Galvalume is sheet steel coated with an alloy of aluminum and zinc. It is more corrosion resistant than galvanized steel but it doesnÂt self-protect scratches or cut edges nearly as well and it is also more susceptible to staining from corrosion at tight bends (tension bend staining) so it is used most commonly in simple profiles like standing seam roofing. Galvalume steel is very shiny so although it is sometimes installed unpainted, it is usually painted on a house. It must be cut with a shearing action rather than saw-cut. If the porch roof slopes are low you might consider running the metal roofing up the main roof a foot or two in order to protect that intersection. There are other precautions depending on your climate.

IMO these are questions that should be asked of your contractors during the interview process. They could more accurately answer your questions about the harness situation if they were standing there looking at the home. I had a metal roof installed last year and yes, there were options for the edges. My underlayment was a titanium synthetic and varying grades were available. Every contractor is different- answers you receive here may not always be the same answers you would get from a local guy looking at your house. Call guys, get estimates, ask questions! It is free. This part of the process can be very educational if you approach it as such. Every topic you discuss in person with an expert who is literally looking at your roof leads to more topics and more understanding of the process. Between contractors interviews and further more specific research as you get deeper into the process, by the time you sign your contract you should have a very clear understanding of the hows and whys as they pertain to your individual situation.

Our framer is beginning any day on our new construction near the boundary of zones 4 and 5 in Illinois. After feedback from Sanford, GreenDesigns, Sophie Wheeler, and JDS, we are looking into switching our standing seam metal roof to an EPDM roof. Our elevations with 1:12 pitch roof are shown below: I had done a lot of research on the proper way to construct, ventilate, and insulate our standing seam metal roof. This sketch is what we were thinking: Will a similar cross section also apply to an EPDM roof - only replacing the metal roof with EPDM? Is the EPDM adhered directly to the OSB/plywood sheathing? Any considerations for EPDM that I should discuss with our builder?

and Zahner Zinc could possibly stamp out some custom metal roofing if your roof pitch is steep enough. Or a decent sheet metal shop can bend up sheets of aluminum and do flat lock similar to millenium but in larger pieces. It's hard to get good installation with metal. They like to use a lot of caulk joints, which defeats the purpose The aluminum standing seam they keep telling you're thinking of is "Galvalume" style which is steel electro plated with aluminum somehow. Galvalume is still "ferrous" and would rot by the ocean if it found a good galvanitic reaction with something. What you meant in your title was "non-ferrous" . If you have a roof made from stainless or a non-ferrous metals like zinc, copper, aluminum, and it looks correct to someone who knows, there is no guessing as to how long it will last undisturbed.