Yesterday a roofer was here and, when asked about a metal covering for the porch roof, said: "challenging, but of course doable." He suggested covering the entire area (except for the gable edge) with one sheet, which means the sheet will have a solder seam because roofer sheets are only up to 1 x 3 meters in size. Since a soft-soldered seam does not hold securely at that size, he advises hard soldering (which I can hardly believe is possible, but that is how I understood him). Then copper would probably be the most suitable material. At the lower edge, the sheet would extend 2 to 3 centimeters over and would have to be bent slightly downwards so that water is not drawn back up on the underside - between the wood and the sheet - by capillary forces. I am still happily occupied with it. Corona times are great for my considerations. I have time and no pressure to deliver results quickly. In the meantime, I have already built many models and pondered various options...