How I finally stopped that gross black stuff from creeping up my window sills

Really glad to hear your strategy is working. I’ve had similar luck after switching to a small dehumidifier last winter - didn’t think it’d make much difference, but it actually kept the humidity in check. I still get a little nervous during the first big rain, though.

“...used a cheap dehumidifier, and - knock on wood - haven’t seen any mold since.”

Cracking the windows helps too, even if it feels counterintuitive when it’s cold out. I found that scrubbing the frames with diluted vinegar every couple of months also seems to keep the black stuff from coming back as quickly. It’s not foolproof, but definitely less of a headache than before.

- Had no clue window mold was a thing until I bought this place... now it’s my arch nemesis.
- Tried the vinegar trick - works, but my house smelled like a salad for a day.
- Dehumidifier in the bedroom made a bigger difference than I expected, but it’s kinda noisy. Tradeoff, I guess.
- Still not convinced about cracking windows in January. Maybe I’m just lazy or hate being cold?
- Anyone else notice it comes back faster if you skip cleaning even once?

That black stuff drove me nuts in my last house - old wood windows, single pane, you name it. Vinegar helped, but yeah, it’s not exactly a spa day for your nose. I ended up swapping out the worst windows for double-pane units with better seals, and honestly, mold showed up way less after that. Still, if you’re not ready for new windows, keeping those sills dry is key. I hear you on the dehumidifier noise though... mine sounded like a jet engine at night. Skipping a week of cleaning definitely made it worse for me too. Mold waits for no one.

Double-pane windows sound dreamy, but my wallet would probably faint. I totally relate on the dehumidifier noise - mine’s got this weird rattle that kicks in right as I’m falling asleep. Funny how mold seems to sense when you slack off, too. I swear it’s got a sixth sense for laziness…

Double-pane windows sound dreamy, but my wallet would probably faint.

Honestly, I hear you on the sticker shock. But have you checked out storm windows or even some of the newer window films? Sometimes they do a halfway decent job for a fraction of the cost. Not saying it’s the same as double-pane, but if your main beef is condensation and mold, those can help more than folks think. Also, about that dehumidifier rattle - mine once started humming like it was auditioning for a jazz band. Ever tried putting it on a rubber mat? Sometimes cuts the noise down. Mold really does seem to know when you’re tired... uncanny.

Sometimes they do a halfway decent job for a fraction of the cost.

That’s been my experience too. I slapped some insulating film on my single panes last winter - not pretty, but it actually helped cut down on the sweaty glass. Anyone ever tried those magnetic interior storm windows? Curious if they’re worth the hassle.

- Tried the magnetic storms last year - mixed results.
- They did cut drafts, but honestly, the install was more fiddly than I expected.
- My sills still got damp since condensation just moved to the outer glass.
- For me, a dehumidifier made a bigger difference than any window fix.
- Anyone else notice that? Maybe it’s just our old plaster walls...

Yeah, I noticed the same thing with condensation just shifting around. Tried window film and draft stoppers, but the real game changer was a cheap dehumidifier in the bedroom. Old walls here too - think it’s just how these houses breathe, honestly.

Yeah, I noticed the same thing with condensation just shifting around.

That’s interesting - using a dehumidifier made that much of a difference? I’ve always wondered if it’s just “how these houses breathe,” like you put it, or if there’s something more going on with older plaster and brick. I’ve tried the window film route too, but sometimes it felt like the moisture just found a new spot to hang out. Did you notice any changes in your energy bills after running the dehumidifier, or was it pretty negligible? Kind of curious if it’s worth leaving one on all winter...

sometimes it felt like the moisture just found a new spot to hang out.

Yeah, totally get that - like playing whack-a-mole with damp patches. Here’s what I noticed:

- Dehumidifier helped a lot, but not magic. Less black stuff, but it didn’t fix window condensation 100%.
- Energy bill bump? Maybe $10-15/month running it on low. Not nothing, but cheaper than scrubbing mold every weekend.
- Old brick + plaster seems to make things sweat more. My 1950s place just loves to “breathe”... or leak.
- Window film helped a bit, but honestly, the dehumidifier made the biggest dent.

