Question: How long should asphalt cure before applying sport surfaces?
Answer: New asphalt should cure a minimum of 14 to 30 days, prior to application of a sport surfacing system.
Asphalt Curing & Sport Surfacing Systems
Asphalt consists of rock, generally limestone, and liquid asphalt. The liquid asphalt, also referred to as asphalt cement or asphalt binder, is the “glue” that holds the rock together and enables the paving layers to bind to the prepared base.
When asphalt is newly paved in place, it exudes some excess asphaltic oils during the initial curing of the slab. It’s important to let some of the oils cure out, before application of any coatings, sealants, and sport surfaces.
Risks of Inadequate Asphalt Curing Before Surfacing
If the asphalt is too rich with asphalt binder and hasn’t had the opportunity to cure, or release the initial gush of asphalt oils, it can potentially lead to:
Lack of proper coating system adhesion (which may result in peeling and other paint and coating failures)
Staining, yellowing, and discoloration of the sport surfaces and coatings.
What are prime conditions for asphalt curing?
Hot & sunny conditions will help to pull the rich asphalt binder up to the surface. Once the excess oils are pulled to the surface, it is also important to have rainfall. This helps to rinse some of the oils away and “unplug” the pavement voids. The combination of sun to draw the oils to the surface and water to rinse them away, allows for continuous prime curing conditions.
If the conditions are good, the asphalt can be ready to coat in a minimum of 14 days. The safer option is to wait 30 days, if time allows. If conditions are warm and sunny after paving, but the area experiences a drought, rinsing of the surface by manual methods can help to keep the curing process in motion. Indoor asphalt curing can take longer than 30 days, to ensure sufficient release of oils.
Since there are variables, and no actual testing processes to guarantee initial curing, it is best to allow proper time for adequate curing. Sport coating manufacturers & experienced sport surfacing contractors are the best source for recommendations, when it comes to proper application timing. Rushing to resurface your tennis, pickleball, or basketball court before the asphalt is ready can lead to expensive problems now or down the road.
Athletic & recreational courts (tennis, pickleball, basketball, etc.) are built from either asphalt or concrete pavement. The type of substrate used is normally determined by region, cost, preference, availability or site access.
Each substrate (asphalt or concrete) has its own set of requirements, when it comes to application of acrylic sport surfaces. This bulletin will discuss how to properly prepare concrete for sport surfacing athletic courts.
Concrete Court Construction
When it comes to proper concrete court construction, there is a long “to-do” list. As with anything, there is always a good, better, best list of what to do and why it is important. If you are considering having a recreational court built, we recommend getting a copy of the American Sports Builders Association’s construction & maintenance manual. They publish and sell these for tennis or pickleball, which is also useful for basketball and other sports. That being said, we will reference a short list of the most important factors, prior to application of acrylic surfaces.
Install Vapor Barrier
Prior to pouring the concrete slab, a vapor barrier should be installed to prevent upward migration of ground moisture. This normally consists of two sheets of 6 mil polyethylene plastic sheeting, laid in opposite directions. Make sure it is overlapped and taped at the joints. The vapor barrier is on top of the stone base and under the concrete slab.
Ensure Adequate Perimeter Drainage & Slope
Another very important factor, when trying to minimize water accumulation under the concrete slab, is good perimeter drainage. If one or both of these items are lacking (vapor barrier & perimeter drainage), your court surface could be in danger of bubbles or blisters in the coating. In most cases, this will lead to peeling of coatings and bare spots down to the concrete. Court surfaces should be sloped at 1% in one direction, which is 1″ fall in every 10 feet. This helps to keep water flowing off the court and ensures fast drying surfaces and less standing water.
Medium-broom Finish or Similar Surface Texture
When pouring and finishing the concrete, make sure that the concrete contractor applies a medium-broom finish on the surface of the concrete. This is very important to a good physical bond of the sport coatings. A steel-troweled finish is too smooth and will also raise the chances of peeling surfaces. If the concrete is already in place and doesn’t have a medium-broom finish, you can use specialized equipment to achieve sufficient texture. The most commonly used piece of equipment is a shot blaster. For more information, check out our dedicated page on shot blasting concrete court surfaces.
