| 1.0 | Introduction | ||
| Asphalt-bound tennis surfaces, by far the most prevalent type of construction, require resurfacing periodically. This resurfacing can range from a simple new color finish system to full asphalt overlay(s). It is recommended that the owner consult a qualified tennis court contractor, professional engineer or architect. Prior to installation of the new surface, special attention should be given to defects in the existing surface resulting from improper original construction or from other causes. Some of these defects and their causes are listed below. | |||
| A. | Drainage – Subsurface Improper perimeter drainage can cause excessive subsoil expansion that results in greater damage to the surface from freeze/thaw action and can, in turn, cause the surface to heave and create “birdbaths.” Also, this condition can cause loss of color and permit dirt and silt to wash onto the surface. By lowering the elevation of perimeter drainage swales, and consequently lowering the water table, this condition is improved or corrected. If wet conditions are encountered, a subsurface perimeter drainage system such as a perforated pipe in stone aggregate is advisable. | ||
| B. | Drainage – Surface Puddling or “birdbaths” can be corrected or greatly improved by patching or overlay but only if the original surface was installed to essentially the correct recommended slope of .833% to 1% on a true plane from side to side, end to end or corner to corner. (Side to side is recommended if site conditions allow.) If the existing asphalt has lost its life and a complete asphalt overlay is dictated, depressed areas of 3/8” or less are generally corrected by the overlay. Depressed areas in excess of 3/8” should be patched prior to the overlay. On the other hand, if the existing surface is essentially sound and relatively free of expansive cracking, simple filling and leveling of depressed areas would correct or greatly improve major “birdbaths.” | ||
| C. | Expansive Cracking Expansive cracking is a fairly common condition encountered in older tennis surfaces and is directly related to the expansive nature of the subsoil, degree of oxidation, atmospheric temperature variations, improper original construction and/or other causes including substrate movement or other acts of nature.The use of various geotextile mats or membranes in conjunction with a hot plant mix asphalt overlay has been the successful method employed to bridge expansive cracking, but it should be stressed that this method is NOT consistently successful. Specifically, it should be stressed that NO method employed to bridge expansive cracking is consistently successful short of removing the existing surface and correcting the cause of the problem before installing a new one. | ||
| 2.0 | Range of Resurfacing Procedures | ||
| A. | Color Finish System The application of a new multiple coat acrylic color finish system in accordance with manufacturer’s directions is dictated over a surface essentially sound but showing loss of color and texture. Prior to application of the color system, “birdbaths” should be corrected by patching with an appropriate patching product, and possibly finished with one or more applications of acrylic resurfacer. This acrylic resurfacer is generally applied by squeegee and is intended to blend the patching with surrounding areas to a uniform texture. | ||
| B. | Complete Overlay The application of a complete in-depth hot mix overlay is dictated over surfaces that are badly oxidized or aged. In addition, an in-depth overlay is recommended to improve poor planarity and/or surface drainage. A poorly constructed base or drastic variations from a true plane are factors that should be considered in determining the depth of the overlay. | ||
| C. | Methods of Repair | ||
| 1. | Hot Asphalt Overlay Method Prior to the 1″ overlay, a leveling course of dense asphalt may be necessary for correcting the planarity of the court surface. This is a method of placing 1” (compacted) or more of hot plant mix asphalt over an existing asphalt tennis court. The overlay system can be successfully done over a court that has minor faults; however, it may not prevent the reappearance of cracks from the slab beneath. To improve adhesion of the overlay to the existing slab or levelling course, a tack coat or a bond coat of emulsified asphalt should be used. | ||
| 2. | Full Depth Repair In any patching, the area requiring a patch should be cleared of all loose material, dust and dirt. Any defective materials should be removed to the full depth of the defect. If the defect is in the asphaltic courses but is caused by a failure of the underlying base course, the defective base material should also be removed. If it is necessary to replace base course material, it should be ascertained that the subgrade condition is as it should be prior to replacing any base course. If the subgrade requires attention, it should be brought up to specification requirements prior to patching any of the asphaltic courses which the base course supports.A tack coat, in accordance with the manufacturer’s specification, must be applied to the bottom and sides of the patch, and allowed to cure thoroughly. If the defective material is old asphalt pavement, and the depth of the defective material and the subsequent repair will exceed 3/8”, hot plant mix asphalt may be used. The compacted lift should be brought to the elevation of the surrounding sound surface. | ||
| 3. | Geotextile Membranes | ||
| a. | Subgrade Use In major repairs, it may be necessary to spread the load of the tennis court more evenly over a larger area of the subbase. By using such materials as geotextile membranes beneath the base course of the stone or aggregate, the load will be spread, reducing the possibility of settlement or reflection of the subgrade problem. This method can be used to localize the reconstruction or possibly to avoid major reconstruction. | ||
| b. | In Combination with Asphalt Overlay Use of geotextile membranes in overlays has become popular in road resurfacing. This method can reduce the need for reconstruction and minimize the cost of repairs. Consult geotextile manufacturers for appropriate construction methods. | ||
