Raised 3 sided sleeper bed against concrete retaining wall

[Chelseajade]

Hi everyone, I'm planning on constructing a raised sleeper bed (900mm width

x 6300mm length x 400mm height - 2 sleepers high). I have a retaining wall at the side and back of my garden made of concrete that I was planning on attaching the sleeper too instead of using 4 sides. The retaining wall is a geowall and is attached deep into the ground with only soil behind so I'm not worried about damp. My only worry is securing the bed to the concrete and the stability of only having 3 sides with the weight of them filled. Please can anyone advise if I can get away with only having 3 sides and if so, how should I attach this? Thanks in advance

 

[oakysmokyjoky]

Hi. is this for flower/veggie bed with soil in or something else? So long as you attach the sleepers to each other I can't see this shifting position as there's not a great deal of horizontal force. But, based on our experience with rotting sleepers I'd be more concerned about getting use class 4 for pressure treated softwood, treating cut ends with proper stuff and minimising screw holes (which interferes with proper fixing suggestion). Also are you lining the sleepers? Sometimes that's good or bad! If you were to sue recycled plastic sleepers you wouldn't have any of these issues but they are extremely heavy.