Allow Full Cure Before Coating Application
The curing process of concrete is a chemical reaction that takes 28 days to complete. During the process, quite a bit of water is escaping from the slab and depositing high-alkaline salts on the surface. It is important to allow a full 28 day minimum cure, prior to moving forward with coating application. Also, after the full cure and prior to application of coatings, the concrete slab must be acid etched (or acid washed). This helps to create a neutral PH on the surface for an ideal chemical bond of coatings. This is fully explained on our page, acid etching concrete sport surfaces.
One more note on curing, avoid using curing compounds on concrete court surfaces. Once the concrete is poured, it will instantly begin to losing water via evaporation. If the temperatures are hot, water will leave the wet slab quickly, and this could lead to surface cracking (like mud cracking in a puddle). To prevent this, most concrete contractors spray curing compounds on the surface to slow down the evaporation of water. Many curing compounds are made up of oil based or incompatible materials that can leave a residue on the the concrete surface. This residue, or film, can potentially cause a bond breaker and lead to failure of the acrylic sport coatings. To avoid this situation, make sure the concrete contractor moisture cures the slab. This is performed by keeping the slab wet after pouring, with a covering of moistened burlap, a polyethylene sheet, or other curing paper. After 7 to 10 days, it can be allowed to dry and cure under normal conditions without the keeping the slab moist.
Not sure if curing compounds have been used, or you know they have been used? The surface can be shot blasted to remove any bond-breaking films. Note, you can pour a small amount of water onto the concrete slab to see if water beads up on the surface. If it does, there is likely a curing compound or sealant on the surface.
Application Of Concrete Primer & Sport Surfaces
At this point, the concrete slab should be ready to receive the sport surfacing system. Once the surface is clean and dry, apply one coat of SportMaster Acrylic Adhesion Promoter. This product acts as a concrete primer and helps the SportMaster color coating system adhere to the concrete. It also helps to lock down potential concrete powder, or efflorescence, that may migrate into the color coating “paint” layers and leave a hazy color hue.
After the Acrylic Adhesion Promoter dries, Acrylic Resurfacer and the colored surface coatings can be applied. There is no special timing required with Acrylic Adhesion Promoter. The successive coatings can be applied as soon as it is dry to the touch, or on another day thereafter.
One or two coats of Acrylic Resurfacer is usually sufficient to fill broom patterns and concrete surface texture on a new concrete court surface. Follow that with SportMaster color coatings, 2 coats minimum, and striping to complete the new concrete recreational court surfacing.
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.
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.
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.
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.
Sport and game courts are as popular as ever, especially with the extreme growth of sports like pickleball and continued popularity of basketball, tennis and multi-sport games and courts.
SportMaster has a multitude of durable and vibrant acrylic surfacing systems that are designed for asphalt or concrete courts. Each substrate has a somewhat different approach to preparation, prior to application of the sport surfaces. We are going to discuss a common step that is required when coating concrete courts for the first time. This process is called acid etching or acid washing.
What Is Acid Etching? | Concrete Court Surfacing
Acid etching is the process of pouring a mixture of water and acid on a fully cured concrete slab. Generally, either muriatic or phosphoric acid is used, but muriatic is a bit easier to find. In a nutshell, acid etching promotes an ideal environment for chemical bond of coatings to concrete.
Why do I Need To Acid Etch My Concrete Court Surface?
Concrete goes through a chemical curing process after it is poured. It takes 28 days for a concrete slab to completely cure. There is a good bit of water in the concrete mix and as the concrete is curing, water is continuously wicking and evaporating upward and out of the slab. As the water is migrating upward, it brings efflorescence, or salts, that reside in the concrete. After the initial curing phase is complete, there is a crust of efflorescence on the surface of the concrete.
