- Most common sheet metal is 29 ga, with a little less in 26 ga (barn roof, siding, etc). Galvalume appears to be galvanized with ZA alloy (55% Al, 45% Zn). 
- Galvalume - last 2x that of galvanized only? . Galvalume regularly lasts 60+ years. . BS alert apparently, as galvalume was introduced only 50 years ago.
- Pro-rib standard at Menards is 29 ga 
- Typical metal brake does 29 ga 
- Van mark $2k - 26 ga