which type metal roofing to buy

You will need to known the pitch of your roof and select a metal roof suitable for that pitch. Insulation is an option under some products. Oftentimes the old shingles are left in place, due to the low weight and design of metal roofing

I am on a committee advising our church Board of Trustees on replacing 65 squares of asphalt shingles over our 160 year old National Historic Registered sanctuary near the coast of Maine. The timber framed roof is a 9 in 12 pitch. The benefits of light weight and 40 - 60 year life make a metal roof of simulated architectural grade shingles appealing because the embedded grit in the surface finish will hold snow packs as well as asphalt, an issue in our climate with walkways under the roof eaves. A church inland from us has just replaced theirs with this type metal roof. However, we have been told that because our church property, while miles from the ocean, fronts a saltwater estuary of a river, a warranty for the expected service life will be doubtful or more restricted. Is zinc or aluminum ever used in lieu of steel? What are the manufacturers? Is the zinc plating described in this site sufficiently tough to withstand occasional Nor'easter storms that could drive salt spray on to and under this roofing?

Many of the metal panel systems incorporate a zinc coating in addition to their paint finish. Best thing to do is to figure on a look that you like and contact the manufacturer as it pertains to their warranty. Check with the MRA for participating vendors that do a stamped shingle pattern.