On The Surface
It is likely that many of us learned to play basketball and tennis on asphalt, with that sensation of feet baking in our shoes. With the inception of the first asphalt-paved road in 1868, and the first Converse shoe (circa 1915), the asphalt athletic surface has been a part of Americana for nearly 100 years. With this surface still prevalent in most park and recreation settings, and budget cutbacks still in effect, some basic maintenance practices, if followed, can extend its life and performance.
Numerous sports are played on asphalt; I have even heard of tackle football leagues playing on the surface. While it’s not my choice for Saturday morning exercise, it does show the versatility of its application. What makes it such a widely used product for outdoor basketball and tennis courts is not only price, but durability. Depending on the region of the country, asphalt’s basic components are rock, sand, tar and bitumen (some producers are now adding recycled products to the mix, like rubber and glass).
“The basic components of asphalt have not changed in the last 40 years. They do change according to the source of the crude oil from which they are refined, and with global shipments of oil these days, it is hard to say what source is going to which region. That’s why asphalt is specified according to its physical properties, not its chemical properties,” says David Newcomb of the National Asphalt Pavement Association.
Rock and sand give asphalt its strength, while the liquid elements of the tar and bitumen make it flexible. Over time, quality and durability diminish when the elements draw out moisture. However, with a good maintenance plan and regular resurfacing, an asphalt athletic court may last 20 years or more.
Problems Under Foot
The three main culprits of any asphalt problem are:
· Poor design
· Improper construction
· Natural aging.
It is worth noting that not all maintenance issues are due to age. More times than not, any major work on courts within the first three years is due to poor design or faulty construction. Bad materials also may be to blame. For example, if rust spots appear, it is often due to pyrites and iron deposits getting into the surface material during installation. Good record-keeping helps identify these problems.
With any outdoor material--whether wood chips on a playground or paint for a building--the elements play a direct role in its lifespan. Just about any climatic occurrence--from a hard freeze to the sun’s UV rays--affects how asphalt ages. For example, the sun quickly bleaches out the oils in unprotected asphalt, making the surface brittle and susceptible to cracking. Any water should be drained away from the court, as standing moisture breaks down acrylic surfaces over time. Additionally, seasonal movements from freezing and thawing cycles will move rocks in the base, causing surface breaks, bird baths and holes.
Devising A Plan
While today’s asphalt is better formulated, it still requires the same maintenance it did 40 years ago. Simply making sure that leaves and pine needles do not accumulate makes a major difference in cracks forming. Leaves and other plant material can hold moisture on the surface and over time will not only stain but break down the acrylic topcoat. (Excessive organic debris on asphalt athletic courts also causes slipping hazards.)
Another way to prolong the life of asphalt is to leave snow alone, and let it melt away in the spring. Snow shovels scratch away the topcoat and create divots in the asphalt, leading to larger problems the following year.
Signage and gate locks are further proactive measures to keep courts in playable condition. It is amazing how much damage can be caused from skateboards and other activities not meant for the surface. Vandalism, ranging from skateboards to spray paint to arson, also can be avoided through these measures.
When is it time to resurface a court? Various ranges are given by industry leaders, but 3 to 7 years are the average, and those are based largely on regional differences in climate, its direct effect on asphalt, exposure of asphalt to the elements and the surface’s use. There are several factors in ascertaining when it is time to resurface a court:
· Low areas/depressions (bird baths) that hold more than 1/16-inch of water
· Cracks interfering with game play and/or making conditions unsafe for users
· Surface paint that is faded, cracked and/or showing the sub-base
· Exposed tree roots or other surface upheavals that can create tripping hazards
· Discoloration and rust spots on the court surface
· Small bumps or “bubbles” on the surface that sound dead or hollow when bouncing a ball.
While all of these maintenance issues need to be addressed, cracks, upheavals and depressions are the most costly, and can lead to further problems if not taken care of promptly. Left unattended, they can destroy the sub-base.
There are various techniques available to restore and combat the effects of time and skateboards. Patching and filling can take care of minor cracks, divots and birdbaths. Many times, this work can be performed quickly with minimal downtime to court users. For larger cracks and depressions with depths up to a ¼ inch, a fabric overlay and resurfacing may be necessary. Courts that have numerous cracks, depressions and upheavals may need a completely new asphalt overlay, or may have to use some of the newer prefabricated overlay products. These techniques are expensive, but will add another 6 to 12 years to the court’s lifespan.
The best way to avoid or reduce repairs is with a quality maintenance program. Since weather, local sediment conditions and asphalt-mix vary from region to region, local contractors are able to evaluate these variables. Other components of a maintenance program include:
· Blowing or sweeping courts weekly
· Pressure-washing every 1 to 2 years to remove mildew
· Avoiding planting and keeping all larger trees at least 10 feet from the perimeter
· Repairing cracks as they appear (before they are beyond patching and before a freeze)
· Having courts professionally inspected every 2 years.
Keeping play surfaces safe for the public is fundamental to what we do. Retaining and prolonging their value is being a good steward of public and private funds. These two principles are at the core of every parks and recreation professional and, oddly, never illustrated better than by asphalt!
Steve Yeskulsky is a CPRP currently working in the parks and recreation industry in Sarasota, Fla. He can be reached via e-mail at firstname.lastname@example.org
Some Interesting Facts About Asphalt:
· Asphalt is America’s number-one recycled product--seven times more than plastic bottles, aluminum cans, newspapers and glass bottles combined!
· One of the oldest major sporting events to make use of asphalt is the Tour de France (1903 – present). In 1824, the French started paving their roads with asphalt blocks.
· Don’t stop running or walking during the summer, especially in Death Valley in California. It is an urban legend that shoes can melt on a hot day, and make the runner stick to the asphalt.