"Try silicone caulk—just scrape out old sealant first, wipe the area clean, then run a smooth bead along the gap."
Silicone caulk is definitely solid advice for sealing drafts, but I'm wondering if it's the best long-term solution for big windows. I've had some trouble with silicone shrinking and peeling after a couple of years, especially in areas exposed to direct sunlight or temperature swings. Have you considered using polyurethane sealant instead? It's a bit tougher to apply neatly (sticky stuff!), but I've found it holds up better over time. Curious if anyone else has noticed silicone wearing out faster than expected...
I've noticed the same thing with silicone, especially on larger windows that get a ton of sun exposure. Did a job a couple years back where the homeowner insisted on silicone because it looked cleaner initially. Sure enough, got a call recently—sealant was peeling and cracking pretty badly. Polyurethane is definitely stickier and messier to work with, but in my experience, it holds up way better over the long haul, especially with temp swings and UV exposure. Worth the extra hassle imo.
"Polyurethane is definitely stickier and messier to work with, but in my experience, it holds up way better over the long haul"
Totally get what you're saying about polyurethane, but I've had pretty decent luck with high-quality neutral-cure silicones designed specifically for exterior use. Did a south-facing bay window about 4 years ago—still looks solid, no cracks or peeling yet. Maybe it's more about choosing the right silicone product rather than silicone itself being the issue...? Just my two cents from personal experience.
Interesting points on both sides here. I've used polyurethane a few times myself, and yeah, it's messy as heck—spent more time cleaning my hands than actually sealing the window, lol. But I gotta admit, once it sets, it's pretty bulletproof. Silicone can be solid too, but I've noticed it depends a lot on prep work and surface conditions. If you nail the prep and pick a good brand, silicone holds up surprisingly well. Otherwise...well, let's just say I've had some less-than-stellar results.
Good points here, especially about prep work—honestly, that's half the battle with any sealant. I've been installing windows for years, and I've seen silicone hold up remarkably well when the surface is clean and dry. But you're right, polyurethane is definitely a beast once it cures. Had a client once who insisted on polyurethane for a large bay window—messy day, gloves ripped halfway through, and I swear I was peeling that stuff off my fingers for days afterward. But the end result was rock solid, zero leaks even after some heavy storms.
Silicone can be a bit finicky, but don't get discouraged by a bad experience or two. If you ever decide to give silicone another shot, try using a good primer first—makes a huge difference in adhesion and longevity. Either way, sounds like you've got a pretty good handle on things already... DIY window jobs aren't easy, so kudos for tackling it yourself.
"Had a client once who insisted on polyurethane for a large bay window—messy day, gloves ripped halfway through, and I swear I was peeling that stuff off my fingers for days afterward."
Haha, been there myself... polyurethane is definitely unforgiving. But honestly, silicone's flexibility can be a lifesaver in certain situations—especially if there's any movement or shifting expected. Polyurethane might be rock solid, but I've seen it crack under stress when the framing isn't perfectly stable. Silicone tends to handle those subtle shifts better. Just something to keep in mind before you commit fully to the poly route next time.
I feel your pain on the polyurethane mess. Last summer, I tackled resealing our big picture window and thought I'd be smart going with poly for durability. Gloves tore almost immediately, and I spent the next three evenings picking dried bits off my hands...ugh. Silicone would've probably been smarter—like you said:
"Silicone tends to handle those subtle shifts better."
Wish I'd known that sooner. Lesson learned for next time, I guess.
I get why silicone seems like the safer bet, but honestly, I've had mixed results with it. Last spring, I resealed our sliding patio door with silicone, thinking it'd handle movement better, but after a year of temperature swings, it started peeling away in spots. Maybe prep was the issue, or maybe it's just not as foolproof as people say? Polyurethane's messy, sure...
"Gloves tore almost immediately, and I spent the next three evenings picking dried bits off my hands..."
...but once it's on properly, it seems to hold up longer. Guess there's no perfect solution here.
I've actually had decent luck with silicone, but prep is definitely key. Last time I used rubbing alcohol to clean the surface first, and it's held up pretty well through two winters now. Maybe worth another shot?
- Tried silicone myself a couple years back, wasn't too impressed.
- Did the whole alcohol prep thing too, but maybe I rushed it... didn't hold up past the first winter.
- Ended up switching to a polyurethane sealant—messier to apply but it's been rock solid since.
- Might give silicone another go someday, but for now I'm skeptical. Glad it's working out for you though.