Installing an in-ground trampoline is a realistic weekend project, but only if you plan out the dig and use the correct equipment. This process takes more work than a standard backyard setup. You have to excavate a tiered dirt bowl, set up water drainage and perfectly level the steel frame so it sits flush with the grass.
In this step-by-step guide, we’ll explain how to choose the right location, excavate the pit, install the retaining wall and frame, manage airflow and drainage, and avoid some of the most common DIY installation mistakes homeowners run into along the way. Our goal today is to help you set realistic expectations before you even pick up a shovel.
Before You Start: Is DIY Realistic?
Before renting equipment, it helps to set realistic expectations for the project. Installing an in-ground trampoline usually takes between 12 to 24 hours of active labor, depending on your soil and equipment.
When DIY makes sense:
- You have access to (and feel comfortable operating) a mini-excavator.
- You have a plan for hauling away 3 to 4 cubic yards of excavated dirt.
- Your yard has relatively soft soil and decent natural drainage.
When you might want to hire professionals:
- You are dealing with heavily compacted soil, solid rock, or caliche.
- You don’t have a truck to haul away the leftover dirt.
- You want the project finished in a single day without the physical strain.
Tools & Materials Checklist
While some homeowners successfully bury standard above-ground trampolines by building custom retaining walls out of treated wood or cinder blocks, this can be incredibly labor-intensive, and wood tends to warp over time due to ground moisture.
For the most straightforward and reliable installation, we generally recommend using a dedicated in-ground trampoline kit, which comes with an interlocking retaining wall designed specifically to fit the frame.
What you will need:
- Excavation: A mini-excavator (highly recommended) or trenching spades and standard shovels.
- Measurement: A laser level (or a long straight-edge with a heavy-duty bubble level) and a tape measure.
- Hardware: A power drill and the self-tapping screws provided with your kit.
- Drainage: Commercial landscaping fabric (weed barrier) and about half a yard of ¾-inch crushed gravel.
- Marking: Upside-down marking paint.
Step 1: Choose the Location
Choose a relatively flat spot in your backyard. You need a safe clearance zone of about 6 to 8 feet of open space around the entire perimeter. Keep the area clear of low hanging branches and stay away from property line fences.
Step 2: Call Utility Services
Do not skip this part or you might spend a lot of money later. Before you move any dirt, you need to know what is buried underneath it. In the U.S., simply dial 811 (or visit your local registry, like Arizona 811) a few days before your project. They will come out for free and mark your underground gas, water, and electrical lines.
Step 3: Mark the Hole
Assemble just the top metal ring of your trampoline frame. Lay it on the grass exactly where you want it to go. Take your marking paint and trace the outside edge of the frame directly onto the grass.
Once marked, move the frame out of the way. Take a trenching spade and cut cleanly along that painted line. If you have grass, slice the sod into squares and set them aside—you will use them to patch the edges later.
Step 4: Dig the Shelf and the Bowl
You aren’t just digging a straight cylinder; an in-ground trampoline hole has two distinct levels: an outer shelf and an inner bowl.
- The Outer Shelf: Dig a flat ledge around the entire perimeter. Your metal frame and retaining wall will sit on this ledge. For most kits, this shelf needs to be roughly 10 to 14 inches deep and exactly as wide as the frame. Use your level constantly here—if the shelf is uneven, the trampoline will wobble.
- The Inner Bowl: Inside that shelf, the dirt needs to slope downward into a deeper center bowl to give jumpers clearance. For a standard 14-foot trampoline, the very center of the bowl usually needs to be about 36 inches deep.
A Note on Tough Soil: If you live in the Southwest, you will likely hit caliche—a highly compacted, cement-like soil. Hand shovels won’t do much here. You can rent a breaker-bar attachment for a mini-excavator, or soak the hole with a hose overnight to soften it up before using a heavy steel digging bar.
You can learn more about dealing with this specific soil type here.
Step 5: Install Drainage
You don’t want your new trampoline pit to turn into a pond.
Line the bottom of the excavated bowl with landscaping fabric. This prevents weeds from growing up into the springs while allowing water to pass through. Next, pour a few inches of your crushed gravel into the deepest part of the center bowl. This gives rainwater a spot to pool and slowly absorb into the dirt.
