How to create a sunken trampoline

I think a sunken trampoline has to be my favourite family garden feature. It's a simple enough idea but solves so many headaches. It's safer, less intrusive and popular with everyone. 

I have sunken a couple myself. Well, to be more accurate, I've sunken the same one twice (note to self - decide where to put the thing and don't change your mind after 12 months). And I have also designed several gardens with sunken trampolines, so I now consider myself, if not an expert, certainly au fait with the ups and downs (no pun intended).

So what do you do...?

• First, measure up - I would say buy a relatively large trampoline (ours is 14') but make sure that it won't dominate the garden.  Also, when measuring up, remember to leave at least another 50cm all round for the doughnut (don't worry, I'll come to that later)
• Purchase your trampoline - these are easy enough to buy online and I personally don't think there's a massive difference between the brands.  What is worth looking at is shape and weight limits.  You might think the trampoline will be used by the kids, but you'd be wrong - adults are at least as likely to want a bounce (and in my experience, more likely to injure themselves, but that's another story).  So, get one that will take up to 20 stone. (NB For some more information on costs/relative value of this and other garden play equipment, check out this post)
• Choose the shape and colour - mine's round, because it suits my garden shape, but I've also used rectangular ones to fit into clients' gardens with a more formal layout. Also - don't forget to order green padding at the side (khaki if they offer it) as it's less jarring than bright blue
• Mark out the size of the trampoline - I have an old screwdriver I place through the end of my tape measure - stick this in the ground, hold a can of spraymark, and run round in a circle, spraying (just watch your shoes). If it's a rectangle, try to use a builders square to make sure you are accurate, or simply place your trampoline upside down in the ground and mark round it.
• Get digging - OK, you can cheat and get in a man with a digger, but this is likely to cost around £300 so if you're on a budget or need the exercise, do it yourself.
• Topsoil good, subsoil bad - Remember, the first foot or so is likely to be topsoil and should be kept to one side.  Below this is subsoil - and if you can, I would suggest this is taken off site, or buried somewhere below topsoil.  You can see the difference quite easily as you dig down. If you’re digging it yourself, allow a weekend and consider getting in some help as it's pretty hard work, especially when you get further down and the soil's more compacted.
• Drainage - If you've got a high water table or bad drainage, I would suggest you make a mini sump in the central area by digging down an extra foot and filling with rubble or pea shingle.
• What depth? - I've seen advice which says; leave the trampoline sitting 2 inches above the ground to allow air to escape.  Personally, I don't do this.  I've not found the air flow an issue unless it's been raining which covers the micro-holes in the trampoline surface and stops effective bouncing, but this is rare.  Also, if you sink it flush to the ground, it stops things falling under the trampoline, negates a trip hazard and makes it easier to mow around.
• Use top soil to form a doughnut - I put a foot high, double sloped and flat-topped edge round the area which disguises the trampoline from a distance.  The children also love running down this onto the trampoline
• Turf the area - this helps make a neat finish and you can fold it over at the edges if you need to fill in any holes

And that's it, except to say, sunken trampolines might be safer, but not so safe that you shouldn't supervise very carefully.  However, they do make it easier for all ages to enjoy - my son was happily bottom-bouncing on the trampoline before he could walk and even Eric the cat enjoys a stroll over the surface to put a spring in his step.

Oh and if you want to see a couple of films about putting in sunken trampoines and how to maintain them, check these out below:

 

 

 

Comments

[misty gebhart]

how deap did you dig your hole?

[Dawn Isaac]

TypePad HTML EmailJust the depth of the trampoline legs - about 90cm

[Tricia]

Did you line the hole to keep it from caving in?

[Dawn/LittleGreenFingers]

Hi Tricia - no, it had enough clay content to hold itself in place - subsoil is also a lot less 'crumbly' than topsoil so in most land it should be OK.

[Stephanie]

What happens to rain water that collects below the trampoline in the hole? Is that an issue? This is such a great idea, but I'm just wondering about water drainage??

[Dawn]

HI Stephanie - we don;t have a problem with this but it depends on the height of your water table as well as the profile of your soil. I woulf suggest digging a very small trial hole and seeing what happens. If you have a high water table and the hole keeps filling up I wouldn't even think about sinking a trompoline. If it's a very minor issue, I would add a sump (as described above in 'Drainage')

[Shanda]

I always thought this was a great idea until a little boy around here nearly drowned in a sunken trampoline hole. Here's the link to the news story: http://tinyurl.com/6sm62dj. So sad.

[Shanda]

Oops, the link doesn't work. Try this: http://www.woodtv.com/dpp/news/local/central_mich/child-falls-in-trampoline-hole

[Emily]

So glad to have seen this link! I have always wanted to do this and wasn't sure how to tackle it. Thank you so much!

[Jen]

To Shanda-
That trampoline from the accident you posted had a gap big enough to fit an adult! If you plan to "sink" it then sink it. Don't leave any space....that's just common sense!

[Terri]

Do you take it out of the hole during winter? If not, do you cover it with something?

[Dawn]

Hi Terri - I have left it in the ground for the last three years with no cover at all. No problems to date!

[samantha]

Do u know if this would work for me, we live n Alabama with the red clay? I want this so bad for my kids thanks

[Dawn]

Hi Samantha - clay soil or high water levels are the biggest problems. Clay can be so impermeable that waterlogging could become a problem. Best thing is to dig a small trial hole and see what happens (but, remember, if it does fill up with water it can be a massive danger to the children so take precautions). A sump at the base of the hole can help but I would certainly proceed with caution.

[Atlantic Trampolines]

If you have to line the hole to stop it caving in you can get a specialist system to do this from trampolinesdownunder.com. Also if you want to improve the air flow under the trampoline you can install some lengths of 4" flexible pipe by burying one end just under the surface of the hole to a point some distance from the trampoline on ground level. This also makes a fun feature for children to play with as the air blows out and sucks back in. Give us a call if you need help with any aspect of sourcing a trampoline. Our advice is free from our team of trampoline supply experts.

[trampoline pads]

Hence happy to have found this link! Concerning always wanted to do this and wasn't sure how to tackle it. Many thanks so much!

[A. R. G.]

great idea! can you tell us about the tubular framed folly in the background. please? is it a kit? diy? what is it used for, if you don't mind?

[CandiL]

I really would like to try to do this...but you forgot to mention how deep you dig the hole.

[Michael Anthony]

Where is the protective netting?