What kind of roof is a gal alum? Is that a type of metal roof or does this stand for galvanized aluminum? The client called me saying there was a label on the material for this 1960’s home that said cal alum. any insight into what this is?
The term is “Galvalume”. It’s a brand name for a steel-core roofing coated with an alloy of galvanized steel and aluminum. Invented in the early 1970’s, it has become an industry term like “Kleenex” or “Masonite”.
The reason it’s done so well is that it’s pretty durable. Don’t know the lifespan. I guess it depends on the particular product, how it was stored, installed, maintained, etc.