I have heard this question repeatedly over the past 35 years. I asked that same question when I first started repairing tennis courts in 1976. At an early age, I learned to patch tennis courts and apply rubber and color coatings. Repairing cracks was the most difficult. We would fill cracks with all types of fillers that were recommended by the same manufacturers that sold the color material. So often, we would hear of new fillers and try it without success. In addition, the installation of fabric membranes over the cracks were thought to be a sure fix. We soon learned that not only did it not work, but it often led to the membrane lifting and it became a tripping hazard which was dangerous and more costly to fix than just crack filling. We also came up with our own idea of heating the asphalt back up and filling with hot asphalt, tamping and applying color, but as soon as winter came along or a moderate change in temperature occurred, the crack would be back. Understanding the basic properties of asphalt paving is very important to understanding cracking on the court.
First, asphalt is the most common type of material used in building a hard-type tennis court surface. Private tennis courts and public tennis courts, like schools and public parks, use an asphalt base with a colored playing surface on top. There are many reasons why an asphalt tennis court will crack, the most common being “age.” Asphalt is, in simple terms, a slow-curing concrete. When new, asphalt will stay pliable and soft, when compared to poured concrete. When new, asphalt can withstand the severe winter cold because it can flex with the heave of a frost. As time passes, asphalt becomes harder as it cures. This process of hardening or curing happens over a period of 10 years or so, depending on the type of asphalt used. Once the asphalt is cured, it unfortunately becomes brittle. The oils that make the asphalt pliable begin to dry out, subsequently shrinking the area. Once brittle, a frost or change in temperature stresses the asphalt and a crack begins, small at first, but it grows in width and length as time goes on. In the winter, rain water fills inside the crack, freezes, then expands the crack wider resulting in the crack growing in length as well.
Another type of crack may develop from other means, such as settling or sinking areas, which is a clear sign of poor sub-base construction and poor compaction. Cracking, resulting from severe settling is typically caused by something buried under the tennis court surface which will essentially make the tennis court unusable. Rebuilding the tennis court is the best option with special attention given to the sunken area in this case.
Repairing a crack is really a perpetual maintenance issue. No one can really permanently repair a crack once it has developed. A contractor can fill a crack or cover a crack using a membrane, but the truth is, the crack will return, typically after the winter months. A better question to ask is: “Which method of repair will last the longest?”
Filling a crack is the most inexpensive way to repair or maintain a cracked court. It is also is the least effective and is considered a temporary fix used for cosmetic purposes lasting just one season. I must also mention that the color of the repairs will never match the old color due to sun fading and color batch differences. It still remains important to maintain these repairs in order to slow the deterioration of your court surface and make it at least playable.
One method, which is newer in design and is recognized as an option of the American Sports Builders Association is “Armor Crack” repair or “RiteWay” Crack systems. These systems are considered temporary repairs, but seem to last longer than the typical filling, sometimes up to five years. It is basically a series of membranes over a filled crack that is designed to bridge the crack. While the crack may return, it will not reflect through the surface. This process is more expensive to apply, but will relieve the owner of the anguish of seeing a crack every season, for a while anyway. It should be noted that this type of repair should be considered when it is time to apply a color system over the whole tennis court.
The decision of the type of repair is often a difficult one and depends largely on the owner’s expectations and budget. Unfortunately, there is always a point where these perpetual repairs will exceed the cost of rebuilding the tennis court base. As you can see, there are many reasons for cracking and I hope I have shed some light on this affliction which has plagued both private and public tennis court owners.
Kevin J. Healion, CTCB
<p>Kevin J. Healion, CTCB of Deer Park, N.Y.-based Century Tennis Inc. may be reached by phone at (631) 242-0220 or e-mail <a href="mailto:Kevin@CenturyTennis.com">Kevin@CenturyTennis.com</a>.</p>