Fix the Cracks
Taking care of cracked courts depends on why they cracked in the first place.
Admit it. Those cracks in your tennis court are getting completely out of hand. So what’s the best course of action? Quite simply, it depends on the reasons for the cracking, and the type of cracking.
According to Tennis Courts: A Construction and Maintenance Manual, published by the USTA and the American Sports Builders Association,
Cracking of asphalt is caused, at least in part, by the natural tendency of asphalt to shrink as it weathers and ages. In addition, asphalt loses its flexibility over time, making it more brittle.
Premature or extensive cracking may be caused by poor asphalt mix design, by poor site conditions including expansive soils or excessive organic matter in soils resulting in sub-base movement, or by poor construction including inadequate drainage.
Because asphalt is a material that shrinks and becomes more brittle as it ages, almost all courts made of asphalt will suffer from some type of cracking — either major or minor — at one time or another. Additionally, a court may show more than one type of cracking. A tennis court contractor is the best judge of the type of crack, the seriousness, and the cause. Once those factors have been identified, a treatment can be recommended.
“There are a lot of alternatives that can be considered, if appropriate,” says David Marsden of Boston Tennis Court Construction Co. of Hanover, Mass.
Treatments can be simple — requiring only an afternoon’s work — or they may be extremely complex — involving total reconstruction — or they may fall anywhere in between. A qualified court contractor can help you find the solution to your problem.
Crack repair is — as the term suggests — simply addressing the problem at hand by filling the crack. Contractors find that some cracks, such as those that are simply the result of freeze-thaw cycles and not of any serious underlying condition, can be treated with a crack-filling compound. (A very deep crack may require a full-depth repair, and the contractor should evaluate such a crack to see if it indicates an underlying problem with the court as a whole).
Most tennis court contractors do a fair amount of simple crack-filling, and as a result, are experienced in proper technique. If you elect to do the filling yourself, be sure to use a product recommended specifically for tennis courts; an unsuitable compound may not bond correctly or harden completely, or may soften in the summer heat, allowing players to track it all over the court. The book Tennis Courts: A Construction and Maintenance Manual describes the proper application of tennis court crack filler.
A newer method that may be used by tennis court contractors includes a special fabric that bridges the crack, preventing it from coming back in the same location, though the crack may recur at the boundary of the fabric or extend beyond the original repair.
“Crack filling is typically performed by cleaning the affected areas, grinding or sanding all heaving seams, and application with crack squeegees, caulking guns, or steel trowels, depending on which material is used,” says Franz Fasold of Ace Surfaces-North America of Altamonte Springs, Fla. “After curing, the areas are sanded again to blend them with the surrounding court levels. These methods are appropriate when no further movement, or only limited movement, is expected. These methods are limited by the extent of the base movements, especially if vertical shifts can be expected.”
If the court has proper slope and drainage, and if cracking is not the result of serious structural problems, the contractor also may recommend resurfacing, defined as putting a new surface on the court. There are various ways of doing this. The simplest is by filling the cracks and then putting a new acrylic coating on top of the court in order to create a smooth, unblemished surface. This option maintains the original type of surface as well as the original feel and playability of the court.
When contemplating resurfacing, however, an owner might want a different type of surface, perhaps something softer and with different playing characteristics. In this case, a contractor might recommend that once all cracks have been filled and the court recoated, a new surface be installed over the existing court.
One popular option is a system of sand-filled turf. This is a system composed of a densely-woven carpet filled with compacted silica sand. A court owner may see this as a reasonable solution, particularly if the site is not easily reachable by heavy construction equipment, or if the owner would like to see the project completed with a minimum of disruption to adjacent courts or facilities.
A similar option is to cover the court with interlocking modular tiles. Fred Jones of Utica, N.Y.-based Mateflex says that modular surfaces, produced with a raised-grid design, “allow for installation over imperfect bases, while also allowing rainwater to pass directly through the system and drain off underneath.” The resulting surface is softer than a traditional hard court, but is easy to take care of, requiring only occasional cleaning and allowing for easy repair and replacement, should tiles be damaged.
Of course, new surfaces are only as good as the underlying base. Jones notes that resurfacing with one of these systems may not eliminate the need to repair base problems, depending on their severity. Problems such as birdbaths, or depressions in the court, for example, must be addressed prior to putting down tiles, since the tiles will bridge the court’s low spots, affecting ball bounce in those areas.
There are other options for resurfacing. These might include urethane rubber roll goods which can be covered with an acrylic surface, as well as various other products. A tennis court contractor can explain the playing characteristics (slide, bounce, speed, etc.) of each surface and help the owner reach an informed decision, should the resurfacing route be taken.
Often, a court can have severe reflection cracking (indicative of underlying problems), but still have appropriate slope and drainage. In these cases, contractors often suggest that repair be made using an overlay, or slip-sheet overlay. According to Marsden, a slip-sheet overlay is “a thin layer of stone or stone dust placed directly over an old court surface prior to a new asphalt surface being laid. The stone acts as a slip sheet and absorbs any movement from the old, cracked court below before it reflects up to the new surface.”
The slip sheet is used to separate existing asphalt pavement from newly installed pavement to prevent cracks from recurring. Once the slip-sheet overlay is securely in place, it can be covered either with new asphalt (which is then covered with acrylic coating), or with concrete. It is important to note, however, that this method will raise the elevation of the court.
