"material was specked in for us by an architect" .... Assuming the architect 'knows' his/her stuff by experience and knows indeed that it works, in your particular instance, was it installed right, for example, slate and shingles work on pitched roofs, but if not installed right...warrantly is voided

We have a seamless flat metal roof. We are happy with it. It's not rusting so i'm thinking it's aluminum...i can use a magnet to confirm if aluminum or steel, but i'm thinking its steel with a baked on finish. The drawback was it is held down with screws, and around the screw heads a small amount of rain water seeped in and created very very minor water spots on interior walls. We covered those screw heads with silicone. One year later...so far so good.