Sometimes I swear the roof waits for payday to spring a new leak...
That’s exactly how mine acts too—like it knows when I’m broke. I’ve noticed aluminum tape just doesn’t bounce back after hail, especially on flatter spots. Rubber patches seem to flex better, but yeah, nothing’s bulletproof. Stainless is nice, but my wallet says nope every time.
Rubber patches seem to flex better, but yeah, nothing’s bulletproof.
I’ve actually had kind of the opposite luck—rubber patches worked for a while, but after our last freeze/thaw cycle, they started peeling up at the edges. My neighbor swears by this weird roof cement stuff he slathers on with a putty knife. It looks messy, but apparently it holds up better in hail than anything else he’s tried. I’m not sure about the long-term, though... anyone else notice rubber doesn’t always play nice with older metal?
Rubber patches are a mixed bag for me too. I’ve put them on a couple old barns around here (central Iowa, so lots of freeze/thaw), and they seemed fine at first, but after a couple seasons the edges started curling up just like you said. Especially where the metal was already kind of rusty or had old paint flaking off—seems like rubber needs a super clean surface to really bond. I wonder if that’s part of the issue with older metal roofs?
That roof cement your neighbor uses—if it’s the black, tar-like stuff—I’ve seen that hold up surprisingly well against hail and even some pretty gnarly wind. It’s ugly, though, and gets all over your hands, but it does seem to last longer than the rubber patches in rough weather. The downside is that once it hardens, it can crack if the metal flexes too much. Not sure how it’d do long-term if your roof moves a lot with temp swings.
Honestly, I haven’t found anything that’s perfect for patching old metal. Rubber is easier to work with but doesn’t always stick for years, especially if there’s rust or grime left behind. Cement lasts longer but can look pretty rough, and sometimes makes future repairs trickier if you need to redo that spot later.
Anyone else notice weird reactions between rubber and certain metals? I had one spot where the patch almost seemed to shrink away from the seam after a couple months, which made me wonder if there was some chemical thing going on or just bad prep.
Don’t get discouraged—seems like everyone’s got their own “magic” fix, but nothing is 100% in this climate. At least you’re catching these issues before they turn into leaks... Sometimes it just comes down to trial and error with whatever materials you’ve got handy.
I get what you’re saying about rubber patches, but honestly, I’ve had better luck with them than with that tar cement stuff—at least on roofs that don’t flex much. The cement always ends up cracking for me after a couple winters, especially on the south-facing slopes. Maybe it’s just the way these old buildings shift around here, but I’d rather reapply a rubber patch every few years than deal with chipping off hardened tar. Prep is a pain either way, though... nothing sticks to rust.
I hear you on the rubber patches, but I’ve gotta say, I’ve seen those things peel up after a couple of hot summers, especially on low-slope metal roofs. Tar cement’s a pain for sure—messy, stinks, and yeah, it’ll crack if you slap it on rust. But if you wire-brush down to clean metal and use a primer first, it actually holds up pretty well. Not perfect, but I’d rather deal with that than chasing leaks every spring. Maybe it’s just the Midwest freeze-thaw cycles messing with everything...