Why Is The Crack Filler Not Drying On My Tennis Court?

Question: Why Is The Crack Filler Not Drying On My Tennis Court?

Answer: Moisture is, most likely, wicking up from beneath the court surface, and it is keeping the crack filler from drying all the way through. Structural cracks, in asphalt or concrete tennis courts, go through the entire slab. This creates an easy way for surface water to drain into the base, and sub-surface moisture to evaporate out of the base. Most tennis court crack fillers are water-based acrylics. Water is the vehicle that allows application of the crack filler, and then evaporates to leave the dried crack filler in place. When crack fillers and sealants are applied and begin to dry, they form a film on the top first. Then, the rest of the water takes some time to dry throughout. The following conditions also affect the speed of drying:

Temperature (air and ground temperature)
Humidity
Size of the crack (width and depth)
Amount of moisture in the ground, beneath the court.
Wind can also impact drying
Type of crack filler

Pourable Crack Sealants generally contain more water to help the crack filler flow into the cracks. These can take a bit longer to set up and can be more impacted by sub-surface moisture wicking. If you are going to pressure wash the cracks before applying crack fillers, make sure to allow two or three days of dry conditions, before applying the crack sealants. Also, avoid crack filling after or immediately before heavy rains. Poor or missing drainage systems around the court can fail to move water away, and leave saturated ground under the court. This can contribute to crack filler drying problems.

Trowel grade crack fillers, like SportMaster Acrylic Crack Patch, are high in solids, tend to dry quicker, and have more body to fill larger cracks. This product would dry quicker in comparison to a pourable crack sealant. Acrylic Patch Binder is mixed on-site with sand and portland cement, and would also be a great choice for a faster-drying tennis court crack filler.