I’m with you on the dehumidifier—ours is basically a family member at this point. I do think some fog is just life, especially in older houses. For me, if it’s just a little mist on cold mornings, I don’t stress. But when I started seeing water pooling on the sill last year, that’s when I realized my seals were shot. Replacing them wasn’t cheap, but it made a difference. Sometimes it’s just winter, sometimes it’s a sign your windows are tired... tricky to tell until you’re mopping up puddles every day.
If you’re seeing just a bit of fog on the glass, especially first thing in the morning, it’s usually just a humidity vs. temperature thing—pretty normal, especially if you’ve got older single-pane windows (like me, still hanging onto mine from the ‘70s). But once you start noticing water actually pooling on the sill or feeling dampness along the frame, that’s where I draw the line. In my experience, that’s almost always a failed seal or a bigger insulation issue.
I replaced all the gaskets and caulking around my living room windows two winters ago. Not cheap, and honestly a pain to do right, but it cut down on both condensation and drafts. Funny enough, my neighbor swears by those shrink-wrap window kits every winter... I tried them once, but they just felt flimsy.
Dehumidifiers definitely help, but if you’re mopping up puddles, that’s more than just weather. At that point, you’re risking rot or even mold. I’d say don’t wait too long to address it—window repairs are annoying, but replacing a whole sill or dealing with black mold is way worse.
That’s spot on—just a little fog is pretty normal, especially if you’re running heat and it’s cold outside. But when you start seeing water actually collecting or the frame feels damp, you’ve got to deal with it. I did the caulking and weatherstripping thing a couple years back too, and yeah, it wasn’t cheap or quick, but my energy bills dropped after. I’ve tried those plastic window kits as a stopgap… honestly, they helped a bit but felt kind of temporary. If you’re getting puddles, though, that’s the point where I’d look at replacing seals or even upgrading the window if you can swing it. Mold is no joke.
Plastic window kits are a decent quick fix, but like you said, they’re not really a long-term solution. When I see condensation between the panes (not just on the inside surface), that’s usually a sign the seal’s failed. Have you noticed if the fog is only on cold days, or is it sticking around even when things warm up? Sometimes that helps narrow down if it’s just weather or something more permanent going on with the window itself.
- Totally get where you're coming from—those plastic kits are handy in a pinch, but I’ve never found them to last more than a season or two.
- You’re spot on about the condensation between the panes. That’s how I realized a couple of mine needed attention last winter. If it’s just on super cold days and disappears when things warm up, sometimes it really is just the weather messing with you.
- But if the fog hangs around no matter what, or seems to get worse over time, that’s usually when I start thinking about a seal issue. Had one window like that, and it just never cleared up... turned out the seal had totally failed.
- It’s easy to worry, but honestly, even if it is a seal problem, you can take your time planning a fix. Mine was foggy for months before I got around to replacing it.
- Either way, you’re not alone—seems like everyone with older windows runs into this at some point. It’s fixable, even if it’s annoying.
- If you’re seeing fog inside the glass that won’t clear up, it’s usually a busted seal—weather’s not gonna fix that one.
- Quick tip: if you’re only getting condensation on the interior surface, it’s more about indoor humidity.
- Honestly, I’ve seen folks live with cloudy panes for years before swapping ‘em out. Not urgent unless you can’t stand the look.
- Those plastic kits are a temporary fix at best... I call them “winter band-aids.”
- Gotta admit, I’m not totally on board with the “not urgent unless you can’t stand the look” idea. I get it—cloudy panes aren’t the end of the world, but in my experience, a busted seal can eventually make things worse.
- Had a living room window that started out just a bit foggy. Ignored it for a couple years, and next thing I knew, there was a bit of mold creeping along the frame. That’s when it stopped being just a cosmetic thing for me.
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Those plastic kits are a temporary fix at best... I call them “winter band-aids.”
Totally agree here. Used those kits on an old rental—helped with drafts, but didn’t touch the real problem. The plastic always peeled off by spring anyway.
- One thing I’d add: if you’re noticing condensation between the panes, especially in older double-glazed windows, you might see your energy bills creep up. The insulation isn’t working like it used to. Not a crisis, but something to keep an eye on if you’re trying to keep the house efficient.
- As for “weather’s not gonna fix that one”—yeah, if there’s moisture between the glass, it’s not just a winter issue. But sometimes, what looks like fog is just surface condensation from cooking or showers. I usually run a fan or crack a window before calling it a window problem.
- In my book, if you see any staining or feel cold drafts, it’s probably time to deal with it. Otherwise, I’d say live with it until you’re ready for a bigger project—just don’t wait forever if you spot mold or rot starting up.
Anyone else notice their old windows getting worse after a particularly rough winter? I swear mine always act up after big temperature swings...
I’ve noticed the same thing with my old windows after a wild winter. Last year, we had a couple of those freeze-thaw cycles and, sure enough, the kitchen window that was just “a little foggy” turned into a full-on science experiment by March—condensation between the panes, and the wood trim started feeling soft in one corner. That’s when I realized it’s not just about looks.
“if you see any staining or feel cold drafts, it’s probably time to deal with it.”
Couldn’t agree more. I tried the plastic film trick too—just ended up peeling off in April, and honestly, didn’t do much for comfort. What gets me is how fast things can go from “eh, it’s fine” to “why does this smell musty?” Maybe some folks get away with ignoring it for years, but around here (northeast), those temp swings seem to push any weak seals over the edge.
If you start seeing mold or the frame gets spongy, that’s my cue to stop waiting. Otherwise, I’ll admit—I’ll live with a little fog if I’m not ready to pony up for new windows yet.
If you start seeing mold or the frame gets spongy, that’s my cue to stop waiting.
Right there with you. I’ve pulled out enough soggy sills to know once the wood starts feeling soft, you’re past the “wait and see” phase. I’ve seen folks try to caulk over the problem or slap on more plastic, but honestly, it just traps more moisture. The fog between panes is annoying, but when you catch that musty smell or see paint blistering, it’s time to bite the bullet. Northeast winters are brutal on old windows—the freeze-thaw really does a number. I’d rather swap a window than deal with rot crawling down into the framing... learned that one the hard way.
I get where you're coming from about not waiting once the frame gets soft or moldy, but I think sometimes folks write off foggy panes a bit too quickly. I’ve lived with a couple of fogged-up windows for years in my 1950s place, and they’re still structurally sound—no rot, no musty smell, just not as pretty. For me, it’s mostly a cosmetic issue unless you start seeing actual water pooling or the wood starts to go.
I agree that trapping moisture with plastic is a mistake, but I’ve had luck with those dehumidifier packs inside the frame—maybe just buying time, but it hasn’t made things worse. Replacing windows isn’t cheap, especially with custom sizes in older homes. Sometimes, I’d rather put up with a little fog than take on a full replacement unless there’s real damage.
Maybe it depends on how picky you are about looks versus function. I’m more of a “if it ain’t broke, don’t fix it” type, at least until the evidence says otherwise.