Tennis Industry magazine


New Solutions for surface compaction

Two machines from the golf industry are helping to rehabilitate, and rehydrate, compacted clay courts.

By Ed MonteCalvo

Clay tennis courts are in increasingly heavy demand by clubs and avid players alike because of the health benefits they provide, including a cooler, softer surface that is easy on the joints. To best maximize revenue with a clay-court facility, you need to keep your clay courts in excellent condition. The last thing you want to do is give your players and members an excuse to go elsewhere.

Surface compaction
Surface compaction
Surface compaction
Surface compaction
surface compaction

If clay courts aren’t maintained properly, one condition that can occur in some areas is “surface compaction,” which is when the top half-inch or so of the clay becomes compacted and hard. The characteristics of the court change when the surface becomes compacted. For players, it will often feel like they’re playing on a hard court.

Outdoor courts in the Northeast are not particularly susceptible to surface compaction, in most instances due to the cycle of freezing and thawing. This condition however, can occur in areas where there are longer playing seasons, with an increased demand for courts, which leads to less down time for watering and rolling. Indoor tennis courts are one example where facility managers need to be aware of surface compaction. Other areas of concern would be in the ever-growing Sunbelt regions from Georgia to California, below the 35th parallel.

Failing to scarify the surface regularly and also rolling the surface when it’s too wet can cause surface compaction, whether indoors or out, in warm climates or cold. In afflicted courts, the condition shows as a distinct layer of compacted material, starting as a thin layer at the top and working downward. The particles of surfacing material are pressed closer together in a smaller space, the bulk density increases, porosity decreases, and the water infiltration and water retention rates decrease. Essentially, with surface compaction there are no “void spaces,” so water cannot work its way up and down through the surface material. When it rains, a compacted court may stay wet longer because of a lack of “porosity.”

Staying ahead of surface compaction is not difficult. Scarifying the surface regularly, daily if possible, will keep the surface agitated and generate sliding material. “There’s not a lot you can do to permanently hurt a clay court or fast-dry court,” says Fred Manchester, a CTCB with Tennico of Columbia in South Carolina. “The damage will occur if you’re not aggressive enough.”

Back in the day, a compacted court had to be completely dug up. To help maintain courts, hand tools are good for a certain amount of depth, but if you have courts that are heavily compacted, you need something with more firepower. Thankfully, there are a couple of pieces of equipment, both adapted from the golf-course maintenance industry, that do an excellent job rehabilitating clay courts that suffer from surface compaction. They do so in a fraction of the time and expense it would take to dig up the courts and with a minimum of down time for players.

Rehydrating Courts

To punch through compacted soil on a golf course or, in this case, to punch through clay material so that water can move through it, the Toro HydroJet (below) can shoot 10 millisecond jets of water at 5,000 psi. The water comes out of the machine at 600 mph, the diameter of pencil lead. The HydroJet drills these tiny holes into the surface every 3.5 inches (or 15 to 20 holes per square foot).

Instead of keeping a court out of service for days, with a machine like the HydroJet, which basically shoots holes through a surface that is almost as hard as concrete, it takes one man-hour per court. And you can go over the court surface multiple times, depending on how extensive the compaction is.

The HydroJet not only makes vertical holes, but also causes lateral fracturing, further loosening the compacted area. After using the machine, the surface needs to be lightly scarified, then a coarse blend of top dressing is applied and broomed into the holes, so that they won’t re-compact. Last, a regular top dressing is brushed in and the surface is watered normally. The holes will have disappeared, the surface will be rehydrated, and the courts will look and play nearly brand-new.

Another piece of equipment being pressed into service on compacted clay courts is the Dryject machine (above) provided by Dryject, a New Jersey-based national franchise servicing the golf-course industry.

Bill Shaughnessy, a CTCB with The Racquet Shop Inc. of Colts Neck, N.J., says he used the Dryject machine at an indoor facility in New Jersey with excellent results. “The courts were so compacted, because the facility just kept adding material to it, that they became extremely slick and the lines got buried,” he says. “We were able to turn it back into granular material.”

Dryject fills the holes at the same time it injects and makes the holes. The machine injects a coarser blend of material into the holes, which helps water to move up and down. After using the Dryject machine, the courts were scarified and renovated.

While it’s reassuring for clay-court managers to know there are remedies out there for fixing surface-compacted courts, the idea is to not let it get this far to begin with. Have a clay-court specialist take a look at your courts to see what state they are in, then adjust your maintenance schedule as needed to make sure the courts stay playable, all the time. A successful club can keep their members happy with this routine procedure.

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About the Author

Ed MonteCalvo is a technical representative for Lee Tennis and can be reached at or 800-327-8379. He recently spoke about surface compaction at the annual meeting of the American Sports Builders Association.



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