If you’re planning a street lighting project, you’ve probably come across the debate between Galvanized Iron (GI) and ZAM coating for steel poles. Both have their merits, but understanding the differences can save you headaches and money down the road.

What’s the deal with GI?

GI poles have been around forever, and there’s a reason for that. The hot-dip galvanization process coats steel with zinc, creating a protective shield against rust and corrosion. In most environments, you’re looking at a solid 15-25 years of service life. In addition, GI is everywhere, competitively priced, and your contractors know how to work with it.

The catch? If you’re near the coast or in an area with heavy pollution, that zinc coating breaks down much faster. You’ll find yourself dealing with maintenance issues sooner than you’d like.

Enter ZAM: THE NEW KID ON THE BLOCK!

ZAM coating is basically GI’s smarter cousin. By mixing zinc with aluminum and magnesium, manufacturers have created something remarkable. The aluminum acts like a heat-resistant barrier, while the magnesium gives the coating this almost magical ability to heal small scratches on its own.

The numbers speak for themselves. ZAM can last 30-40 years and resists corrosion three to six times better than traditional GI. That’s a game-changer for harsh environments.

So, which one should you choose?

Honestly, ZAM costs about 15-30% more upfront. But if you’re installing poles near the ocean, in industrial areas, or anywhere with tough weather, you’ll make that money back through fewer replacements and less maintenance.

For inland projects with tight budgets and moderate conditions, GI still makes perfect sense. But more and more cities are switching to ZAM because when you look at the total cost over decades, it’s actually the smarter investment.

References

American Galvanizers Association. (2021). Hot-dip galvanizing for corrosion protection: A specifier’s guide. https://galvanizeit.org/education-and-resources/publications/hot-dip-galvanizing-for-corrosion-protection-a-specifiers-guide-2012

International Zinc Association. (2020). Life-cycle assessment of hot-dip galvanized steel. https://galvanizeit.org/hot-dip-galvanized-steel-for-transportation/environmental-advantages/life-cycle-assessment-lca