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Concrete Sport Surfaces

Shot Blasting Concrete Sport Surfaces | Tennis – Pickleball – Basketball

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A shot blaster is a machine that is commonly used to create a texture, or profile, on concrete.  There are various sizes of “shot” that can be used in these machines.  Shot blasters propel the shot particles, or media, onto the surface and suck it back in to create texture.  Our coating systems, and many other coatings, need some texture on the surface to create a good physical bond.  We recommend concrete being finished with a medium-broom finish, as opposed to a smooth trowel finish.  Sometimes this doesn’t happen, so the best way to get a good texture profile is to shot blast the smooth surface.

Shot Blasted Area Concrete
Shot Blasted Concrete Area

This is also a good way to “open up” the concrete and remove potential curing compounds or surface residue that can cause bonding issues.

Shot Blast Profile For Tennis, Pickleball, and Basketball Court Surfaces

The shot blast industry has a shot blast profile chart that lists various levels of texture, created by the shot blast.  It also ties each of the texture levels to a recommended thickness of coating system.  In other words, the thicker the coating system build, the more texture needed on the surface.  Our sport coating systems, based on the average thickness and factoring in multiple resurfacings over time, work well over a shot blast profile of CSP3 or CSP4.  Don’t worry, if the shot blaster profile turns out with a little too much, Acrylic Resurfacer will fill in and hide the voids.   This may require extra coats, but better to have more than less for good physical adhesion.

Shot Blast Profiles For Sport Surfaces & Courts

Where To Find Shot Blasters For Court Surfaces

Shot blasters come in various sizes and are commonly rented at equipment rental stores.  Many times, flooring contractors that apply epoxy and polyurethane (industrial coatings) own these machines.  It may be best to hire and/or subcontract this work to contractors with experience to get past the learning curve.  They usually have larger ride-on models that get it done quickly, too.

Steel Shot Abrasives For Shot Blaster
Shot Blaster on Concrete Court
Shot Blasting Concrete Court

Applying Sport Coatings on Concrete Surfaces | Specifications

To see the SportMaster engineering specification, which includes the basic steps of the process,  click on the link below.  This will open a .pdf version of the document.

Applying Sport Surfaces On Concrete

Visit our full page for more information on proper preparation of concrete sport surfaces.

Tennis Court Surfaces

What causes bubbles or blisters on a tennis court surface?

Bubbles and blisters on a tennis court surface, or other coated sport surface, are fairly common.  This is usually a result of improper tennis court construction or malfunction of the drainage system. When sub-surface water becomes excessive and is not properly drained away from the court, it can breathe through the slab in a vapor form and create hydrostatic pressure under the coatings.  This pressure builds more in weaker surface areas and creates a blister or bubble.  When the blister is raised, water vapor stretches the coating film and slowly breathes through to escape.  After most of the water pushes through, blisters usually lay back down and disappear until the next rain or precipitation event.  It’s important to note that excessive watering (sprinklers) around the court edge can also lead to blistering problems.  That being said, it’s very important to minimize accumulation of water beneath the court slab.

bubbles blisters pickleball court surface
Bubbles or Blisters on Court Surface

How Do I Get Rid of Bubbles and Blisters on a Tennis Court Surface?

In order to take care of the bubbles and blisters, long term, you will need to do some investigating.  Start by making sure any and all drains around the tennis court are free of debris or anything that would prevent proper flow of drainage water.  You may want to enlist the help of an architect or excavation professional in order to evaluate the current drainage system and see if it was installed properly, or at all.  If the court substrate is concrete, you must ensure the following:

  • Was a vapor barrier installed beneath the court when poured?
  • Are there perimeter drains that can take the water away from the court when it runs off after a rain? (Important that water is intercepted on all side of the slab, to prevent water beneath the court)
  • Was the concrete allowed to cure for 28 days, prior to coating?
  • Was the concrete surface acid etched to neutralize the alkalinity and balance the PH?
  • Were any curing compounds used on the concrete?
Court Surface Edge Drain
Surface-type drain – good for the low court edge

 

 

 

 

 

The American Sports Builders Association (ASBA) maintains construction guidelines for asphalt and concrete tennis court and sport surfaces.  Ensure that the construction of the court meets their guidelines and find out from the tennis court builder if they followed the ASBA recommendations.  This may help you figure out why the blisters are occurring.  If you are still not sure what to do, feel free to fill out the contact form on this page and we can put you in touch with a SportMaster recommended, tennis court builder.  They can perform a free site visit with you and provide feedback and estimates for repair, resurfacing, or re-construction. You can view our Engineering Specification for Athletic and Recreational Surfacing on our SportMaster site.

Tennis Court Blisters
Tennis Court Blisters