My contractor is about 80% through building a garage / apartment on my country property (30 X 42 ft, 2 story, 35 feet high, with 2 nine foot high doors for my tractor and boat bays). Such will have a coated aluminum roof, and the lightening protection stuff seems reasonable (done by a lightening protection subcontractor). There are rods along the apex of the roof every 6 feet or so, connected to each other in the attic with what appears to be 3/4" thick and loosely braided copper wiring. The wiring connects to grounds (8 foot in ground stakes) on each end of the dwelling, with the copper wire inside conduits going down those 2 sides of the dwelling. What else - hmm - surge arrestors on the main electrical line in and on the phone line. Despite all of the above, I will have lightening damage insurance, along with usual flood, etc. - I, like prior posts, may think the system, installed by professionals, will work, but I'm not certain, and I've seen what a lightening strike can do to a house.