Thread: Build a hidden, suspended sandpit - help

Hi, I'd build up the bottom of the box with sleepers, I think they're 200mm wide these days, say 3 high, fill 2 high with blue metal or similar stone diameter for drainage and the rest with sand. As for keeping it dry, I'm out of ideas, maybe perspex screwed to the underside of the decking lid, dunno, I'm sure there'll be better ideas coming but what ever you do think about being able to secure the lid from falling on the little chickadees

I agree with Springwater, build up from ground level. You definitely don't want to suspend this from the deck, given that you'll have to cut joists and/or bearers. Wet sand is very heavy. And I wouldn't hinge the lid, make it totally removable - less chance of fingers getting caught. As for waterproofing - a rubber tarp/mat fitted under the lid should do.

Thanks for the replies, it makes sense to build it up from the floor.

So if I was to make a hole in the deck, given that I'll have to cut some of the support structures, will I have to do something here to sure it up do you think? ie, add some new support posts or something?

Thanks

where ever you cut a joist you will have to place a support post , or you will have issues.

To water proof . I would use pond liner , not pvc, and it will need some angle so that the water will run off and not pool in the sections between the flooring supports.

It would be nice to have a lift off lid, but what will it weigh??? a hinged lid with a couple of catches to hold it open , would be better, Catches above child's reach.

Jeff