I’m still figuring out the best way to deal with that foam creep too. Every time I use it, even the “no drip” stuff, I end up chasing blobs with a putty knife and cursing under my breath. I read somewhere that if you mist the area with a spray bottle before applying, it helps the foam cure faster and supposedly keeps it from expanding as unpredictably, but honestly, can’t say I noticed a huge difference.
Mineral wool’s interesting—when I tried it, it definitely felt easier to control, but then I kept second-guessing whether I packed it tight enough. Does anyone know if there’s a trick to making sure it really seals? Like, is it better to overstuff a bit or just gently fill?
Painter’s tape is one of those things where I always remember right after I’ve started and see the foam oozing onto the trim… Maybe I need to just leave a roll in every room as a reminder.
Is there any real downside to just living with a tiny draft? Or am I going to regret that when winter hits?
I used to shrug off those tiny drafts too, but last winter I finally sealed up a couple leaky spots and wow—my living room actually felt warmer, and the heat didn’t kick on as much. Even a small draft can add up over time, especially if you’re in a windy spot. With mineral wool, I’ve heard you want it snug but not crammed in—if it’s packed too tight, it can lose its insulating value. Anyone ever try using a piece of cardboard or a ruler to help tuck it in evenly?
Yeah, I’ve done the cardboard trick before—honestly, it works better than just jamming the stuff in with your hands. I usually cut a piece a little wider than the gap, then use it to gently push the mineral wool in so it fills the space but doesn’t get mashed flat. If you cram it too much, it really does lose its loft and stops working as well.
Sometimes I’ll use a paint stir stick instead, especially for those narrow gaps around window frames. Just have to watch you’re not tearing up the vapor barrier or drywall edges. Learned that the hard way once... ended up doing more patching than insulating that day.
Drafts are sneaky, too—one tiny gap can make a room feel way colder than you’d expect. Definitely worth taking the time to do it right, even if it feels a bit fiddly.
- I get the cardboard or paint stick method, but I’ve actually had better luck with a flexible putty knife for those tight spots. Less likely to snag the vapor barrier since it’s smooth, and you can really control the pressure.
- Honestly, sometimes I skip mineral wool altogether around windows and use low-expansion foam. It fills every gap, no cold spots, and you don’t have to worry about compressing anything. Downside is cleanup if you overdo it... learned that one the messy way.
- I do agree on not jamming insulation in too tight—seen way too many folks squash it flat and then wonder why their rooms are drafty.
- For what it’s worth, I think it’s worth spending a bit more time with a good blade or tool rather than improvising with whatever’s lying around. Makes a difference long-term, especially in older houses where nothing’s square.
Flexible putty knife’s my go-to too—especially when you’re dealing with that stubborn old framing that’s never quite straight. I’ve tried the foam method, but honestly, I always end up scraping dried blobs off the trim for twice as long as it took to apply. If I’m in a rush, sure, but mineral wool gives me fewer regrets later. Biggest thing for me is taking the time to cut insulation so it actually fits instead of cramming it in and hoping for the best... learned that lesson the hard way during one cold winter.
I hear you on the foam—tried it once and spent more time cleaning up than actually insulating. I keep coming back to mineral wool too, but I always wonder about the long-term air sealing. Do you use anything to back up the mineral wool, like caulk or tape, or just rely on a snug fit? I’ve had a couple of drafty corners show up a year or two later and can’t decide if I should be sealing those edges somehow or if that’s just par for the course with old houses.
I get what you mean about mineral wool—I've used it in a few retrofits, and honestly, a snug fit alone never seems to cut it long-term, especially in older homes with shifty framing. I usually run a bead of high-quality caulk or acoustic sealant around the perimeter before packing in the batts. Tape can help too, but it doesn't always stick well to rough surfaces or hold up over time. Have you tried using a backer rod plus sealant in those trickier gaps? Sometimes it's the only thing that keeps those drafts from sneaking back in... Old houses just love to find new ways to leak air, don't they?
Backer rod plus sealant definitely helps in those weird, uneven gaps—especially where the framing's moved over the years. Mineral wool alone just doesn't cut it for air sealing, in my experience. I’ve had tape peel off old plaster more times than I’d like to admit... Caulk holds up better, but even then, I’m always half-expecting to find a new draft next winter. Old houses never make it easy.
Yeah, I’ve run into the same thing—mineral wool’s great for sound, but not for stopping drafts. I usually wedge in backer rod and then a flexible sealant, especially on those weird, out-of-square window frames. Sometimes I’ll use a painter’s caulk for the final touch, but it’s never perfect. Old plaster just doesn’t want to hold onto anything sticky for long... It’s like these houses are determined to keep you guessing every winter.