Had the same issue about five years back—metal roof, coastal air, and it was the screws that rusted out first, not the panels. I swapped out just the fasteners with stainless ones. It slowed things down, but honestly, if there’s already rust stains inside, you might be chasing leaks for a while. Worked as a stopgap for me, but eventually had to redo sections where water got in around old holes. If you’re seeing stains, check your insulation too—moisture loves to hide there.
Interesting point about the screws going first—I’ve seen that too, especially on older installs where they used cheaper fasteners. Did you notice if the rust stains inside lined up with the screw locations, or was it more random? Sometimes I wonder if swapping to stainless is enough, or if the old holes just end up being weak spots no matter what you do.
I’m curious—when you redid those sections, did you have to replace any insulation or sheathing? I’ve had a couple buildings where the moisture got into the fiberglass batts and it was a pain to dry out. Also, did you try any of those protective coatings on the panels themselves, or just stick with replacing hardware? I’ve heard mixed things about how well those coatings hold up in salty air, but haven’t tried them myself.
It’s wild how much more maintenance coastal roofs need compared to inland ones. Makes me wonder if aluminum panels would be worth the extra cost in the long run, or if it’s just trading one problem for another.
Funny you mention the rust stains lining up with the screws—I noticed the exact same thing when I pulled a few panels off our shed last fall. The worst spots were always right under the old fasteners, especially where the heads had basically dissolved. I swapped to stainless on the new section, but honestly, I’m still a little paranoid about those old holes. Even after filling them with sealant, it’s hard to believe they’re as strong as untouched metal.
When I tore out a section over the laundry room, I found the fiberglass insulation was basically toast. It was damp and smelled awful. I tried airing it out but ended up replacing it. The sheathing was mostly okay—just a couple soft spots near where water had been dripping for who knows how long. That was a pain because I had to cut out and patch those bits before putting everything back together.
I looked into those coatings you mentioned, but after reading some reviews (and seeing how salty our air gets), I figured it wasn’t worth the extra money for me. Maybe if I was doing a whole new roof or lived even closer to the beach, but for patch jobs, just swapping hardware and keeping up with sealant seems easier.
Aluminum panels sound great in theory—lighter, no rust—but my neighbor went that route and he says they dent super easily. Plus, they were way pricier than steel when he did his roof last year. It’s like you solve one problem and get another... At this point, I’m just hoping regular checks and quick fixes will buy me a few more years before having to do something major.
Coastal roofs are definitely their own kind of headache. Inland folks don’t know how easy they have it sometimes.
That’s been my experience too—old fastener holes always make me nervous, even with sealant. I’ve seen leaks sneak back in after a couple years, especially on the windward side. Stainless helps, but nothing’s totally maintenance-free out here. I’ve patched more soggy insulation than I care to remember... Seems like coastal roofs just need constant babysitting. Aluminum’s tempting, but yeah, dents are a pain and the price is rough. Regular checks and quick fixes are probably the best bet unless you’re ready for a full redo.
old fastener holes always make me nervous, even with sealant. I’ve seen leaks sneak back in after a couple years, especially on the windward side.
That lines up with what I’ve seen during inspections—sealant just doesn’t last as long as people expect, especially when it’s constantly battered by salt and wind. Stainless fasteners do slow down corrosion, but I’ve still found rust stains around them after a few seasons. Has anyone tried using butyl tape under the fastener heads before sealing? Curious if that’s actually held up for folks in the long run, or if it’s just another temporary fix.