| 4. | Stone Slip-Sheet This construction consists of a layer of crushed stone or aggregate overlaid with hot mix asphalt. The thickness of the aggregate layer will vary depending on the site condition. Once fine graded, the court is overlaid with hot mix asphalt, in two lifts, a 2” compacted lift of base asphalt and a 1” compacted lift of surface asphalt. Under certain conditions, one compacted lift of surface asphalt may be used over stone base.This method can be used to repair tennis courts with a crown at the net without major reconstruction. It is also used to increase pitch on a level court without drainage and to overlay major surface failures and minimize the reflection of the problem. | ||
| 5. | Asphalt Surface Course The final course of the asphalt should consist of a minimum compacted 1” thick mixture of asphalt and aggregate not to exceed 3/8″ in size.The proper type of asphalt used for the surface course will vary from state to state if using the standard norm of the Department of Transportation (DOT) or State Highway Department standards. Thickness: Not less than 1 1/2″ prior to compaction. Liquid Asphalt or Bitumen: Not less than 5.5% by weight. Asphalt Penetration or Type: 85-100 penetration. Aggregate Type: Crushed stone, gravel, shale, limestone, etc. No foreign materials; i.e., pyrite, clay, ferrous compounds, dirt or organic material should be acceptable. Voids Content: Minimum as specified by the Department of Transportation or State Highway Department, but in no case should voids content exceed 7%. Spreading and Compacting: Hot plant mix should be spread and compacted by methods and in a manner that produces uniform density and thickness. Installation Equipment: Self-propelled paving machine with heated vibratory screed. Rolling: Not less than 3 to 5 ton tandem steel wheel finish roller. Finish Rolling: Not less than 1 ton tandem steel wheel finish roller. Flood Check: Any ponding or “birdbaths” remaining after 1 hour at 70 degrees F in sunlight which cover a five cent piece (American coin) should be filled prior to any further applications. The finished surface should slope not less than 0.83% (1:120) but no more than 1% (1:100). Each court must slope on a true plane, preferably from side to side (but from end to end or from corner to corner are also acceptable), or in the shortest direction for good drainage and water runoff. The court should never be sloped from the net line to the baseline, from the baseline to the net line, from the sides to the centerline or from the centerline to the sides. The finished surface of the court should not vary more than 1/8″ in 10″ when measured in any direction. | ||
| 6. | Post-Tension Concrete Slab This method can reduce the need to remove or reconstruct the tennis court, serving as a feasible means for correction when site access is limited or conditions are confining. It is important to consult with a qualified contractor, architect or engineer to determine the feasibility of this method. | ||
| 7. | Pre-manufactured and Modular Surface Systems This method can be considered if you find no evidence of base or subbase failure or vertical deflection. These systems serve to retrofit existing courts without major disruption to site conditions such as fencing, net posts, landscape and drainage. | ||
| 8. | Surface Repair | ||
| a. | Birdbaths Any areas holding enough water to cover a five cent piece (American coin) after draining a minimum of one hour at a minimum of 70 degrees Fahrenheit in sunlight, should be outlined with chalk and the water swept out. After the area is cleaned and dried, a tack coat of suitable material must be applied to the entire area within the chalk-line.Estimate the required quantity of the thin patching mixture to fill such “birdbaths.” Apply it to the area, and strike it off with a straight-edge the length of which is in excess of the dimensions of the “birdbath.” A proper strike-off will level such a birdbath to the same elevation as the surrounding surface. After the leveling operation, the patch should be allowed to cure properly. There are various emulsified asphalt and acrylic materials to accomplish the above patching methods. The patch material should be compatible with the surfacing material and should be used in accordance with the surfacing manufacturer’s directions. | ||
| b. | Fiberglass Membrane Systems This method is designed to restore the surface of courts with extensive hairline surface cracking. There are several products on the market and they should used as per manufacturer’s specifications. These treatments are not intended to restore badly cracked or broken surfaces, nor to permanently seal cracks subject to base movement. | ||
| c. | Color Finish Course Re-Coating Re-coating of the color finish course should proceed after all repairs have been completed and all appurtenances such as net post sleeves and anchors, fences, and gates have been checked and all maintenance has been performed where needed. On tennis courts not requiring repairs, only re-coating, the following procedures will be the guide:Over the suitably prepared surface of the tennis court, apply two or more coats of material in accordance with the coating manufacturer’s recommendations. Resurfacing materials are suitable as a base coat, but the final applications should be acrylic color coatings made for tennis courts. When recoating existing acrylic surfaces, only compatible acrylic bound materials are acceptable. It should be noted that excessive layers of color finish material may cause or magnify problems with the asphalt. Consult a qualified contractor, engineer, or architect to best evaluate your situation. | ||
Note: Refer to Guidelines for:
1.A. General Conditions for Construction
2.A. Tennis Court Orientation
2.B. Tennis Court Dimensions and Related Measurements
2.I. Hot Mix Asphalt Tennis Courts
2.O. Acrylic Color Finish Systems for Tennis Courts
ASTM specifications are available from
American Society of Testing Materials (ASTM)
100 Barr Harbor Drive
West Conshohocken, PA 19428
610-832-950
NOTICE: These Construction Guidelines are for use by architects, engineers, contractors, tennis court and running track owners. Parties not experienced in tennis court or running track construction are advised to consult a qualified contractor, consultant and/or design professional. Experienced contractors, consultants and/or design professionals can be identified through the U. S. Tennis Court and Track Builders Association. Due to changing construction technology and techniques, only the most recent version of these Guidelines should be used. Variances in climate, soil conditions, topography and other factors may make these Guidelines unsuitable for certain projects.
Copyright © 1998 by U.S. Tennis Court and Track Builders Association. All Rights Reserved.