I have a project in mosman park which requires a colourbond auto garage door. The width is 4500mm. The height at the opening is 2210mm and at the middle purlin of the carport it drops to 2160mm. I need to maintain maximum height insdie the carport. Can you provide me with an estim,ate for a suitable door and how much we would loose at the front and middle Beam/purlins. Thank you. I am available by telephone.