Finding the right metal guttering can be a challenge. Strong metals will rust while lighter weight corrosion resistant metals have difficulty standing up to the forces of nature. So, what is Galvalume? Galvanized gutters are the best hybrid seamless rain gutter choice. Galvalume is a composite of sorts with a substrate of steel and a coating comprised of both aluminum and zinc making Galvalume steel gutters top tier and perfect against any weather Michigan can throw at them.