- Been there with the mismatched fasteners. Did a patch job on my shed roof last fall—ran out of stainless, so I used whatever was left in the garage. Looks like a checkerboard now, but it’s dry inside.
- Salt air just eats up anything that’s not stainless or copper. Galvanized barely lasted two years for me before the rust stains started running down the siding.
- Stainless is pricey, but I figure it’s cheaper than redoing the whole thing every couple seasons. Still, I only swap them out when they fail—can’t afford to do the whole roof at once.
- Tried painting over some of the old fasteners with Rustoleum... didn’t last long, but bought me a few extra months.
- Honestly, I’d rather have ugly screws than another leak in the bedroom. Not winning any curb appeal contests, but it works for now.
- Anyone else notice even “marine grade” stuff doesn’t always hold up? Maybe it’s just our spot—wind blows straight off the bay.
I see this all the time during inspections along the coast. Folks think “marine grade” is a magic bullet, but honestly, not all stainless is created equal—304 will pit and rust way faster than 316 if you’re right on the water. And even then, if you get a bad batch or the coating’s thin, salt air finds its way in. I’ve seen roofs less than five years old with fasteners that look like they’ve been there for decades.
Mixing metals can make it worse, too—galvanic corrosion kicks in if you’ve got copper touching steel or even some types of aluminum. It’s ugly and eats through stuff faster than most people expect. I get why folks use whatever’s handy, though. Stainless is expensive, and swapping every screw at once just isn’t realistic for most budgets.
Painting does help a bit, but like you said, it’s just buying time. I’ve had clients try those rubberized sprays—sometimes they last a season or two longer than paint, but nothing really beats using the right fastener up front. In these salty spots, ugly but functional usually wins out over pretty every time... unless you want to be up there replacing things every year.
That’s interesting about the difference between 304 and 316. I did a bunch of research before we replaced our deck fasteners, and it’s wild how much faster 304 corrodes right by the ocean. I ended up paying extra for 316, but even then, I noticed some surface rust after a couple years—maybe just cosmetic, but still annoying. The galvanic corrosion thing caught me off guard too... I had no idea mixing stainless and aluminum could cause so many problems until I saw it firsthand under our gutter brackets.
Man, I hear you on that sneaky surface rust. I swapped out all my porch rail bolts for 316 a few years ago thinking I was set for life, but the salty air still found a way to make them look tired. The kicker? My neighbor mixed stainless with some old aluminum brackets and ended up with what looked like a science experiment gone wrong—white crust, pitting, the works. Sometimes it feels like the ocean’s just waiting for us to try something new, so it can eat it alive...
My neighbor mixed stainless with some old aluminum brackets and ended up with what looked like a science experiment gone wrong—white crust, pitting, the works.
That galvanic corrosion sneaks up on folks all the time. I actually think a lot of people overrate 316 stainless as a cure-all near the coast. It’s definitely better than 304, but in my experience, even the best grades need regular rinsing if you’re right by the water. The salt just sits there and starts doing its thing.
I’ve seen some folks have better luck with hot-dip galvanized fasteners for certain applications, especially if they’re paired with similar metals. Not saying they’re perfect—eventually that zinc coating wears down—but at least you don’t get that weird electrochemical mess when you mix metals.
Honestly, nothing’s totally maintenance-free out here. My uncle tried powder-coating his railings and it bought him a few extra years before the rust crept in again. At this point, I just figure on giving everything a rinse every couple weeks and keeping an eye out for trouble spots... beats having to replace hardware every few years.
