Sandpit advice - sunken pit with clay soil

[John74813]

Hi all

I'd like some advice please regarding the feasibility of a sandpit in this space. The garden was landscaped by the previous occupants and they had a trampoline in this pit. I've deemed it personally to be too unsafe having a trampoline this near the fence and wondered about the practicalities of turning it into a giant sandpit instead.

I have a couple of questions.

Firstly, will I cause any damage (rotting?!) to the retaining timber by partially filling the pit with sand?

If not, then my next question is around drainage. The soil underneath is clay. As the pit is already quite deep would an option be to fill it with a couple of inches of gravel, followed by weed membrane and then the sand?

Lastly, I'd need some sort of cover for it to prevent leaves/twigs from the oak tree above from falling in. I'm thinking of some kind of retractable netting that can be pulled over (and off) easily. Netting to allow for moisture to escape from the sand rather than a solid cover. Is this a good idea or is there something I haven't thought of?

Thanks very much in advance for your help and suggestions

 

[freddiemercurystwin]

Why not just fit a safety net?

 

[John74813]

Why not just fit a safety net?

For the trampoline? I've been doing research and even with a safety net, it's not advised to have it this close to a fence. As well as this, the retaining wall at the back will be higher than the trampoline base so any one "falling" into the net would still hit (albeit, through the net) the wall. The same can be said for the fence.