can anyone think of a genius way of repairing our sand pit?

[HeadFairy]

We inherited a sand pit in our garden, it's made using railway sleepers to form a square 65cm x 65cm and 20cm deep. It's currently lined with what looks like pond liner but it's badly torn with roots coming through. I would replace the pond liner and put clean sand in, but I don't think the pond liner is the best way of lining it... the roots of a nearby tree keep poking through.

My mum suggested buying a plastic box to fit inside but I can't seem to find one. Does anyone know where I can get something like that, or else think of a better solution please?

hmm i would use pond liner myself. you can get really fairly thick stuff. or a tarpaulin or something.

how high up do the roots poke up? you could always put a hefty layer of sand in around the roots to buffer the pond liner? so they don't stick up as far?

alternatively, could you shift the hole away from the tree?

I can't move the sand pit because it's part of a raised bed, the railway sleepers form part of the raised bed too.

The pond liner that's already there does seem really thick, and still some roots managed to make their way through, but I don't know how long it's been there, it could have been forever, so the roots had plenty of time to get through the pond liner.

The roots that came up were little offshoot type roots... they weren't big ones, but they poked a hole in the pond liner...

Could you put some flat plastic down at the bottom of it then the pond liner on top. THat way you are only needing to cut a piece of plastic to fit the base and not needing to find a box to fit.

tbh i think tree roots will go through anything. they can force their way through tarmac and concrete!

the kids won't jmind a few roots being in there, and as long as there is plenty of sand it'll be fine

i'd replace the pond liner (or investigate a thicker liner - but pond liner is pretty tough) but dig down a bit once i'd taken out the old one and cut the tree roots right back. Pond liner isn't too expensive and it wouldn't be an enormous job i don't think...could you line the base of the sandpit with some old carpet too, just to slow up the progress of the roots?

How about a huge bagful of pebbles over the roots with 2 layers of tarpaulin over the top?

These are all great ideas thanks! I guess I'm going to have to try and source something to put underneath the pond liner to slow the progress of the roots... you're right thisisyesterday, ds has already been playing in it and it's filthy in there, and full of building sand. I'm going to replace the liner and fill it with play sand for him. It's quite a big job so I do want to do something that'll last as long as possible.

actually, the only other thing i can think of tha might work is on the side/s where the roots are, to get some sheets of metal and push them right down into the ground, flush with the sides of the pit iyswim?

that's a good idea... I'm going to have a good rummage around B&Q to find something. We've got some cement in the shed too, I know the roots will eventually get through it but it'll all help I guess.

Now I've just got to work out how I seal the pond liner at the top of the sand pit. I assume I can buy something that seals it to the sides of the pit so the roots can't just push up through the gaps at the top.