On 5/9/2016 8:29 AM, Chris French wrote:
Wrote in message:
I'm planning an extension to my house, and want to make flat roof that will last a long time, is maintenance-free and tough enough for people to walk around on, and is fairly light in colour on the surface.


When you say walk around on, do you mean occasionally for access,
or for regular use?


That's the key question. Other options to those already listed are
fibreglass, lead, and zinc.