Cutting out drywall is definitely the right move if you spot visible mold, but I’d also check for hidden leaks—sometimes it’s a slow drip from a pipe or even condensation on cold water lines that’s causing the issue. I’ve seen folks chase musty smells for weeks before realizing it was a tiny pinhole leak behind a wall. Dehumidifiers help, but if you don’t fix the source, the smell just keeps coming back. Don’t forget to check floor drains too... they can dry out and let sewer gas in, which smells just as bad as mold sometimes.
I get where you’re coming from, but I wouldn’t jump straight to cutting out drywall unless there’s obvious damage or mold. Sometimes a musty smell pops up just from humidity spikes or stuff stored too close to the walls. Like you said,
—but sometimes the “source” is just poor airflow or a forgotten pile of damp laundry. I’d start with the easy stuff before tearing into walls.“Dehumidifiers help, but if you don’t fix the source, the smell just keeps coming back.”
I’ve definitely been down the “what’s that smell?” rabbit hole in my own basement. One time, I was convinced there was a leak behind the wall, but it turned out to be a soggy cardboard box tucked behind some old paint cans. Felt a bit silly after tearing half the storage area apart. I agree—no need to go full demo mode unless you see real signs of trouble like stains or visible mold.
I’d add that sometimes even just rearranging stuff and running a fan for a few days can make a big difference. Basements are weird like that—one week they’re fine, next week it smells like a wet dog moved in. If you’ve got carpet down there, that can hold onto musty smells too, especially after a humid spell.
Long story short, I’d poke around for obvious culprits before grabbing the utility knife. Sometimes it really is just a forgotten towel or an old gym bag...
I get where you’re coming from—sometimes it really is just a rogue box or towel causing the stink. But honestly, I’d be a bit more cautious if that musty smell shows up overnight. Here’s why:
- Sudden changes can mean water intrusion, even if you don’t see stains yet. Sometimes leaks are hidden and only show up after a while.
- Mold can start growing in as little as 24-48 hours if there’s moisture, and not all mold is visible right away.
- If you’ve got carpet or drywall down there, those can hide problems for weeks before anything shows on the surface.
I’m all for running a fan and moving stuff around, but I’d also check for any damp spots along baseboards or behind furniture. Maybe even use a moisture meter if you’ve got one lying around. Better safe than sorry—musty smells have a way of sneaking up on you, and sometimes by the time you see visible signs, it’s already a bigger headache.
Title: What would you do if your basement started smelling musty overnight?
Better safe than sorry—musty smells have a way of sneaking up on you, and sometimes by the time you see visible signs, it’s already a bigger headache.
You’re not wrong there. I once ignored a weird smell in my basement, chalked it up to my son’s hockey gear, and two weeks later I was ripping out soggy drywall. Now, I’m the person crawling around with a flashlight and a suspicious look every time I catch a whiff of must. Fans are great, but if you’ve got carpet, check under it—trust me, you don’t want to find out the hard way.
