FAQ
What size and shape of trampoline does the system work for?
The TDU retaining wall system was designed to be able to accommodate any ROUND trampoline Size. The standard kit is 33 interlocking panels, for a 14ft. Trampoline. The kit comes with self tapping screws to mount the kit to your trampoline.
If you have a smaller or larger round trampoline, please specify when ordering as we can send you fewer or additional panels depending on the size. Due to the design of the interlocking system, it will not work for OCTAGON or RECTANGLE trampolines.
Does the kit come with a trampoline
No it does not. But we recommend a well built trampoline, and suggest that you stay clear of a cheaper light weight trampoline. When putting a trampoline in the ground there is added stress on the frame, and therefore those with weaker frames tend to lose shape and have problems early on. We do carry trampolines as well that we recommend, but they are only available to local customers.
Will the TDU System work with a trampoline that has a Safety Net Enclosure?
Because most Safety net enclosures attach to the trampoline on the outside of the frame, this gets in the way of the TDU Retaining wall kit which also attaches to the outside of the trampoline frame. Some nets will attach on the inside of the frame which would work with our system. We have had homeowners take a dremel tool or a saw and cut the TDU kit at the areas where the Safety Net attaches on the outside, and this works well, but unfortunately we cannot offer a full warranty if this procedure is done.
What is the warranty like?
The TDU retaining wall system was engineered and designed for its specific purpose. If installed correctly the TDU system will outlast your trampoline. We will replace any damaged panels within the first 10 years at no cost if it can be determined that the system was properly installed. (excluding damage from severe acts of nature)
Does putting a trampoline in ground reduce the bounce?
One of the most common concerns of putting a trampoline in the ground is losing bounce quality. There are a few factors that play into this theory.. 1st the quality of the trampoline. A cheaper trampoline, with a poor quality mat, and lower spring count will not bounce as good as a better built trampoline, and will be even more noticeable when placed in the ground with air not being able to escape. The 2nd factor is how tight the Safety pad is installed�If the pad is tied down as tight as possible this also prevents air from escaping as easily. Make sure you are getting a quality trampoline, with a higher spring count, and the bounce quality will be similar to that of an above ground trampoline.
Can I install the trampoline slightly above Ground?
The TDU Retaining wall system needs to attach to the top ring of the trampoline for support, so you cannot install the trampoline above the kit for air flow. You can however leave the kit and trampoline above grade a few inches if you would prefer to have a better edging surface, so to not destroy your safety pad with your edger. Trampolines Down Under recommends installing the Trampoline at Ground level to help prevent injury.
Should I put gravel in the bottom of the pit?
Depending on your local soil conditions, it is usually recommended to use both dirt and gravel for your backfilling on the inside of the Trampoline Pit. Gravel will create a sump effect that will help prevent standing water.
What do I do about drainage issues?
Depending on local soil conditions, and the grade and location of the Trampoline Pit in your yard you may need to consider additional drainage solutions. In some cases we have suggested a French drain in the center of the pit, and in severe water circumstances an electric sump pump that could pump the water to the surface of the yard as needed.
How do I level my trampoline to prevent it from sinking once it's placed in the ground?
Depending on soil conditions, and the climate you live in we recommend a few tips that can help. If you have a very soft clay based soil, we recommend using some block or compactable road base below each of the four legs on your trampoline- this will help prevent the legs from sinking into the ground.
When installing the trampoline into the ground, an easy way to ensure the trampoline is level (if you do not have a laser level) Is getting a 12ft 2x4 and setting it at an angle across the top bar at each leg angle. Then place a Level on the 2x4 and adjust accordingly. Do this at 4 different angles around the trampoline to ensure it is properly level PRIOR to backfilling the inside of the trampoline.
How many people does it take to install the kit onto my trampoline?
It can be done with one person, but at least two people are recommended. The instructions show to raise the system up to the trampoline top ring, but it is easier (if you only have 1 or two people) to set up the trampoline frame, then the kit around the trampoline, then rather than raising the kit to the ring, remove two legs and drop the Trampoline top ring down to the level of the kit. Place a few screws then take off the other two legs and drop the Trampoline frame on that side and place a few screws. Then put the legs back in and set the remainder of the screws one per panel.
How Big is the TDU System?
A 14ft TDU Retaining wall system comes in 3 boxes (28x20x7.5") Each box weighs 45lbs. The kit costs $65.00 to ship, and can be picked up locally or at our dealers in the Trunk of most automobiles.
Backfilling on the Inside of the Pit
The video shows to backfill the inside of the pit half way up the TDU panels. This is done to create additional strength for the light weight panels, and to keep them from collapsing under pressure of backfilling on the outside. Dirt or Gravel should be used to backfill above the backfill point on the inside of the panels (8 horizontal lines across the center of the panel) This dirt/gravel should be compacted against the panels and should start to slope immediately towards the center of the hole. You should have at least 3ft of clearance between the bottom of the pit and the jumping mat. As long as the dirt begins to slope towards the center within 12" of the panel, you will not have any problems hitting dirt on the sides as you bounce.
Keep in mind that if you exceed your trampolines suggested jumping weight limit, you could potentially hit dirt below. (this can happen to a trampoline above ground as well- so be sure to follow the recommended jumping weight limits of your trampoline)
What are the advantages of using the TDU System over other retaining wall methods?
The TDU Retaining wall system is the ONLY patented Ground level trampoline system in the industry! There are other "methods" that can work but are more labor intensive, more expensive and they all have draw backs to using them.. here are a few of the attempted methods in the industry and why they are not as effective.
Corrugated Metal Sheets
Many contractors have used 4 large sheets of corrugated metal and attempt to bend them and bolt them together to create a circle.. this works well to retain the dirt, but the issue is creating a perfect circle that fits the exact diameter of your trampoline. Usually there will be gaps which will allow kids shoes, and toys to fall into the pit, metal rusts, and if the trampoline happens to sink slightly, it will expose the metal edge of the metal ring and kids can cut their feet on the sharp edges. (not to mention the metal sheets weigh 800 lbs and are 8ft long each- usually requiring a trailer to haul them to your home).
Pressure-Treated Rail Road Timbers
This works well for rectangle or octagon trampolines, but for round trampolines creates gaps around the circle, the wood will eventually rot, and there is a 4-6 inch hard surface surrounding the trampoline that the kids can fall on and hurt themselves. Very labor intensive, and cost of materials can get very pricey.
Concrete block, or pavers
Again, this method is more labor intensive, and creates a hard surface that surrounds the trampoline that the kids could potentially fall on and hurt themselves.
Chicken Wire
Although we have seen this done many times, THIS WILL NOT WORK. We have sold many kits to homeowners who first tried chicken wire to retain the dirt, only to find that chicken wire was only meant to hold in chickens
