In-ground trampolines are trampoline frames that are set in a hole with the surface almost flush with the ground. A trampoline installed this way is considered safer because the distance you would fall off the trampoline is greatly lessened. You can install any regular trampoline in the ground in the same way as the special in-ground ones are installed.
Dig a hole a little wider than your trampoline and a few inches shorter. When the trampoline is in the hole, its edge should rise an inch or two above the ground, and there should be about 4 inches between the wall and the frame.
Use a shovel to make the hole smooth along the walls. Put the frame of the trampoline in the hole to make sure you keep the hole level.
Dig holes with an auger around the perimeter of the hole for the support posts. You should place the holes 3 feet apart from each other and 1 foot deep.
Cut four-by-four posts on a table saw to the appropriate length to make the supports. The supports should be the height of the hole plus 1 foot for inserting into the ground.
Stand the four-by-four posts in the holes and fill the each of the holes with concrete. Make sure the posts are straight. The concrete will need to set overnight to harden.
Place a length of plastic sheeting behind the support posts and in front of the wall of the hole. The sheeting should run all around the hole and cover the wall entirely and hang over the top edge of the hole.
Insert chicken wire between the sheeting and the support posts. The chicken run should cover the walls of the hole in the same way as the sheeting.
Fit two lengths of two-by-fours horizontally between every vertical post. These braces should be placed between the top of the posts and at the middle of the posts.
Cut the ends of the two-by-fours with a radial mitre saw to allow for the curves of the hole for a circular trampoline. The angle you have to cut the end to will depend on how big the hole is.
Attach the horizontal braces to the posts with an offset nail gun.
Pull the excess sheeting and chicken wire over the top horizontal brace and staple them down. Use a staple gun to securely hold the material against the brace.
Cover the floor of the hole in plastic sheeting, stapling it to the wooden frame all around the hole.
Drop the trampoline into the hole. Pack the dirt that you dug out around the trampoline. The dirt should be sloped downward, away from the trampoline.
Choose a part of your property that isn’t used lot to avoid it being a nuisance when walking around.
Do not install the trampoline near concrete or other dangerous materials that can hurt you if you fall onto it.