How to make an in ground trampoline and things to consider
When getting ready to put a trampoline in ground there are many things to consider. First is do you have the space? Make sure you leave yourself adequate space around the trampoline should the kids land outside of the jumping area. You should give yourself at least 18ft overhead clearance and 6ft clearance on each side of the trampoline. Make sure you are digging in a safe spot with no gas or electric lines underneath or above.
Next thing to consider is the wall of the trampoline hole. Simply digging the hole will not be good enough because the walls will collapse over time. Make sure there is some type of reinforcement to prevent the wall from collapsing. Most people use a reinforced brick wall, while some will put up a reinforced concrete wall. Some people simply put in wooden walls. It all depends on your budget as to what type of wall you are looking to put up.
Do not forget to put in a drain. This is one of the most important things that people overlook. Without a drain, where will all the rain and drain water go? You will simply have a puddle for mosquito to live and breed in. Not to mention all the mold and mildew that could potentially form. Having all the water underneath will also cause the legs of your trampoline to rust. Also one of the most important things is have a slope for the water to drain into. Create the drain hole in the center of the base. Create the base of your pit with a slight slope elevated higher on the outer perimeter so that water can drain towards the center. This will allow for proper irrigation and prevent any water puddles to form underneath your trampoline.
Make sure there is adequate airspace for your trampoline to breathe; otherwise you will not get optimal jumping performance. There are several ways you can make airspace for your trampoline. The easiest is to elevate your trampoline about 2-3” taller than the wall. This can only be done if you have a wall with reinforcement, otherwise the dirt from a non reinforced wall will simply collapse and fall underneath the trampoline. The second way to create airspace is to have about 6-12” buffer between the trampoline and the wall. So if you have a 12’ trampoline, you should consider digging a hole that is at least 13’ wide.
Before you start digging your hole and getting all the construction started, make sure you buy your trampoline first. Setup your trampoline and get exact measurement. Last thing you want to do is dig your hole and spent time and money on a trampoline that is out of stock or the specs wasn’t what you thought it was. Buy a trampoline that will last a long time. If the trampoline that you purchased was inferior in quality, changing to another trampoline will not be as simple as it seems. The height may be different. Not every trampoline are measured exactly the same diameter. Rule of thumb to consider when selecting your trampoline if you’re not familiar with that company is look for the specs on the frame and the spring count. Having a strong frame with good spring support will ensure the best bounce performance. Most trampoline company will boast about high gauge count. Remember, the higher the gauge number, the thinner the frame. Soft parts can be replaced easily and cheap, but frames are not.
And lastly on safety precaution, just because you are putting your trampoline in ground doesn’t make it danger proof. You should still use the same precaution as you would on any trampoline. Make sure your kids are playing with proper adult supervision and we still recommend putting up a net enclosure. Jumping and falling on the spring mat is a lot softer than falling on grass or concrete.