NWalch wrote:
I've created raise beds using railway sleepers and want to fix pond
liner round the sides before I back fill with soil. Can anyone
suggest
the best way to fix the liner so that the top is sealed to prevent
soil getting down the top.

.... 'Not sure what the purpose of the pond liner is.

Is it to protect the sleepers?
We have a railway sleeper bridge over a roadside ditch that was
constructed at least thirty years ago. It was covered with a foot of
soil and is grassed over. Tractors drive over it. I think the sleepers
will survive on their own without the liner.

Is it to protect your delicate plants from the nasty wood
preservative?
Once the sleeper has 'weathered' or aged, so that the preservative is
not freshly active, you will have no problems. Ivy and other climbers
happily climb up treated telegraph poles. True, plant roots close to
the sleeper may be persuaded to grow away from it, but the
preservative will not leach out into the soil.

--
ned