Building a backyard splash pad has close to the same level of difficulty as building a swimming pool. Both systems involve the installation of a pump and filter system that recirculates sanitized water. While installing the surface treatment for a splash pad is much easier than pouring concrete for a swimming pool, the layout and placement of the PVC pipes to each spray head and bubbler is much more intricate. A variety of non-slip surfaces, such as textured concrete, pavers or rubber can be used. The most important design element is an adequate slope for proper drainage.
Contact your local building department to obtain a building permit and determine if a licensed electrician is required for the layout and connections of the electrical system. Prepare a sketch of the layout of equipment and the underground piping. The spacing between pipes, valves and manifolds needs to be accurate. Consult the installation guide provided with your splash pad installation kit.
Mark out the area for the splash pad (a typical size is 10 feet by 10 feet), the location of the holding tank, pump (above or below ground) and filter. Dig out at least 18 inches of soil under the splash pad area, trenches for the layout of piping and electrical cable, and dig a hole deep enough for the holding tank. For a gravity-fed drainage system, the top of the holding tank should be a minimum of 6 inches below the bottom of the area drain. If the pump is to be at the surface level, lay down a hard surface (concrete, pavers or stone) and determine how it will be protected from weather conditions (for example, the pump could be located in a shed). If the pump will be installed below ground, it should be encased in a concrete bunker.
Install all parts of the splash pad kit according to manufacturer's instructions. Install the pump, filter and holding tank in the proper locations. Layout the electrical cable, but do not attach it to power supply until the final step.
Lay out the PVC pipes, connecting spray heads, pump, filter, valves and holding tank. Ensure that the PVC pipes for the spray heads extend well above the desired finish elevation for the splash pad area. Install the area drain so that it will be at the lowest elevation on the finished surface.
Backfill the area under the splash pad until it is 10 inches below the desired surface level of a concrete pad, or until 8 inches below if you are using concrete pavers with a 2-inch height. Lay down a 6-inch-deep layer of clear aggregate, then pour the concrete pad (4-inch depth) or lay down a 1/2-inch layer of sand then the concrete pavers. Take care to slope the surface area for good drainage (a 2-inch drop for every 9 feet of distance), and to ensure that there is a tight fit around the PVC pipes and area drain.
Cut the PVC pipes extending through the finished surface to the appropriate height, then attach the spray heads. Install the cover for the area drain. Patch any open areas around the spray heads or the area drain with concrete.
Hook up and make final connections for the electrical system. Do a safety check to see how the system operates before use. If the splash pad will be run by a remote control, install it according to the manufacturer's instructions.