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(subsurface irrigated Har-Tru courts – HydroCourts, Hydro Grids, CalCap)

Daily Maintenance

• Groom the surface using a court rake to smooth out and level any accumulation of material and clean the tapes using a line broom. It is important to agitate subsurface irrigated courts on a regular basis to inhibit the growth of algae and fungus

As Needed Maintenance


Subsurface irrigated Har-Tru courts have a tendency to become very firm over time due to the high moisture content of the courts. The following activities should be undertaken on a regular basis to improve playability:

• Use a court rake or similar maintenance product to agitate the playing area daily
• Use a tow scarifier around the perimeter of the court to break up "hardpan", particularly on the low side of the court


A subsurface irrigated Har-Tru court will develop depressions or low areas over time in certain high play areas (baselines, service boxes). These depressions/low areas will be evident because water will stand in these areas after a heavy rain. Running a string line over the court will also highlight low areas. These low areas will need to be patched. To patch a low area, follow these steps:

  • Scarify the low area with a lute or other scarifying equipment to rough up the surface - this helps the new HydroBlend material to bind and adhere to the existing court
  • Spread new HydroBlend material into the low area
  • Level HydroBlend material with a straight-edge (ladder or flat side of a lute)
  • Hand water and roll the low area
  • You may need to repeat the process if the low area is particularly deep


Subsurface irrigated Har-Tru courts rarely need to be rolled, primarily because the high moisture content keeps them firm and compact. However, subsurface irrigated courts should be rolled under the following circumstances

  • After a top-dressing
  • Lines should be rolled if they start to get high

Top Dressing

Sprinkler irrigated Har-Tru courts will lose material over time due to the effects of watering, wind, rain, and play. Sprinkler irrigated Har-Tru courts in most regions of the country will lose 2-3 tons per year (50-75, 80 lb. bags). Sprinkler irrigated courts in Florida lose 4-5 tons per year (100-125, 80 lb. bags) due to more rain and year round play. In order to properly maintain a Har-Tru court, they must be top dressed on an annual basis. To top dress, follow these steps:

  • Before top dressing, be sure the court is completely dry
  • Scarify the entire court surface using a tow scarifier, Court Devil, or lute
  • Patch low areas (see above)
  • Apply court surfacing material using a spreader ( link to spreader page on www.10-s.com )
  • Level the material using a straight edge, usually a ladder
  • Hand water and roll the court

Top Dressing Tips

•  You can either top dress using a small amount of material (8 bags per court) on a monthly basis or top dress using a large amount of material (50-75 bags per court) once per year

•  If you are going to add more than 25, 80 lb. bags at one time, you may also need to remove and replace the line tapes, as more than 25, 80 lb. bags may bury the lines

Long-Term Maintenance and Upkeep

Har-Tru courts require 1" of Har-Tru surface material for optimum playability, court stability and moisture retention. For this reason, all new sprinkler-irrigated Har-Tru courts are built with +/- 40 tons (1,000, 80 lb. bags) of Har-Tru surfacing material. Each new Har-Tru court is also built with a 1" in 30' slope to ensure adequate rainwater drainage. This means that a new single court will slope 2" if it is sloped from side-to-side or 4" if it is sloped end-to-end.

Sprinkler irrigation, rain, wind and play will cause Har-Tru material to regularly wash off the court and to migrate (or "shift") from the high side of the court to the low side of the court. Over time, your Har-Tru court will lose the ideal surface depth of 1" and the slope of the court will begin to "flatten out". These changes will cause the court to retain less moisture, shift under rolling and play, and drain poorly, resulting in less than optimum (possibly even dangerous) playing conditions. Consequently, sprinkler-irrigated Har-Tru courts should receive a "laser-tapered" resurfacing every 4-5 years.

In a "laser-tapered" resurfacing, laser guided grading equipment is used to remove excess material at the low end of the court and add new material at the high end of the court to restore the proper court slope. Fast-Dry Courts, Inc. was one of the first companies in the United States to utilize this revolutionary technique to restore Har-Tru courts to a like-new condition.