Sink a trampoline into the ground

Hello everyone,

since we will soon have to commission the earthworks contractor, we would also like to have an excavation done in the garden for a trampoline (flush with the ground) for the children. This circular excavation could ideally later be used for a paddling pool. That means you sink a paddling pool with a metal frame into it.

My question: Has anyone done this before? What should you pay attention to? How should the hole be reinforced? With concrete formwork? Just pour in gravel? Do you need a sewer pipe to the drain? What did the whole thing cost you?

Thanks in advance for your experiences and tips!

Good idea
Such a recessed piece can be found on our playground.
But unfortunately I cannot help further.

Greetings

Hello everyone,

since we will soon have to commission the civil engineer, we would also like to have an excavation done in the garden for a trampoline (ground-level) for the children. Ideally, this circular excavation could later be used for a paddling pool. That means, you embed such a paddling pool with a metal frame into it.

My question: Has anyone done this before? What do you have to watch out for? How should the hole be reinforced? With concrete formwork? Just fill it with gravel? Do you need a wastewater pipe to the sewer? What did it cost you?

Thanks in advance for your experiences and tips!

The problem is that the paddling pool has different dimensions than the trampoline. In my opinion, neither the trampoline nor later the paddling pool is used in a way that such precautions have to be taken. Better to do it "old school".

What should you pay attention to?

The air displaced when jumping must be able to escape. There are special ground trampolines (a brand name would also be "InGround-Trampoline"), whose manufacturers claim that the special frame takes over this function.

In my opinion, no major demands should be placed on the pit, as deep as necessary in the middle, 75 to 100 cm, depending on the trampoline, shallower towards the edges (bowl-shaped). Therefore, in my opinion, no special slope is necessary either. If the soil is reasonably permeable, any water will also be able to seep away. The trampoline itself should be secured/fastened as it would be without a pit.

Then you should also make sure that nobody can slip into the pit at the edge of the trampoline (or only catch their leg between the slope and the edge).

What is the excavator supposed to do anyway? Dig out a basement? Pour a slab? Is the trampoline already there? Do you already live in it? I would possibly not commission the excavator with the trampoline pit but rather create it myself later. Keep in mind that damage may also occur around it (excavator movement, soil compaction, etc.). From personal experience, I would want to keep excavators out of my garden...

There are two variants for recessing a trampoline into the ground.
1. Recessing a regular trampoline with the legs flush with the ground.
2. Installing an inground trampoline.
Both have their advantages and disadvantages.

Regarding 1. It looks good, but:
Higher time and cost expenditure for digging the pit.
Assemble the frame either beside the pit and then lower it in, or assemble it inside the pit if space allows, by connecting the parts.
Tighten the springs while kneeling.
If anything falls in (toys, keys), it is difficult to retrieve.
Animals that fall in cannot get out.
Small children can run onto the trampoline while others are still jumping.
Jumping happens directly onto the ground (higher risk of injury, e.g., ankles).

Regarding 2. Inground trampoline, not quite as spectacular:
It stands about 20-30 cm above the ground.
Only a shallow pit is required, which is easier to make.
For the dimensions of the pit (depending on the manufacturer of the inground trampoline):
Diameter of the trampoline minus 60 cm.
Lowest point at least 1 m below the jumping mat.

Construction:
Excavate the pit to the appropriate depth, provide drainage or soakaway pipe depending on soil conditions, add gravel flush with the surface, possibly with geotextile.
For the flush-mounted variant, shell limestone masonry stones are often used as edging. The diameter of the pit must be correspondingly larger.

To me, it sounds like the civil engineer is coming for the excavation of the house. Then a clear recommendation: wait with the fun until it comes to the outdoor facilities. The civil engineer will have to come back anyway and can take care of it then. Doing it now will hardly bring any benefit.