Mr.Verandah suggest the use of iron or polycarbonate for your roof. Both product are available in a number of colours and finishes.
Iron roofing is available in a variety of colours, is corrosion resistant and has superior strength and design flexibility. It is relatively lightweight and requires no long term maintenance.
It can, however, block out a substantial amount of natural light and can make adjoining rooms inside the house darker.
Colourbond carries a 25 year warranty.
Polycarbonate roofing comes in a variety of colours and two main profiles - corrugated and greca. It is highly impact resistant being more than 200 times the strength of glass yet is lightweight and easy to work with. It is an excellent choice if the amount of light coming into the house is important.
The main advantage of polycarbonate is the in-built UV protection layer which cut out almost 99.9% of UV transmission, however UV reduction does not equate to heat reduction. The heat transmitted through standard polycarbonate averages approximately 86-90% with a clear finish, 56-60% with a grey tint and 49-52% with an opal finish.
Ampelite polycarbonate has addressed this problem by bringing out a new product, Solar Control, which will reduce heat transmission to 34%. Ampelite was the first polycarbonate produced in Australia and offers a lifetime warranty.