Have been told black wtaer hose on roof is good option for a ltd bit of hot water. Has anyone any practical experience or links. Need only yield enough for one evening shower. Planning to lay 40m on S facing tile roof wrapped around the double apex so no fixings or weight issues. Main questions is would ground pressure which is fine to 4m existing shower reach another 2 metres higher to the apex If unused for a day or two while away will the water still be hygenic or necessary to flush. Thanks for any advice ,will go for full solar in due course when funding rebuild.