How to Repair Cracks and Delamination of Silicon PU Basketball Courts?

Silicon PU basketball courts are widely used in various sports venues due to their excellent sports performance and good weather resistance. However, with the passage of time and the influence of external environmental factors, problems such as cracking and delamination may occur on silicon PU basketball courts. This not only affects the aesthetics of the court but also reduces its performance and may even pose safety hazards to users. This article will introduce in detail the repair methods for cracking and delamination of silicon PU basketball courts to help you rejuvenate the court.

I. Analysis of the Causes of Cracking and Delamination of Silicon PU Basketball Courts

Before proceeding with the repairs, let’s first understand the common causes that lead to these problems on silicon PU basketball courts:

1. Problems with the Foundation: If the foundation ground of the court is uneven, has cracks, or is not strong enough, after the silicon PU material is laid, the deformation of the foundation will be transmitted to the silicon PU layer over time, resulting in cracking and delamination. For example, if the foundation ground is not fully compacted during construction and settles later, it is prone to causing damage to the surface of the silicon PU basketball court.
2. Poor Quality of Materials: The use of silicon PU materials that do not meet the standards may have defects in their adhesiveness, flexibility, and durability. For example, inferior materials are likely to lose their elasticity when exposed to temperature changes or long-term exposure to sunlight and rain, thereby resulting in cracking and delamination.
3. Improper Construction Techniques: During the construction process, factors such as uneven application thickness of each layer of material, inappropriate time intervals between layers, and unsuitable construction environment temperature and humidity can all affect the overall quality of the silicon PU basketball court. For example, when constructing in a humid environment, moisture may be trapped between the material layers, and when the temperature rises, the water vapor expands, causing delamination.
4. Improper Use and Maintenance in the Later Stage: Long-term exposure to heavy machinery rolling, scratching by sharp objects, or lack of regular cleaning and maintenance can also accelerate the damage to the silicon PU basketball court. For example, frequently parking vehicles on the court, the weight of the vehicles will exert huge pressure on the court surface, making it prone to cracking.

II. Preparation Work before Repair

1. Preparation of Tools and Materials

• Tools: Broom, blower, scraper, grinder, vacuum cleaner, mixer, spray gun, roller brush, etc.
• Materials: Silicon PU repair materials (select the corresponding color materials according to the color of the court), interface agent, sealant, quartz sand, etc

2.Cleaning of the Site

Use a broom to sweep away the dust and debris in the cracked and delaminated areas and their surrounding areas. For some stubborn stains that are difficult to sweep away, a blower can be used to blow them away. Then, carefully scrape off the loose and detached silicon PU materials with a scraper, taking care not to overly damage the surrounding intact areas. After cleaning, use a vacuum cleaner to thoroughly clean the site to ensure that there is no dust or debris left.

III. Repair Steps for Cracking of Silicon PU Basketball Courts

  1.Treatment of Cracks

For narrow cracks (with a width less than 3mm), the silicon PU repair materials can be directly used to fill them. Stir the repair materials evenly according to the instructions, and then use a spatula to fill the cracks with the materials, making the materials as flush as possible with the surrounding silicon PU surface and compacting them. For cracks with a width greater than 3mm, the cracks need to be cut into a «V»-shaped groove first. The depth of the groove is generally 1 – 1.5 times the width of the crack. After cutting, use a blower to clean the dust inside the groove, and then fill the stirred silicon PU repair materials into the groove and compact them to fill the groove evenly.

  2.Surface Grinding

After the repair materials have dried (generally taking 24 – 48 hours, depending on the environmental temperature and humidity), use a grinder to gently grind the repaired area to make the transition between the repaired area and the surrounding silicon PU surface smooth. During the grinding process, pay attention to controlling the grinding force and range to avoid causing new damage by over-grinding.

3.Application of Interface Agent

Apply a layer of interface agent on the ground surface after grinding to enhance the adhesion between the repair materials and the original silicon PU layer. The interface agent should be evenly applied to avoid missing any areas or applying it too thickly. After application, wait for the interface agent to dry, which generally takes 1 – 2 hours.

  4.Overall Repair and Coloring

After the interface agent has dried, adjust the color of the silicon PU repair materials according to the color requirements of the original court and stir them evenly. Then use a spray gun or roller brush to evenly apply the repair materials on the repaired area and its surrounding area within a certain range, making the repaired area consistent with the color and surface flatness of the entire court. The application thickness should be the same as that of the original silicon PU layer, generally 1 – 2mm. After application, let it dry naturally, and the drying time is about 24 hours.

IV. Repair Steps for Delamination of Silicon PU Basketball Courts

  1.Cleaning of Delaminated Areas

Peel off the delaminated silicon PU materials in whole pieces. If some materials are still firmly attached to the foundation ground during the peeling process, they can be carefully scraped off with a scraper. After cleaning, check whether the foundation ground has problems such as loosening and sanding. If so, the foundation needs to be repaired and strengthened first.

  2.Treatment of the Foundation

After sweeping and vacuuming the foundation ground, apply a layer of sealant on the delaminated area and its surrounding area within a certain range to enhance the adhesion between the foundation ground and the silicon PU materials. The sealant should be evenly applied, with a moderate thickness, generally 0.5 – 1mm. After application, wait for the sealant to dry, which generally takes 2 – 3 hours.

  3.Relaying of Silicon PU Materials

Relay the silicon PU materials according to the construction process requirements of the silicon PU basketball court. First, apply a layer of silicon PU primer on the foundation ground after the sealant has dried. The primer should be evenly applied, with a thickness of about 0.3 – 0.5mm. Wait for the primer to dry (about 1 – 2 hours), and then lay the silicon PU middle layer materials. Add an appropriate amount of quartz sand to the middle layer materials as needed to increase the friction and strength of the court surface. When laying the middle layer materials, pay attention to controlling the thickness and flatness, generally with a thickness of 1 – 2mm. After the middle layer materials have dried (about 24 – 48 hours), finally apply the silicon PU topcoat. The topcoat should be evenly applied without dripping, with a thickness of about 0.3 – 0.5mm. After application, let it dry naturally, and the drying time is about 24 hours.

V. Maintenance after Repair

1. Daily Cleaning: Regularly sweep the silicon PU basketball court and use a neutral cleaner and a soft brush to remove the stains and dust on the surface. Avoid using strong acid, strong alkali and other corrosive cleaners to prevent damage to the surface of the silicon PU materials.
2. Avoiding Heavy Pressure and Damage by Sharp Objects: Prohibit parking vehicles, piling heavy objects or conducting other activities that may cause heavy pressure on the court surface on the court. At the same time, remind users to avoid wearing shoes with spikes when entering the court to prevent the surface of the silicon PU from being scratched by sharp objects.
3. Regular Inspection: Regularly conduct a comprehensive inspection of the silicon PU basketball court to promptly discover and handle possible new problems such as small cracks and slight delamination, and control the damage degree within the minimum range.

Through the above steps, you can effectively repair the cracking and delamination problems of silicon PU basketball courts. During the repair process, strictly follow the instructions of the materials and the construction process requirements to ensure the repair quality. At the same time, strengthen the maintenance after repair to extend the service life of the silicon PU basketball court and provide a safe and comfortable sports venue for users.

If you encounter any problems during the repair process of the silicon PU basketball court or need professional technical support, it is recommended that you consult a professional silicon PU basketball court construction team or material supplier. They can provide you with more detailed and professional guidance and assistance. Let’s work together to maintain the good condition of the silicon PU basketball court and promote the vigorous development of sports.