There is a sink hole under my playground rubber surface

Sink holes under poured in place surfaces often happen when the substrate is compacted crushed stone (although it can theoretically happen when the substrate is asphalt as well, though I personally have never seen that happen). Often times, it is the work of water carving channels in certain spots under the rubber, displacing the stones acting as a base for the poured in place rubber. When that happens, when you step on the rubber, you feel like it's about to give, and when the tensile strength of the rubber reaches its limits, it actually does. So the question becomes: How do I best repair a sink hole under poured in place rubber?

Sunken poured in place rubber surface

Many contractors would try to recreate the same environment before the stones were moved. In other words, add more crushed stone to fill the void, then install base layer, then wear layer using any of our poured in repair kits.   I prefer another approach. Fill the void with black EPDM rubber.  I use black of course because it's the cheapest rubber and will never be seen. I sue rubber, not crushed stone at this level because the logic is if that's the channel the water is creating, and that's the weakest link in my surface, it will happen again. The stones will be moved again, but not the rubber, since it will cure into one huge clump, and will act as great support for what's above. I then add the right thickness of base layer material to get my impact attenuation, and finally top everything off with a wear layer rubber in a color that closely matches what I had or I would create a design using a different color, like a splash mark in blue to make it look like it was designed like that. 

If you have any further questions on how to repair a sink hole in your rubberized surface, feel free to call me at 203-659-0456 or email me at