Lesson In PH & Surface Chemistry
PH, or “potential of hydrogen” is the scale of acid vs base. The PH scale goes from 0 to 14, whereas 0 is very acidic and 14 is very basic (alkaline). For ideal chemical adhesion, coatings prefer a neutral environment. This would be 7 on the PH scale. When concrete cures, the surface crust or salt deposits, are very high in alkaline (a PH around 13.5). The process of acid etching neutralizes the high alkaline crust and brings the surface PH back to neutral. The acid washing process also helps to break down and rinse away the powdery efflorescence. This also prevents flaking or peeling of coatings & migration of powder into the color coatings resulting in a cloudy appearance.
How To Acid Etch A Court | Pickleball – Basketball – Tennis
In this section, we will outline how to acid etch a concrete court surface. But first, here are a few pointers:
Make sure to acquire and wear adequate safety gear, when working with acid. Thick rubber gloves, safety glasses, and relevant clothing and boots. Avoid breathing in the direct fumes of concentrated acid and ensure that you have plenty of air flow when inside.
As a general guideline, it should take around 2 to 3 gallons of acid to etch a smaller court, like a 30′ x 60′ pickleball court & around 8 to 9 gallons for a full tennis court (60′ x 120′).
Protect any sensitive plants or surrounding materials around the border of the court. Even though you will be rinsing off acid that is very diluted and has already reacted with the surface, it’s a good idea to minimize contact as much as possible.
Step 1: Spray water on the court to dampen the surface. This helps the mixed acid and water to flow and better penetrate the surface.
Step 2: Properly mix the acid and water, following the dilution measurements on the acid bottle. There should be directions for “masonry etching” on the bottle instructions. Remember to fill the empty bucket with water first and then pour the correct amount of acid into the water. This helps to prevent splashing of acid.
Step 3: Pour the acid & water mixture onto the concrete, working in small areas or sections at a time. If you’re able to have a helper, have the 2nd person immediately broom the solution around with a push broom to make sure the acid comes into contact with every square foot of concrete. Make sure that you don’t pour the acid mixture and expect it to span a long distance. Instead, pour around a small zone in a tight “s” pattern to ensure direct contact with the surface. Since the acid mixture reacts instantly with concrete, the potency diminishes as it spreads.
You will notice a cloudy appearance in the liquid and minor bubbling reaction, which means the acid is working to neutralize the surface salts.
Step 4: As you move on from section to section, you will notice the reaction dissipates in the previously treated area. At that point, you can rinse those areas off to flush surface contaminants and move the neutralized acid solution off the court surface. If possible, it’s best to start on the high end of the court and slowly move all of the water toward the low end of drainage. If possible, try to keep the entire court damp throughout the process, which keeps the sediment from sticking to the surface.
Step 5: After you have etched the entire court surface, and rinsed away most of the remaining acid mixture and sediment, it’s always good to do a final rinse of the entire surface. This ensures a completely clean surface, free to any potential acid or other contaminants. If you’re indoor and don’t have available drains, a floor cleaner machine can be used for a good final cleaning.
*Remember to protect and avoid adjacent concrete areas that are not receiving the sport coatings, as the acid can create a different color or appearance to exposed concrete. This is hidden when coatings are applied over the acid etched play areas.
Common Misconception About Acid Etching
Many people think that acid etching creates a physically textured surface for the coating to adhere. This is not the case, as the actual purpose was established earlier in this bulletin. It is still very important for the concrete surface to have a medium-broom finish or similar. That is very important for physical adhesion of coating systems. Remember, the two most importance factors for good adhesion of sport coatings is:
A good surface texture/profile for physical adhesion
Neutral surface PH for excellent chemical adhesion
Another common issue seen on athletic court surfaces arises from asphalt impurities, most commonly clay balls. In this bulletin, we will explain the occurrence of asphalt impurities & clay balls on sports court surfaces.
