrier installed when the court is
built, to prevent this from happening. Unlike asphalt, concrete is very
dense and has a tendency to create higher levels of hydrostatic pressure.
This is why the problem happens more often on concrete courts.
Other than, and combined with poor drainage, surface blisters and bubbles
can also become an issue when too many coats of surfacing material are
applied. This can happen after many years of resurfacing cycles have been
performed. When a tennis court is resurfaced, there are anywhere from 3
to 10 coats of surfacing material applied, depending on whether it is a
hard court or a cushioned tennis court surface. The standard resurfacing
cycle should happen every 4 to 7 years. At some point, around the fourth
or fifth resurfacing, the owner may want to think about having the tennis
court contractor remove the existing coatings, back down to the pavement.
This helps to minimize the potential for bubbles or blisters, and
breathability issues. Also, tennis court coatings contain, or are job-
mixed with silica sand for filling voids and texturing the playing
surface. This creates non-slip safety, and sets the pace of the game.
Sand also breaks the surface tension of each coating layer and allows it
breathe better. Thus, it is recommended to specify sand into each coat of
In some rare cases, occasional bubbles may appear on a sport surface with
adequate drainage. This is most likely to happen during extreme weather
patterns that bring continuous rains and over burden drainage systems. If
the surface it not subjected to this problem long term, the bubbles
usually go down and disappear without further problems. The random bubble
can also be injected with acrylic latex to re-adhere the coating to the
pavement surface, if needed. A sport surfacing professional can take care
of this with minimal cost.
When having a sport court built, make sure the tennis court construction
company is familiar with the American Sports Builders Association
guidelines for proper sport construction. The best way to ensure this is
by contacting a manufacturer of tennis court resurfacing products and
asking them for qualified tennis court contractors in your area.