Silicone gaskets definitely outperform standard rubber in terms of UV and temperature resistance, but I’m curious—did you notice any issues with adhesion or shifting after those hailstorms? Sometimes the sealant can separate under repeated impact, especially on older metal panels.
Funny you mention shifting after hail—last spring, I inspected a place where the homeowner swore his “indestructible” silicone gaskets would outlive the house. Well, after a golf-ball-sized hailstorm, those gaskets were still hanging on, but the sealant had started to peel away in spots, especially around the seams where the metal panels flexed. It wasn’t catastrophic, but you could see daylight in a few places if you looked close enough.
I’ve noticed older metal roofs (think 30+ years) are more prone to that kind of separation. The panels just don’t have the same rigidity anymore, so every impact seems to loosen things up a bit more. Silicone does hold up better than rubber, no question there, but it’s not immune to repeated pounding. Sometimes the fix is as simple as reapplying a bead of sealant, but if the panels are warped, it turns into a game of whack-a-mole.
Honestly, I’d take silicone over rubber any day for UV and heat, but after a big storm? Always worth a close look—sometimes even the “indestructible” stuff needs a little TLC.
Sometimes the fix is as simple as reapplying a bead of sealant, but if the panels are warped, it turns into a game of whack-a-mole.
That “whack-a-mole” description is spot on. I’ve been living with an old-school metal roof since the late 90s, and after every big hailstorm, I find myself crawling around up there with a flashlight and a tube of sealant, chasing leaks that seem to move around every year. My neighbor swears by that clear silicone stuff, but honestly, I’ve had mixed luck. It holds up great in the sun, but the freeze-thaw cycles seem to make it brittle in some spots.
One thing I’ve noticed—maybe it’s just my roof’s age, but the seams where two panels meet always seem to be the weak link. Even if the panels themselves look fine, those little gaps show up after a good pounding. I’ve tried the fancy “eternabond” tape too, but it’s not a miracle fix.
At this point, I’m just happy if I can keep the attic dry until I can budget for a full replacement. Metal roofs are tough, but yeah, even the “indestructible” stuff needs babysitting once it gets up there in years.
I hear you on the seams—those are always the first spots I end up checking after a storm. Had a place a few years back where the panels themselves were fine but the overlap joints just kept letting water sneak in. Ever tried using those butyl rubber tapes instead of silicone? I’ve wondered if they’d hold up better through winter, but haven’t taken the plunge yet...
- Butyl tape’s definitely got its fans, but I’ve seen it lose adhesion in spots where there’s a lot of freeze/thaw cycling.
- Silicone can be messy, but it tends to flex better with the metal as temps swing—especially on older roofs that shift a bit.
- Had a client last winter who used butyl on a north-facing seam... by March, water had crept under and started rusting the fasteners.
- If you’re dealing with a lot of movement or temp swings, I’d lean toward a high-quality silicone or even a hybrid sealant.
- Just my two cents—sometimes the “old school” stuff holds up better than the new tapes, at least in our climate.