If you are considering purchasing a trampoline, you are probably also considering how to install it: above, or below ground. Below ground means that the surface of the trampoline, when empty, is level to your yard. This is often an attractive option to many homeowners since the trampoline looks more "built-in", isn't as visibly noticeable, and also makes mowing easier since there is no trampoline to move or mow under.
It is easy to assume that an in-ground trampoline is safer than one placed above ground. It is true that the trampoline is closer to the ground by a few feet, but remember that it is still possible to bounce off of the trampoline, hit the ground, or other nearby objects. Even when installing a trampoline at ground level, we strongly encourage the use of a safety enclosure net.
When you bounce on a trampoline, you are moving quite a bit of air as the surface of the trampoline flexes up and down. Since that air does not have as much room to escape now that it is underground, it causes the cushioned pad to flop on each jump. To most people, this is not a bother. But we do offer a vented pad for 14' trampolines which makes a big difference.
If you install your trampoline at ground level, remember that without a safety net it will be much more accessible to small children. Children under the age of six should never use a trampoline, and all children should be supervised while bouncing.
The final consideration is the cost, complexity, and permanent nature of an in-ground trampoline. First and foremost, installation will require the digging of a pit the size and depth of your trampoline, which can easily mean 400 square feet of dirt or more. You will also need to have the location marked by your local utility companies before digging, and some cities and towns may require a permit. Retaining walls are also necessary to ensure that dirt from the sides of the pit do not sink into the pit over time due to erosion and foot traffic. We sell a trampoline retaining wall kit that makes this part easy!
Each installation situation is different. If you are interested in installing your trampoline at ground-level, we highly suggest consulting a licensed landscape contractor.