We have a tiny alleyway to the side of our house (slighly less than 1m wide) that would be ideal for storing our bikes if we could keep them dry and secure. We have a wooden shiplap fence with concrete posts to one side and a flat, rendered wall to the other. There is already a wooden gate to the front so the plan is to build a little wall to the back and a lean-to roof over the top to allow us to keep bikes inside without having to further lock them up - about 2-3m long at the most. Looking for advice on how to build the roof - particularly on how to attach it to the house wall and to the fence. This doesn't have to be anything spectacular - I doubt we'll live in this house for more that another few years, so I just need something very simple. I understand how to build the roof structure but not sure if we need to add flashing along the house side? Also, can we build a board roof with felt like a shed or would corrugated polycarbonate be better (I don't need any light and security is more of an issue). With regard to the fence side, we can't sink more posts very easily due to the narrow space and because the alleyway has a concrete floor which acts as a retaining wall and sits a good 50cm above the road to the other side, so really it will have to sit on the top of the fence posts, though we can add timber to the sides of the posts. Any advice greatly appreciated.