Home DIY

We want an outdoor shower in the back garden. Any flaws in this plan?

1. We have an outdoor tap already;
   
2. Fit y-piece. One to hosepipe, one to new shower;
   
3. Flexi hose from y-piece to copper piping;
   
4. Run copper piping along external wall (brackets every 1m into brickwork), just above ground level to avoid patio door step;
   
5. 90deg bend to vertical and run copper pipe up the external wall to desired height;
   
6. Possibly include additional valve in this vertical section; and
   90deg bend back to horizontal, to allow showerhead fitment.
   
   

Put a slight fall on the first horizontal pipe, back towards the tap, so the flexi hose can be unscrewed and the system emptied over winter?