The appearance of clay balls begin with small bumps that appear in random areas of the court surface. When you push on these bumps, they feel hard and do not give. If you carefully cut into the bumps, you should discover a small pile that looks like ash.
How to clay ball deposits get below the court surface?
Asphalt is made up of rock (mostly limestone, with some other aggregates). It is held together by asphalt binder, derived from the oil refining process. Clay deposits are naturally occurring, and heavier in certain regions throughout the ground and rock quarries. When excavating the limestone, it is impossible to remove 100% of the clay that is laced within. As shown in the picture below, you can see random pockets of clay in the uncoated asphalt voids.
Why do the court surface bumps appear?
Asphalt is a porous pavement and will allow sub-surface moisture to breathe through it. Acrylic sport surfacing systems are semi-permeable and will also allow a moderate amount of moisture to breathe through and escape. Properly constructed courts should be pitched at 1% for drainage, but there is still ground moisture that travels up through the slab. When the surface of the court is heated from the sun, it draws moisture up from beneath the court in a vapor state. As the moisture is migrating through the asphalt, it is absorbed into the clay deposits and the acrylic surfacing layers slow down the escape. During the process, the clay balls swell and create the visible lumps on the surface.
How to remove clay balls from court surface
So, how do you remedy the situation and remove clay balls from the court surface? This is usually just an aesthetic issue and normally not a problem that will affect play and the ball bounce. If it becomes a problem, or when it is time to resurface the court, the following procedures can be performed:
Scrape the surface bumps with a long-handled scraper, or similar tool, to open and expose the clay deposits.
Use a pressure washer to blast out the clay or foreign materials
If the clay balls are not creating issues with play and you can wait to remediate the clay balls situation, it will allow time for any potential swelling reactions. If you do this as soon as it happens, and resurface the court, others may pop up shortly after. You can remove them as they show up, but you will likely see the touch-up from the different of texture and color.
Avoid Recycled Asphalt For Sport Surfaces
Other asphalt impurities can also create problems with court surfaces. If possible, avoid using recycled asphalt as it may contain unknown foreign items (i.e. shingles and other various materials). It is also important to seek out experienced sport construction companies, as they may know what quarries to avoid based on past history of clay deposits and foreign materials. Contact us for free referrals to qualified installers.
Question: Are acrylic sport surfaces breathable and permeable?
Answer: Yes, SportMaster 100% acrylic sport surfaces are breathable and classified as semi-permeable.
Acrylic Sport Surfaces for Athletic Surfacing
SportMaster Sport Surfacing systems are produced using high-quality, 100% acrylic resins. This is the industry-standard for sport surfacing on asphalt and concrete tennis, basketball, pickleball, and many other athletic and recreational court surfaces. One of the main reasons for this is the fact that 100% acrylic resins are semi-permeable and allow a small to moderate amount of vapor transmission.
It is important to know that this does not mean you can have poor drainage and slope on a court surface and expect the acrylic coatings to “fix the problem”. As a leading producer of acrylic sport surfaces, we strongly recommend following the construction guidelines of the American Sports Builders Assocation (ASBA). The ASBA maintains an updated library of publications that demonstrate the right way to build tennis, pickleball, and athletic courts, along with running tracks and other recreational surfaces. If athletic surfaces are not properly engineered, drained, and constructed, our (and any other) sport surfacing systems may exhibit bubbles, blisters, or failure.
Asphalt & Concrete Athletic Court Construction
The recommended slope, for asphalt & concrete athletic court construction, is 1%. This should be 1″ fall per every 10 feet of surface, in one direction. This is enough pitch to allow runoff of water, without creating issues for the players. Courts will be able to drain quickly and re-open for play. Plus, acrylic coatings do not like to be constantly submerged, or the coatings will start to breakdown and wear at a quicker rate.
