Funny how it’s always the smallest holes that cause the biggest headaches...
Right? I once spent an hour sealing a gap the size of a pencil eraser, only to find a cricket had already claimed it as prime real estate. I hear you on mineral wool—love the green factor, but after my last flood, I’m leaning toward rigid foam too. It’s not perfect for every spot, but at least it doesn’t turn into a science experiment if it gets wet. Still, I keep a stash of caulk and random scraps handy for those “surprise” gaps. Never fails—if there’s a hole, something will find it.
- Totally agree about rigid foam—after my basement took on water, I swapped out the old fiberglass for foam board wherever I could.
- For the tiny gaps, I’ve had decent luck with that expanding spray foam (just don’t overdo it or you’ll be trimming blobs for days).
- Caulk is a lifesaver, but I’ve found painter’s tape helps keep things tidy when sealing along baseboards.
- Not sure mineral wool is worth the hassle in flood zones... dries slow and gets funky fast.
- I keep a bucket of leftover foam scraps too—never know when you’ll need to plug a weird corner.
Caulk is a lifesaver, but I’ve found painter’s tape helps keep things tidy when sealing along baseboards.
Totally agree about the painter’s tape trick—makes cleanup way easier, especially if you’re working with white trim and don’t want to risk smudges. I’ve also started using a flexible caulk tool instead of my finger for those longer runs; it gives a much smoother finish and saves on wipes.
On the mineral wool front, I hear you. I tried it once in a crawlspace that flooded every spring, and it just turned into a soggy mess. Ended up ripping it out and going with foam board like you mentioned. The only spot I still use mineral wool is between joists above grade, where moisture isn’t as big a worry.
Curious if anyone’s had luck with those waterproofing paints or sealers on basement walls before insulating? I’ve seen mixed reviews, but never tried them myself. Wondering if they actually help or just delay the inevitable.
Waterproofing paints are a bit of a gamble, in my experience. I tried one of those “miracle” basement sealers a few years back—followed the directions, slapped on two coats, and crossed my fingers. Looked great for about a year, then the telltale damp spots started creeping back in. Turns out, if water wants in, it’ll find a way (especially if you live somewhere with a stubborn water table).
Honestly, I think they’re more of a temporary band-aid than a real fix. If you’ve got serious moisture, it’s probably better to tackle drainage outside—gutters, grading, maybe even a French drain—before trusting paint to keep things dry. That said, if you just get the occasional musty smell and not actual puddles, the paint might buy you some time.
And yeah, mineral wool in a wet crawlspace is just asking for trouble. Learned that lesson the messy way...
“if water wants in, it’ll find a way (especially if you live somewhere with a stubborn water table).”
Couldn’t agree more—water is relentless. I once designed a basement family room where the owners insisted on just using sealant paint, and within two years, the new carpet was toast. Now I always suggest starting with the “boring” stuff—grading, drains, sump pumps—before getting creative with interiors. And mineral wool in a damp crawlspace? Been there, done that, had to rip it all out. These days, I lean toward closed-cell spray foam for tricky spots. It’s not cheap, but it holds up way better in the long run.