Building a Sunken In-Ground Trampoline A Better Space-Efficient Bounce

Do you want an alternative to traditional trampolines that allows kids to jump with energy and height, but feel put off by their design? If so, consider learning how to build a sunken in-ground trampoline. The benefits of installing this type of trampoline in your yard are numerous, including taking up less space and being easier and cheaper than expected.

The advantages of sinking a trampoline far outweigh the drawbacks, which is why they are typically raised in yards for ease of setup. Additionally, since the likelihood of someone falling off or out of a sunken trampoline is low, there is no need for a safety net.


If you are interested, continue reading. This guide will provide step-by-step instructions on how to build a sunken in-ground trampoline in your yard, regardless of whether it is a 6ft, 8ft, 10ft, 12ft, or 14ft trampoline.

Building A Sunken Trampoline Step By Step

While installing a sunken trampoline may seem straightforward, it requires more than just digging a hole and placing it inside. To ensure maximum safety and enjoyment while bouncing, it is essential to ensure everything is properly fitted.

It’s important to note that you don’t necessarily need a special in-ground trampoline. A regular trampoline can be used, as long as you follow a few steps to ensure it is securely placed in the ground.

1. Check your garden

You’ll be happy to know that you won’t need to apply for planning permission to dig a large hole in your yard. However, you should check if there are any underground pipes or cables in the area you have selected.

2. Mark out the area for the sunken trampoline

The simplest way to ensure the proper fit of your sunken trampoline is to construct the frame first. Then, flip it over so that the rim is on the ground and the supports are pointing upward. Think of it as a giant cookie cutter. Next, mark the entire area around the frame using chalk, paint, or a shovel.

Marking the trampoline hole using the frame.

3. Dig the hole for the trampoline

This will be the space where your trampoline will be placed. It’s important to note that it is not a standard hole. Instead, it consists of an outer hole, ledge, and inner hole.

The outer hole should be around 10-12 inches (25-30cm) deep, depending on the height of your trampoline. The ledge should be flat and 8-12 inches (20-30cm) wide, as it will serve as the resting place for the trampoline supports and retaining wall.

The depth of the inner hole will vary based on the width of your trampoline, why? because it allows you to bounce without hitting the floor.

Round Trampolines
8ft = 30in / 75cm deep
10ft = 30in / 75cm deep
12ft = 35in / 90cm deep
14ft = 35in / 90cm deep
16ft = 40in / 1m deep

Rectangle Trampolines
10ft x 6ft = 30in / 75cm deep
11ft x 8ft = 30in / 75cm deep
14ft x 10ft = 35in / 90cm deep

Below is a diagram illustrating what the sunken trampoline setup should look like:

Sunken In-Ground Trampoline Hole Size

You have two options when it comes to digging the hole for your sunken trampoline: hire a professional or do it yourself.

Hiring a professional may be more expensive, so make sure to get an estimate before starting the work. However, they have the necessary experience and equipment to quickly and efficiently dig the hole. You may be surprised by the amount of labor involved if you decide to do it yourself.

It’s important to hold onto the soil you dig up during the process. If the hole ends up being too big, you can use the soil to fill it back in and bolster the soil around the trampoline structure.

Inner hole in-ground trampoline

4 Check trampoline fits the whole

The next step is to assemble the entire trampoline frame and check if it fits inside the hole you have dug. If it doesn’t fit, you will need to adjust the hole until the frame fits properly.

5 Build a retaining wall

It is crucial to ensure that the inner wall of the hole doesn’t collapse while the trampoline is inside it. Building a retaining wall around the inner hole can help prevent this from happening. This extra work will pay off over time as the retaining wall can save you time and money, as well as extend the lifespan of the trampoline.

There are several options for building the retaining wall, and the method you choose is up to you. For example, corrugated metal sheets can be secured around the inner hole or around the trampoline frame. You can also use flexible plastic attached to the trampoline frame or secured around the inner wall. Alternatively, you may prefer to create a physical block wall around the inner hole.

In-ground trampoline retaining wall
Block wall retaining wall
Plastic retaining wall trampoline
Plastic retaining wall

6. Install weed membrane

Now that you have dug the hole and built the retaining wall, there are only two more steps left to finish creating your sunken in-ground trampoline. It’s time to install weed membrane over the ledge and inner hole to prevent weeds from growing underneath the trampoline.

7. Fit the trampoline into the hole

Congratulations, you have completed all the necessary steps to create your sunken in-ground trampoline! You have dug the hole, built the retaining wall, installed weed membrane, and placed the trampoline into the hole, filling any gaps. Now, it’s time to enjoy some bouncing fun with your kids. It’s exciting to see them jumping around, and you might even be tempted to join in if you’re feeling adventurous!

sunken in ground trampoline