Factors to Consider Before Building
Assessing the Suitability of a Possible Tennis Court Site
Whether you choose post-tensioned concrete or another type of slab for your sport court, it's important to make sure your backyard space can accommodate the layout you have in mind. Here are the key factors to consider:
- Size. The overall size of a regulation tennis court for doubles play is 60 x 120 feet (per the International Tennis Federation). However, you must allow additional space around the court perimeter to give the contractor room to work and to permit the installation of drainage, landscaping, and fencing. Munson recommends leaving at least 12 feet between the court sidelines and the closest fixed obstructions, and 21 feet between the baselines and fixed obstructions. Where space is limited, you can downsize to a slightly smaller court. ITF recommends a minimum court size of 56 x 114 feet. An NBA/NCAA regulation full-size basketball court is 94 feet long and 50 feet wide. For backyards without enough acreage for a pro court, half courts can suffice for one-on-one games. (See this diagram of court dimensions from Half Court Sports.)
- Orientation. The time of day you plan to use the court and your geographic location will determine the best orientation for your court. If the court is to be used consistently throughout the day, ASBA recommends a north-south orientation as the best compromise between the extremes of early morning and late afternoon sun angles.
- Sloping and drainage. Proper slope of the subgrade is critical to allow water drainage away from the court. The ground should be reasonably level, preferably on the same plane or higher than adjacent land. (ASBA advocates a finished subgrade 4 to 6 inches above the surrounding ground.) If your site has a high water table, you may also need to install an underground drainage system. Options include French drains, properly graded gravel-filled trenches, geocomposites, and perforated drain lines surrounded with stone.
- Soil conditions. Even a well-constructed tennis court can fail if the subsurface it's built on is unstable. ASBA recommends hiring a qualified geotechnical engineer to perform a soil analysis, to identify such problems as expansive soils, high organic material content, and high groundwater conditions.
Post-Tensioned vs. Reinforced Concrete Tennis Courts
The two most common types of concrete slabs for outdoor play courts are reinforced concrete and post-tensioned concrete. However, post-tensioned concrete provides the best overall performance, according to the American Sports Builders Association, a national organization for builders and designers of tennis courts and other sports surfaces.
Post-tensioned concrete is reinforced with a grid of high-strength sheathed steel tendons, or cables. While the concrete is curing, the cables are tensioned in both directions and held permanently under stress by anchoring them in a perimeter beam. This squeezing actionkeeps the concrete in compression, improving its tensile (or bending) strength. The more the concrete is squeezed together, the less likely it is that shrinkage cracks will develop or open. (See a more complete description of post-tensioning from the Post-Tensioning Institute.)
Other benefits of post-tensioning: Contractors can build larger slabs using thinner concrete sections, and they don't have to install control joints, which can interfere with play. "In order to build a reinforced concrete court that has the same structural capabilities as a post-tensioned court, we would have to install so much steel and concrete that the reinforced court would actually cost more," says Kolkmann. "Also, a reinforced court needs control joints, usually at a spacing of 10 to 15 feet, including in the playing area. Eventually these joints may widen, as well as any cracks that appear."
Tennis Court Surfacing Options: Hard or soft?
Whether your preference is tennis, basketball, or another court sport, one of the most important factors influencing your game is the type of surface you play on. The characteristics of the court surface not only affect how fast the ball bounces, but also contribute to your comfort and ease of movement.
The International Tennis Federation has tested the typical ball speed for various court surfaces, and classifies them as slow, medium, or fast. Generally, a hard concrete surface-with no surfacing system applied-provides a fast speed of play. But if that's not your preference or you want a more resilient surface to reduce the impact on your joints, a proliferation of acrylic color coatings and cushioning systems are on the market that allow you to adapt the court surface to your style of play.
Acrylic color coatings are a combination of acrylic latex resins, pigments, and silica sand (for texture). They protect the court from the elements, enhance its appearance, and improve foot traction and consistency in ball bounce. They also make it possible to tailor the speed of play to your preferences by adjusting the amount, type, and size of sand used in the coating. For a standard concrete tennis court, the cost to install an acrylic color coating runs about $6,000, according to Kolkmann. To improve bonding of the coating, the concrete surface should have a broom finish (a lightly textured profile obtained by pushing a broom over freshly placed concrete).
Cushioned surfacing systems consist of one or more layers of cushioning material (usually rubber or plastic fillers) that result in a resilient surface with good traction and ball response. These systems are popular for both tennis and basketball courts because they allow for longer playing times by absorbing impact and reducing muscle fatigue. Modular tile systems are the newest cushioning option on the market and offer the benefits of easy snap-together installation, long service life, and minimal maintenance. These systems feature interlocking, 12-inch-square tiles made of high-impact polypropylene. The tiles rest slightly above the base surface to allow for better drainage and eliminate puddling. The downside of this cushioned comfort is the cost, which can run as high as high as $3 per square foot installed (or over $21,000 for a 60x120-foot tennis court).
ITF provides a list of many of the court surfacing products available (categorized by the rate of ball speed they provide) along with links to the websites of suppliers.
Choosing a Color Scheme for Your Tennis Court
Both color coatings and cushioned surfacing systems come in a gamut of colors, allowing you to branch out from the traditional green court surface and use nearly any color or combination of colors you choose on your backyard tennis court. While there is no "regulation" color scheme for tennis courts, some colors work better under certain conditions. In addition to aesthetics, ASBA recommends considering the following factors:
- Dark court surfaces provide better ball visibility because they contrast with yellow or white tennis balls and reduce sun glare.
- Two-tone color schemes more clearly define court boundaries. The color with the lowest reflectance (generally the darker color) should be used within the court boundaries.
- If you usually play during the day, lighter colors will absorb less sunlight and minimize a buildup in surface temperature.
- For night play, surfaces with low reflectance will require more lighting to illuminate them.