Note: Keep in mind that yards with heavy clay soil might require a dedicated drainage pipe running from the pit to a lower elevation point.
Step 6: Assemble the Frame and Retaining Wall
Put the rest of the metal frame together on the grass. Grab your self tapping screws and secure the retaining wall panels directly to the outside of the frame. Check that all the panels overlap the right way to keep mud from squeezing through the gaps.
With a few helpers, lift the entire frame-and-wall assembly and lower it onto your excavated dirt shelf.
Check your level one last time to ensure it sits flush with the surrounding yard.
Step 7: Install Springs and the Mat
When attaching the jumping mat, don’t just go in a circle. Doing so pulls all the tension to one side, making the last few springs nearly impossible to attach.
Use the clock method instead. Hook a spring at 12 o clock, then do the exact opposite at 6 o clock. Do the same for 3 and 9 o clock. Keep filling in the opposite gaps until the mat is fully secured.
Managing Airflow: Buried trampolines trap a lot of air. If that air has nowhere to go when a jumper lands, the mat gets incredibly stiff. You must secure the vented safety pads included in your kit to let that trapped air push through.
Step 8: Backfill and Level the Yard
There will be a small gap between the outside of your new retaining wall and your yard. Shovel some excavated dirt back into this gap and use a manual dirt tamper (or the heavy end of a shovel) to pack it down tightly. If you leave the dirt loose, the yard might settle unevenly around the trampoline.
Finally, lay those sod squares you saved in Step 3 over the backfilled dirt for a clean, finished look.
Common DIY Installation Mistakes
Even handy homeowners can run into snags. Here are a few common issues to watch out for:
- Digging straight walls: People often dig a straight, cylinder-shaped hole instead of a bowl. This requires moving way more dirt than necessary and makes the retaining wall harder to install. Stick to the bowl shape.
- Underestimating dirt removal: A 14-foot trampoline hole generates a massive amount of loose dirt—often enough to fill the bed of a standard pickup truck three or four times. Have a plan for where this dirt is going before you start digging.
- Uneven leveling: Eyeballing the outer dirt shelf usually results in a frame that sits slightly tilted. Take the extra five minutes to use a laser level or a long 2×4 with a bubble level.
- Smothering the airflow: Sometimes people try to use solid foam safety pads from an old above-ground trampoline. This blocks the airflow and ruins the bounce. Always use vented pads.
DIY vs. Professional Installation
Deciding whether to do it yourself or hire a crew usually comes down to time versus budget.
Tackling it yourself can save you a good chunk of money on labor, and it is a genuinely rewarding weekend project if you enjoy yard work. However, hiring a professional crew means the heavy equipment rentals, the dirt removal, and the exact leveling are all handled for you—usually in a single day.
If you’d rather skip the digging and let an experienced team handle the logistics, you can request a free installation quote from The Jump Shack team here.
Frequently Asked Questions (FAQ)
Can I just bury a regular trampoline without a retaining wall?
You can, but it is generally not recommended. Without a retaining wall, the surrounding dirt will eventually cave in under the trampoline. If you use a regular trampoline, you will need to build your own retaining wall out of treated wood, corrugated metal, or cinder blocks to hold the earth back.
How deep does the hole actually need to be?
It depends on the size of the trampoline. For most standard 14-foot models, the outer shelf is about 10 to 14 inches deep, and the very center of the bowl slopes down to about 36 inches deep. Always check the specific manual that comes with your kit.
What happens when it rains?
If installed correctly with a gravel base, moderate rainwater will simply pool at the bottom of the bowl and slowly seep into the ground. If you live in an area with heavy rainfall or clay-heavy soil, a simple French drain or a small automated sump pump might be necessary.
How do I clean underneath it?
A few times a year, you can simply lift a section of the vented safety pads and use a long-handled grabber or a shop vac to remove any leaves or stray toys that have fallen into the pit.
Ready to get started?
At The Jump Shack, we stock premium DIY kits and offer professional installation services . Browse our online shop today or reach out to our team and get the perfect inground trampoline setup for your backyard.
The Jump Shack
1528 W San Pedro St #4
Gilbert, AZ 85233
Tel: (800) 414-2001
Email: [email protected]
Website: aztrampoline.com
