Interesting you mention climate—I hadn't really thought about that before. I'm pretty new to all this home maintenance stuff, but your comment got me thinking about my own experience last fall. I live in a pretty humid area, and when I first moved in, the previous owner had used polyurethane on some metal flashing around the chimney. At first glance, it looked fine, but after a closer inspection (and a particularly rainy season), I noticed it had started cracking and peeling away.
I ended up redoing it with silicone based on a friend's recommendation, and so far it's holding up way better. But now I'm wondering if humidity plays as big a role as cold temperatures do? Maybe polyurethane just doesn't handle extremes well—whether it's cold or moisture?
Also, funny enough, my neighbor swears by polyurethane and says silicone never sticks properly for him. He's lived here forever and seems to know what he's talking about, so maybe there's more to it than just climate...could be prep work or even the specific brand used?
Anyway, it's interesting how different experiences can be even within the same region. Makes me wonder if there's some hidden trick or detail we're all missing...
Had a similar experience myself. When I first moved in, I used polyurethane around some flashing because that's what the guy at the hardware store recommended. It looked great at first, but after one winter it was cracking and peeling like crazy. Switched to silicone after properly cleaning and roughing up the surface, and it's been solid ever since. Honestly, prep work seems to matter just as much as the product itself...
Silicone's definitely a step up from polyurethane, but personally I've found that roofing-specific sealants like butyl rubber hold up even better long-term. Silicone can sometimes struggle with adhesion on metal surfaces, especially if there's any flex or movement...just something to consider.
Have you had adhesion issues with silicone on metal specifically, or is it more about movement and flex in general? I've used silicone plenty of times on metal edging and flashing, and honestly haven't run into much trouble as long as the surface prep is solid. Usually, if there's a problem, it's because someone skipped cleaning the surface thoroughly or didn't rough it up enough beforehand.
Butyl rubber is definitely durable stuff, no argument there, but I've found it can sometimes be a bit messier to apply and harder to work neatly into tighter spots. Have you noticed that too, or maybe it's just me being impatient? I guess it depends on the exact application—if you're dealing with a lot of movement or expansion/contraction, something more flexible and forgiving like butyl might indeed be better.
Another thing I wonder about is UV exposure. Silicone tends to handle sunlight pretty well over the years without cracking or breaking down much. Have you noticed how butyl rubber holds up under heavy UV conditions long-term? I've seen mixed results myself—some roofs look great after 10+ years, others start looking rough after just a few summers.
Anyway, not knocking your experience at all—just curious if maybe the silicone adhesion issue might be more of a prep problem rather than the product itself. Sometimes it's easy to blame the sealant when it's really about how it's applied.
Yeah, silicone adhesion usually comes down to prep in my experience too. I've inspected plenty of roofs where silicone was peeling off metal, and almost every time it was because someone skipped cleaning or didn't scuff the surface properly. Butyl can be great, but you're right—it's messy stuff, especially in tight corners. As for UV, I've seen butyl hold up surprisingly well, but it seems to depend a lot on brand quality and climate. Definitely a mixed bag there...