It is very important to have a professional drainage plan and make sure that water coming off of the court doesn’t accumulate beneath the slab. Perimeter drains or other drainage plans, to take the water away from the courts and into the drainage system, is necessary. Concrete courts should also be built with a vapor barrier to prevent hydrostatic pressure, in the form of water vapor, beneath the slab. When the sun heats up the court surface, sub-surface water turns to vapor and creates vapor pressure to escape. If enough water builds up beneath the slab and pushes upwards, it can create bubbles and blisters in the coatings and lead to peeling.
Question:Why do tennis courts crack under the tennis net?
Answer: Tennis courts often develop cracks under the tennis net for a few related reasons:
Tension on the cable that supports the tennis net
Concrete footers that hold the tennis net posts in place
Tennis court net posts are secured by a concrete footer, when installing an asphalt tennis court. The footer can be in place prior to the asphalt paving process or it can be installed after the tennis court has been paved. There is a plastic or galvanized sleeve set within the net post footer, which makes the net post removable and easily replaceable.
Tennis nets are suspended by a cable, which is secured to the dead-end post, and wound or tightened with a wind assembly from the other post. The average recommended tension on the net cable is 400 to 450 lbs. The sustained tension from the cable tends to pull the post footers in and can often create cracks into the surrounding asphalt. Square or rectangular footers will often send cracks from the corners into the surrounding asphalt. Round footers can also create cracks under the net, so it’s best to consult with an experienced court builder or resurfacing company to discuss the proper way of installing net post footers.
Here are some diagrams that show the right way to shape and install the court footers, to minimize inward shifting:
Concrete & Asphalt Surfaces
Concrete and asphalt expand and contract at a different rate. When concrete is place next to asphalt, the gap between them will likely exhibit movement. This can also happen with light posts, fence posts, shade structures, and other amenities.
Here are a few more pictures showing cracks under and around the tennis court net line:
Filling Cracks On Tennis Courts
Once the cracks have started, it’s all about maintenance. SportMaster produces easy-to-apply crack fillers and sealants. These products are not a structural fix, but more of a “band-aid” for cracks. They will minimize the amount of water that flows through the cracks and into the base of the court. Water can loosen the compacted base, and expand to create more damage during freeze-thaw periods.
If the cracks are larger than an inch wide, and very deep, we recommend having a professional tennis court contractor take and look and provide recommendations. Many times they will need to fill the large cracks with concrete, asphalt, or other specialized means. At some point, reconstruction or an overlay is the best long-term solution.
SportMaster was fortunate to take part in a basketball court surface mural project in Philadelphia, PA. The project took place at Waterloo playground, with the help of Jeffrey Tubbs (co-founder of MTWB – Make The World Better). Jeffrey saw another mural court on Instagram, and sold the idea of bringing a mural basketball court to Philly. You can read more details about the project at the MTWB website. Check out the cool video and amazing process to create this court surface mural.
SportMaster ColorPlus Fusion System
One of the unique benefits of the SportMaster ColorPlus system is the ability to use concentrated liquid pigments to tint neutral-based coatings. This minimizes the amount of waste and overage, when it comes to specific colors. This is ideal when working on court murals and jobs that require “custom” colors. Most brands require specific batch sizes to create certain colors, but with the ColorPlus Fusion system, there are over 100 standard colors available. And, you can create much smaller amounts by easily measuring and mixing pigments.
Another increasingly poplar trend is asphalt muralists. This is a way to enhance the charm of plain old asphalt. Whether it’s single colored asphalt pavement or areas with intricate designs, this helps to provide a much nicer feel. Here is a short list of benefits:
Brighter appearance and “richer” look
Great for areas being cleaned up and revitalized
Most colors are cooler than black pavement, lowering pavement temperature and heat islands
Custom designs, drawings, & logos
Great for marketing outside of a business.
Also works to seal, protect, and extend the life of pavement
These sand-filled coatings provide safer, non-slip texture when dry or wet.
Here is a detailed mural, on asphalt, by Yetti Frenkel. Check out more of her artwork and murals at https://yetti.com/
Manufacturer Support | SportMaster
If you are interested in custom courts, asphalt murals, or any other unique pavement coating designs, feel free to contact us. SportMaster has a large network of company representatives and installers throughout the US and abroad.