If you hate wiping windows every morning, I’d say it’s worth a shot.

like playing whack-a-mole with damp patches

Really relate to this. We put in a dehumidifier too - same deal, not a miracle but it made mornings way less gross. The little energy bump is annoying, but honestly, worth not scrubbing mold all the time. You’re not alone with the old house “breathing” thing either... ours seems to find new ways to surprise us every season.

- Totally get the “house breathing” struggle… mine’s like a living organism with a grudge against dry walls.
- Dehumidifier helped, but I swear it’s a dust magnet now. Anyone else notice that?
- I tried one of those humidity sensors that sync to my phone - kinda fun watching the numbers drop, but not exactly thrilling.
- Curious if anyone’s messed with smart fans or window sensors? Or maybe I’m just overcomplicating things for an old house that wants to stay quirky.

I hear you on the dehumidifier dust thing - mine fills up with gunk so fast I’m starting to think it’s just vacuuming the air for me. I’ve got an older place too, and it’s like every season brings a new “quirk.” I tried a smart fan setup last winter, just one of those plug-in ones that links to my phone. Honestly, it was kind of cool to see the humidity dip when the fan kicked on, but it didn’t magically solve the window mold. Still had to scrub those sills every couple weeks.

What actually made a difference for me was caulking the heck out of any tiny gaps around the windows and running the bathroom fan longer after showers. That, plus keeping the blinds open for sunlight, seems to have slowed down the black stuff. It’s not perfect - sometimes I think old houses just want to do their own thing - but at least I’m not scrubbing mold every weekend now.

I’ve seen folks rave about window sensors, but I haven’t gone down that rabbit hole yet. Maybe I’m just not ready to turn my house into a science experiment…

Man, I totally get that - old houses just have a vibe, right? I’ve chased window mold for years and honestly, short of ripping everything out, it’s always a battle. I tried those window sensors once - kinda cool to see the data, but after a while it felt like I was just collecting proof my place is damp. Curious, did you ever try using those moisture absorbers (like DampRid) along the sills? I found they helped a bit in the worst corners, but maybe that’s just me being hopeful...

I’ve definitely been there - my 1920s place is like a petri dish in the winter. I tried those moisture absorbers too, and honestly, they did soak up a surprising amount in the corners. The downside is I kept forgetting to empty them, so then I just had these weird little buckets of swamp water everywhere. I actually had better luck with a small dehumidifier near the worst window, but it’s not exactly energy efficient. Mold’s relentless, man...

Yeah, those moisture absorber tubs are basically just mold’s waiting room if you forget about them. I’ve tried both - the absorbers and a dehumidifier - and honestly, the dehumidifier wins for actually making a dent, but I hate how much it runs up my electric bill. What helped me a bit was sealing up the window drafts with that shrink film stuff. It cuts down on condensation, so there’s less moisture to feed the mold in the first place. Not perfect, but at least I don’t feel like I’m living in a swamp anymore.

I’ve always been a bit suspicious of those moisture absorber tubs - had a couple in my basement years ago and, yeah, they did soak up some water, but then I’d forget about them and end up with this weird, sludgy mess. Not sure if they ever really helped or just gave me another thing to clean.

Dehumidifiers do work, but I’m with you on the electric bill. Mine kicked on constantly last summer and I started wondering if it was actually saving me money by preventing damage or just eating into my wallet in a different way. Did you notice any difference in your air quality after sealing the windows? I tried the shrink film once and it definitely cut down on drafts, but I still got some condensation - maybe I didn’t seal it right?

Curious if anyone’s tried those trickle vents or something less energy-hungry. Seems like every fix has its own set of headaches...

Shrink film helped with drafts for me too, but yeah, condensation still popped up on the coldest days. I think it’s just the nature of older windows - no perfect fix. I actually tried those trickle vents last winter after getting tired of running the dehumidifier 24/7. They let in a bit of fresh air without a big draft, and I swear the sills stayed drier. Not a miracle cure, but less hassle than emptying tubs or babysitting the dehu all day.

I tried trickle vents too after getting fed up with the endless cycle of wiping down sills every morning. They helped a bit, but I still get some moisture on really cold nights - guess that’s just what you get with 1950s windows. Funny thing, I once tried leaving the bathroom door open at night to “share” the dry air from the rest of the house... didn’t help much, just made everything colder. At least with the vents, I’m not dumping buckets out of the dehu all winter. Not perfect, but less annoying for sure.