It's always interesting to hear about building codes and methods in different parts of the world, things that make sense in Australia just don't in Canada, Europe or parts of the US.
Earlier on I think Darren assumed, as did I that you would just use a flat roof construction, in Australia it just would never cross one's mind to use anything but a flat roof on this sort of building, when I first came to the UK I was talking to a roofer, about a building that we were involved with planning, we had done three of them in Oz and the plan was to do another here, in Oz we had already had twelve years out of the first one and it still looked like new but the roofer kept saying "oh, yeah you can use that $%^& if you want to but it'll rust through in a couple of years, so I questioned a little further and soon realised that what we know as sheet steel roofing varies wildly across the world as does the climate and the painted steel sheet I had specified wasn't Gavanised under the paint and the extra condensation under the sheet due to the snow cover and more extreme cold (not really extreme only snow for a week or so a year) would have readily attacked the areas where the paint was cracked due to the screw holes.
In short when you travel take note of what the locals do no matter how good you think you are.
Locally to me now, we have a lot of thatched cottages and that is one type of roofing that always amazes me, It wouldn't last five minutes in Oz, reeds tied down with string, where I grew up it would almost guarantee your house burning down each year due to bush fires, both the natural kind and the arsonists would mean a load of insurance claims.
But they are just so dern purdy those little storybook cottages, with Cob walls or Tudor "ship beam" contruction, where I grew up Tudor Styled meant asbestos sheeted bungalows with dark brown painted strips of timber tacked on covering the joins
I lived in a Hotel in Sussex for about six months in the mid 2000s (Naughties?) it was about five hundred years old and was all built out of old naval ship timbers apparently, the ridgeline dipped about 18 inches in the middle and all the walls were bellied one way or another, it looked like something out of the Lord of the Rings movies, but I have no doubt it'll be there in another five hundred years, at about the same time a friend in Oz was buying a house and the surveyors report made a huge fuss over one of the walls being out of square and the ridgeline dipping an inch or two, I have no doubt that this was serious given the construction methods used but the contrast was stark and has stayed with me.
Sorry to hijack the thread, babbling on about this, but it is of interest to me so I figure maybe so to others as well.
Best Regards
Rick
Whatever it is, do it today, Tomorrow may not be an option and regret outlasts fatigue.