Hawk, this isn't the same stuff that is in Home Depot. 5V is the designation for that particular crimp pattern. I'm pretty sure that the stuff they are trying to sell me is steel with a baked on paint. But am still waiting on the specifics. It does look like a shed roof however.
I understand that. I suggested Home Depot or Lowe's as a way to get a sense of the metal thickness before buying and crying.
As it happens, I just came back from a trip to Lowe's and, with this thread in mind, I stopped by the miscellaneous metal rack to look at the steel sheets. I would say 26-gauge is probably minimally acceptable, although I doubt very much that it would resist denting from hail. 29-gauge, IMHO, is too thin to even consider, except for a shed or outbuilding.
If I were doing a metal roof, I'd go for one of the fake standing seam roofs with the concealed hold-down clips. The system you're looking at uses exposed screws with rubber washers to seal the holes. The roof panels may last for 25 or 40 years, but you can be sure the rubber gaskets won't.
If you are considering putting the metal directly over the existing shingle roof, be sure you know what's already there. The building code that's used just about everywhere in the country prohibits more than two layers of roofing. If you already have two layers, at least one will have to come off before the new roof can be installed.
