Interesting approach with the cold galvanizing spray—haven't tried that myself, but it makes sense. I've managed a few properties right on the coast, and honestly, galvanized metal has always been a mixed bag for me. Even with prep, I've seen it rust out pretty quickly in some cases, especially if there's any spot you missed or if the coating gets scratched during installation.
That said, your method sounds pretty thorough. The marine enamel topcoat probably helps a lot. I've mostly stuck to aluminum flashing or stainless steel hardware whenever budgets allowed, just because the maintenance is lower and the lifespan is longer. But yeah, stainless steel prices lately... ouch.
One thing I'd add from experience: if you're going galvanized, pay extra attention to fasteners. I've seen plenty of galvanized flashing hold up okay, only to have the screws or nails rust out first and cause leaks. Stainless fasteners are worth the extra cost even if you're using galvanized flashing.
And totally agree about seam tapes—tried them once on a coastal property and regretted it within a year. Salt air just eats through adhesives like nothing else.
Overall, I'd say galvanized can work if you're meticulous about prep and maintenance, but it's definitely not a set-it-and-forget-it solution near saltwater. If you're willing to put in the time and effort for regular inspections and touch-ups, it can be cost-effective. But if you're managing multiple properties or don't have time for frequent upkeep, aluminum or stainless might save you headaches down the road.
I've been considering galvanized metal for a coastal roof too, mostly because stainless steel is way out of my budget right now. Good tip on the fasteners—I hadn't thought about them rusting out first. Has anyone tried aluminum flashing long-term? Curious if it holds up better against salt air or if there are other issues I'm not thinking about...
I installed aluminum flashing on a coastal property about seven years ago, and it's held up surprisingly well. Definitely better than galvanized steel, which started showing corrosion within just a couple of years. Aluminum does oxidize, but the oxide layer actually protects it from further damage. One thing though—make sure it's properly isolated from other metals, or you might run into galvanic corrosion issues. Learned that the hard way when some steel nails caused localized corrosion spots...
Good points about aluminum. Been using aluminum gutters and flashing on my coastal place for about ten years now, and they're holding up nicely—way better than the galvanized stuff I've used before. You're spot-on about isolating metals. I had a similar issue when I mixed screws without thinking... learned quickly that stainless steel fasteners are worth the extra cost. Glad yours is working out overall, sounds like you're on the right track.
I've had pretty good luck with aluminum too, but I'm curious—did you ever try copper flashing or gutters? I've heard copper can hold up really well in salty air, but the price always scared me off. Also, totally feel your pain on the mixed screws thing... learned the hard way myself. Speaking of fasteners, did you notice any corrosion on your aluminum where it contacts stainless screws directly, or did you use some kind of barrier between them? I ended up using nylon washers after noticing some weird white powdery stuff forming. Not sure if that was overkill or not, but it made me feel better, haha. Anyway, glad your setup's holding strong. Sounds like we're all getting smarter (slowly!) about this salty-air roofing business.