In a post-tensioned concrete overlay, an entirely new concrete slab is installed over the problem court. Because the concrete is reinforced and strengthened with high-tension steel cables, the concrete has higher tensile strength than conventional concrete slabs or asphalt, and may be more resistant to most conditions that may have caused the underlying court to crack in the first place. According to Steve Wright of Trans Texas Tennis Inc. of Olathe, Kan., “It is an ideal system for overlaying asphalt and concrete courts that have structural cracks, poor drainage, or improper slope.”
The post-tensioned overlay system eliminates the need to remove the existing pavement, which saves in demolition, hauling, and disposal costs. The method is appropriate in certain circumstances, but will not work for every situation, such as in situations where access for large construction equipment (bulldozers, dump trucks, etc.) is an obstacle, or where underlying soil conditions are questionable because of the presence of fault lines or excessive heaving or settlement. In addition, it is relatively expensive.
If a court shows signs of severe heaving or depressions, with major amounts of cracking and/or improper slope and drainage, a contractor may recommend a total court reconstruction. According to Marsden, methods include excavation followed by reconstruction of the court, and pulverization followed by reconstruction. In the first option, excavation, the old court material is removed and disposed of before putting down new material. In the second option, the asphalt is pulverized with special equipment and then used to form a new base.
“There are cost differences in excavation versus pulverizing,” Marsden notes, “and the comparative cost of either method will be determined by the size and location of the project. With a smaller project — one or two courts — it is usually cheaper to excavate unless the haul to the asphalt disposal site is long and costly. In the case of three or more courts, it is usually cheaper to pulverize. The reason is the high overhead cost of the pulverizing equipment. It isn’t much more money to pulverize six courts than one court. The daily cost of the equipment is not proportional to the area pulverized. But many factors need to be considered before choosing one method over another.”
In replacing an asphalt surface, a contractor may recommend the installation of control joints to help delay or deter cracking. By saw-cutting the asphalt under the net and between courts in a multi-court project, the contractor can actually take advantage of the asphalt’s natural tendency to move and shrink according to temperature. The cuts are then filled with a special type of sealant prior to the court being coated with acrylic color. Relief of stress in those areas makes the court less likely to crack elsewhere over its surface.
Some court owners may decide to explore the option of converting their hard court to one with a fast-dry surface. Since this is technically something that can be done following excavation, it is a form of reconstruction; however, it is more complex, involving the installation of an entirely new type of court, and the possibility of installing ancillary equipment, such as an irrigation system. A court contractor can make recommendations concerning the best method of conversion, but those interested can always learn about the process by checking the ASBA’s Construction Guideline on Conversion of Hard Surface Courts to Fast Dry Tennis Courts.
The Guideline provides four different methods of surface replacement including two overlay methods as well as pulverization and excavation; a qualified court contractor can assess the situation and make a recommendation regarding the best choice for a given facility. The contractor should also ascertain that court owners know that although the soft court will not suffer the same type of cracking problems, it will have specific maintenance needs that should be taken into consideration.
Doing battle with cracking courts means arming yourself with information about your options. A lot of factors come into play, some on the part of the contractor, some on the part of the court and its owner.
“Indicators for successful reconstruction methods are a combination of factors,” says Fasold, “including a history of similar projects, the history of the court builder, use of design and engineering experts who are familiar with sports facility specifics and use of local experts.” Most important, he notes, is the ability of the contractor to “put the search for a successful solution over the opportunity for a quick sale.”
Factors relating to the court include the site, the location, the budget, the wishes of the owner, the needs of the players, and more. Knowing your parameters when you meet with your court contractor will make it easier to arrive at the right decision for you and your facility.
In terms of crack repair, there are a lot of options and very few absolutes. What works in one installation may not work in another that is a mile — or even a block — away. Cracking may be minor but irritating, or it may be severe enough to cause injury to an unsuspecting player. It may be merely an aesthetic concern or it can signify underlying instability in the court. The only common denominator is the qualified tennis court contractor who can help diagnose the problem and assist the owner or manager in finding the best long-term solution. It is important to note that more often than not, cracks can be expected to recur unless the underlying cause of the cracking is repaired or the most extensive (and expensive) repair methods are employed.
“In the end,” says Fasold, “it is our belief that the court will only be as good as the base it is applied on. It is important to put great emphasis in the decision-making process of how to correct the issues at hand up front.”
The ASBA identifies various types of cracking, including:
- Alligatoring: A readily identified pattern of interconnected cracks that vary from a faint surface pattern to full depth cracks and loose particles of the surfacing material.
- Raveling or Spalling: The progressive loss of material in the surface of the asphalt or concrete slab, usually caused by weathering or traffic abrasion on courts with no surface treatment.
- Reflection Cracks: Which occur in asphalt, asphalt emulsion, or surface overlays, and which reflect a crack pattern in the pavement structure underneath.
- Shrinkage Cracks: A random pattern of interconnected cracks, usually forming irregular angles and sharp corners.
- Structural Cracks: Usually due to failure of the subbase or improper mix design of the asphalt.
- Upheavals and Depressions: Caused by movements of the sub-base.
- Hair-Line Cracks: Usually prevalent over large areas, even entire courts, and caused by a variety of things.
See all articles by Mary Helen Sprecher
About the Author
Mary Helen Sprecher is the managing editor of Sports Destinations Management Magazine, a niche business-to-business publication for planners of sports travel events, in addition to being an RSI Contributing Editor. She is the technical writer for the American Sports Builders Association and works as a newspaper reporter in Baltimore City.