I'll try without stakes for the time as there will only be bark chippings in there. read a few other posts and some people lay them on shingle to stop them sitting on water. Also some staple a waterproof layer to the bottom.
I've just bought 8 new brown treated garden sleepers (2.4m x 125 x 250) with the intention of creating an enclosure around a trampoline area. I have a membrane and bags of woodchip to cover the area and 200mm timberlok bolts to secure the sleepers together.
My question is hwo should I...