If it smells musty overnight, moisture's probably already built up somewhere.
Do you ever check behind finished walls or under flooring when that happens? I always wonder if people just run the dehumidifier and hope for the best, or if you actually go hunting for the source. Where do you usually start looking?
Where do you usually start looking?
I get what you mean about just running the dehumidifier and crossing your fingers, but honestly, that feels like putting a band-aid on a leaky pipe. I’ve pulled up carpet before and found a science experiment growing underneath—lesson learned. Usually, I start with the obvious suspects: sump pump, window wells, and any spots where the wall meets the floor. Ever had to cut into drywall to chase down a smell? That’s always a fun surprise... How paranoid do you get before you start tearing things apart?
Title: What would you do if your basement started smelling musty overnight?
Cutting into drywall chasing a musty smell is basically my nightmare scenario, but I’ve had to do it more times than I’d like to admit. Usually, I start with the floor drains and check for any pooling or slow drainage—sometimes it’s just a clogged trap holding water and stinking up the place. Had one job where the smell turned out to be from an old, forgotten utility sink with a dried-out trap. Took ages to figure that out.
I try not to go full demolition mode unless I’ve ruled out the easy stuff first. Sometimes it’s as simple as a loose pipe joint dripping behind the insulation. I’m probably more paranoid than most, but after seeing what mold can do, I’d rather tear up a bit of drywall than let it fester. Still, ripping things apart is always a last resort for me. Sometimes you get lucky and it’s just a blocked vent or a forgotten wet towel... but yeah, usually it’s something nastier.
I get the urge to rip stuff out right away, but honestly, I’d rather throw a dehumidifier down there and run an air purifier for a day or two before grabbing the drywall saw. Nine times out of ten, it’s just humidity or a minor leak—not worth turning the place into a construction zone unless you’re sure. Had a tenant once who freaked over a musty smell, turned out they’d left wet boots in the utility closet. Sometimes it’s the simple stuff.
Title: What would you do if your basement started smelling musty overnight?
Nine times out of ten, it’s just humidity or a minor leak—not worth turning the place into a construction zone unless you’re sure.
That’s a fair point. I’ve seen folks go straight for demo when a little patience and observation would’ve saved them a lot of hassle. Before anyone grabs a saw, I’d suggest a step-by-step approach:
1. First thing I’d check is the obvious—anything wet or damp left behind, like those boots you mentioned. Sometimes it’s just a forgotten mop bucket or a pile of laundry.
2. Next, I’d run my hand along the baseboards and lower walls to feel for any cold spots or dampness. If there’s moisture, that could point to a leak or condensation issue.
3. After that, I’d look at the HVAC setup. Is the basement getting enough airflow? Sometimes closed vents or blocked returns can make things musty fast.
4. If nothing jumps out, I’d set up a dehumidifier and monitor the humidity levels for a day or two. Anything above 60% is asking for trouble.
5. Only if I see visible mold, persistent wet spots, or water stains would I start thinking about opening up walls.
I get why people want to act fast—mold can be nasty—but tearing into drywall without knowing the source can just make things worse (and more expensive). Out of curiosity, has anyone here actually found a hidden leak after just a musty smell? Or is it usually something simple like humidity or forgotten wet stuff? Sometimes I wonder if we overthink these things...
