Hello, I am new to this forum and the gardening world but very keen to do things myself. I've got a lovely blank canvas to start with, so I'm planning to tackle our sloping back garden which is 10m long and 6m wide. I want to build a 2ft high sleeper retaining wall in the middle of the garden behind the manhole as shown in the picture. The idea is to create a flat upper level for relaxing, it'll be turfed with shed on the top right corner. Below are the steps I think I'll follow:
I'm thinking of building a U-shaped retaining wall meeting the gabian wall at the back.
1) Dig a trench for 200mm x 100m sleepers. The bottom sleeper will be halfway underneath the ground.
2) Lay the bottom sleeper course on compacted gravel base. Should I put a rebar through or lay them on concrete mix for fixing them in?
3) The rest of the courses to be laid with staggered joints (brickwork style) and screwed with stainless steel screws.
4) The back of the wall covered with dpm and backfilled with 20mm gravel for drainage. Do I need to install a french drain pipe too for drainage? It's heavy clay subsoil under the top 100mm of topsoil.
5) To prevent the brickwall on the left & fence on the right from damp/rot, I'm thinking of leaving a 100mm gap between the wall/fence and the side of the retaining wall & cover that gap with some gravel. Will that be ok? I'm open to suggestions for protecting the side walls..
Apologies for the long post, I just want to make sure I've covered everything before I start this project. Appreciate your time reading this and looking forward to your views opinions on dealing with the slope. Feel free to highlight anything I'm missing.
Attached 1st image of the land as it is now and 2nd is a computerised image of how I visualise it with the retaining wall. Please note that I didn't put the u-shaped retaining wall in the image. It's just something I thought of today while thinking on how to protect the wall/fence from raised soil contact.
Appreciate your time and thoughts....
