Playground Safety Starts Below The Surface

Hello everyone, this is JW. I hope your day is going well.

Hey, when you look at a playground, you see the equipment and the finished surface, but what’s underneath that surface deserves just as much attention when building a safe synthetic turf playground. Fall protection relies on the correct, specified, and properly installed impact-absorbing surface, along with appropriate testing and ongoing maintenance. But what about the sub-base? How important is that subbase?

Well, playgrounds take a beating. Children run, they jump, pivot, and land in the same areas every day, especially beneath swings, at slide exits, and around climbing equipment.
That repeated activity puts the foundation to work.

Subbase stability and proper compaction are a must.

If the materials beneath are loose, unstable, or contaminated, they can shift, settle, or flood. Over time, these issues manifest as depressions, uneven areas, stress seams, and potential trip hazards. Covering an unstable foundation with synthetic turf or shock padding does not address the underlying problem.

You must start with the existing soil, the subgrade, as many call it.
Address what it’s made of and whether it can handle high compression with superior drainage.
If the sub-base is in excellent condition to serve as a foundation, use a minimum of four inches of compacted, three-quarter-inch crushed limestone aggregate, topped with a small layer of three-eighths-inch-minus mixture to ensure a smooth, uniform surface.

The aggregate selection and finishing layer must work with the drainage design and the playground surfacing manufacturer’s requirements. Some soil conditions require a deeper base or additional stabilization because they’re high in expansive clay and conglomerates.

Then comes the part you cannot rush… compaction.

Place and compact the aggregate in manageable layers, called lifts, so that your equipment can compact through their full depth. The compacted aggregate provides a stable base where water can flow rapidly through it if flooding occurs. When the ¾” aggregates are in place and compacted, I recommend topping the compacted surface with a small layer of approximately 1 inch of three-eighths-inch minus mixture. This locks in the top surface and prevents movement of the compacted materials below. Make sure you wet the compacted aggregates prior to adding the 3/8” minus mixture so that you will end up with a locked-in, smooth and creamy surface to place your Tiger Grids or Tiger Shock Pads on top of.

My minimum recommendation is 90 percent compaction below playground surfaces.
Also, pay particular attention around equipment footings, drains, repaired trenches, and perimeter edges. These areas may need special attention to prevent future settlement.

And remember… a stable foundation is essential for the integrity of any playground system… from the bottom dirt to the top of the safety surface.

This is ASK JW, and I’ll see you on the next one!

JW OUT!