Meccano

Hope you don’t mind me resurrecting this thread but I’m looking for opinions on an alternative my architect has suggested – something called ‘Modified Bituminous Asphalt’.
Has anyone got any experience of this system? Has it been used widely in Ireland? Difficult/Easy to install? Price?

I was originally thinking about a Zinc roof on my building too (this is a house with a 45 ft span) and all my previous experience with any kind of asphalt roof has been horrible. They leak, they deteriorate, and they look ugly!:(