Retaining Wall advice
Hello, I am fairly new to this forum and received great help & suggestions to my first post. So, I'll summarise my plan here:
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, it'll be turfed & planning to keep the shed in the top right corner. Below are the steps I think I'll follow, please share your thoughts, opinions, issues or anything I'm missing:
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) Line the inside of the retaining wall with membrane and backfill with gravel to avoid soil contact and help drainage. Would that be enough or do I need to install french drain pipe as well?
5) To prevent the brick wall on the left and fence on the right from damp/rot, I'm thinking of building a u-shaped retaining wall keeping it flush with the gabion at the back. I plan to leave a gap of about 100mm between the brick wall/fence and retaining wall and put some gravel in that gap to make it look tidy. Is it a good of doing it? Open to suggestions on this.
I've attached a couple of pictures - 1st of the land as it is now and 2nd a computerised image (created kindly by someone in this forum) of how I visualise it to be. Please note computerised image doesn't show the u-shaped retaining wall yet as it's something I only thought of last night.
Please share your views on this and any issues you think I need to be aware of. Thank you for your time and invaluable advice & apologies for the long post.