We can help with project specifications & scope, along with training and qualified contractor referrals.
There are many reasons that people request colored asphalt sealers. Even though the most common form of asphalt sealers are black, there is a growing need and desire for asphalt color coatings.
We have been producing a full line of asphalt coatings for nearly 50 years, but our ColorPave system is one of the fastest growing lines over the last 10 years. The truly unique thing about ColorPave is that it can be used in so many different areas and it covers a large variety of applications.
Benefits of Color Coating Asphalt
There are quite a few benefits of color coating asphalt, but here is a short list of the most popular reasons:
Light colors to lower the asphalt pavement temperature (minimizing heat islands)
Highlighting special areas or zones (color coded areas)
Cleaner & brighter look to asphalt areas
Driveway or parking lots with combo sports court areas (i.e. driveway basketball court)
The ColorPave System | Asphalt Color Coating Paint
The ColorPave system is a 100% acrylic coating system for asphalt areas. It is durable enough for moderate vehicle traffic and available if a few different formulas (ColorPave & ColorPave HD 500)
ColorPave has been around for over 20 years, and has been used in a large variety of applications. From military to public & private installations, ColorPave provides an attractive, safe, and durable colored finish on asphalt pavement.
Parking Lot Color Coating
Color coating parking lots & parking garages is another use for the ColorPave product line. The social media giant, facebook, chose ColorPave to color coat their asphalt parking garage at the new corporate headquarters in Menlo Park, California. This provided a inviting atmosphere for employees while sealing and extending the life of their pavement.
Stamped Asphalt | Color Coatings
Color coating stamped asphalt is generally performed with our ColorPave HD product. It is a cross-linking acrylic, available in multiple colors, and fortified with silica sand for non-slip safety and durability. This system dries very fast and has a very high amount of solids for long-wear and moderate vehicle traffic.
Tennis court surfacescan be customized to achieve very specific speed of play. The ITF (International Tennis Federation) has a technical testing program to classify all kinds of tennis court surfaces into court pace ratings (CPR). Here is the current chart of CPR and pace category:
Category: Slow | CPR less than or equal to 29
Category: Medium-slow | CPR 30-34
Category: Medium | 35-39
Category: Medium-fast | 40-44
Category: Fast | greater than or equal to 45
Customizing Acrylic Court Surfaces
Most tennis court surfaces can be customized to some extent. However, acrylic court surfaces have the widest flexibility of options. Due to the ability of acrylic coatings to suspend different blends of silica sand and specialty aggregates, they can generally achieve all ITF paces with the correct combination of texture.
Professional Tennis Tournament Surfaces
When it comes to professional tennis tournament surfaces, the speed of play is very important. The court surfaces are usually kept consistent to the other tournaments in the same series. This enables the players to hone their game on courts that perform similarly, prior to the most prestigious event at the end of the swing.
College & University Tennis Court Surfaces
College & university tennis court surfaces are also commonly resurfaced to meet specific court speeds, depending on the current strengths and weaknesses of the players. Many times, the tennis coach will prefer a slower court to help the home team if they lack power serves and pride themselves on volley or returning the serve. On the other hand, fast court surfaces favor the player with a fast serve.
Recreational Court Surfaces | Safe Texture
Recreational court surfaces normally require a safe texture, and are usually installed at a medium speed of play. This ensures that the court surfaces have enough grip for common dry or wet conditions. If players happen to play on the courts during or after rain, or when dew is still present, there will be minimal chances for slipping and falling from slick surfaces. This surface pace is well suited for all sports from tennis, basketball, and pickleball to recreational play.
Sport Surfacing Systems | Installers
To learn more about speed of play and creating the ideal surface conditions for your sport surfacing systems, contact a SportMaster representative. They can assist with apples to apples specifications and put you in touch with an experienced contractor to install the coating system to the manufacturer specified pace.