Gut feeling has saved me more than once, especially when I’m looking at older appliances or HVAC units. Sometimes everything checks out, but something just feels off—usually turns out there’s a hidden quirk or repair waiting around the corner. Moisture meters are in my toolkit too, though I wish I’d started using them sooner. Ever have one give you a false positive because the wall was just cold from a draft? That threw me for a loop the first time.
The musty smell thing is tricky. I’ve had tenants panic over “mold” that turned out to be a dusty old filter or just stale air from a closed-up space. Tap test... yeah, still not convinced I’m doing it right half the time either. Do you find it works better on certain materials? For me, drywall’s easier than plaster, but maybe that’s just what I’m used to.
Caution’s definitely the way to go. I’d rather patch a nail hole than tear out a whole section looking for a leak that isn’t there.
I’ve definitely had moisture meters throw me off, especially in winter. Cold exterior walls can spike the readings, and it’s easy to overreact if you’re not careful. I started cross-checking with a thermal camera (just a cheap phone attachment) and that’s helped me avoid unnecessary patchwork. Still, sometimes I wonder if I’m just chasing ghosts.
The tap test is hit or miss for me too. Drywall gives a pretty clear sound difference when there’s a void or moisture, but plaster? That stuff’s all over the place—sometimes it sounds hollow even when it’s fine. I’ve read that older lath-and-plaster can have weird resonance because of how the wood dries out over decades. Maybe that’s why it’s so inconsistent.
Curious if anyone’s found a reliable way to distinguish between stale air and actual mold issues without going straight to air quality tests. I’ve tried running fans and swapping filters, but sometimes the smell lingers and it’s tough to tell if it’s just old house funk or something more serious.
- I hear you on the moisture meters—mine’s been all over the place in cold weather, especially near exterior walls. Sometimes I’ll get a high reading, cut open the drywall, and it’s bone dry. Learned to double-check before tearing into anything.
- For that stale air vs. mold smell, here’s what I do:
- Check for visible signs first—look behind baseboards, under sinks, around windows. Mold usually leaves some kind of mark or fuzzy patch.
- If it’s just a musty smell and no visible mold, I run a dehumidifier for a few days. If the smell fades, it’s probably just trapped moisture or old house funk.
- I’ve also used a cheap humidity gauge—if you’re above 60% indoors, that’s when I start worrying about mold.
- Sometimes I’ll tape a clear plastic sheet to the wall overnight. If there’s condensation behind it in the morning, you might have a hidden moisture issue.
- Plaster’s always tricky. I’ve had spots sound hollow for years with no problems. Unless you see staining or feel soft spots, I wouldn’t stress too much.
- Air quality tests are good but pricey. Most times, if you can’t see mold and humidity’s under control, it’s probably not a big deal. Old houses just have their own “aroma” sometimes...
- Gotta say, I’m a little more cautious about ignoring hollow plaster. Had a spot in one unit that sounded hollow for ages—looked fine, no stains, but eventually it crumbled and turned out there’d been a slow leak behind it. Sometimes you don’t get much warning, especially in older places with weird repairs over the years.
- On the air quality tests: yeah, they’re pricey, but I’ve had tenants super sensitive to musty smells. Sometimes it’s worth the peace of mind, even if you think it’s just “old house” odor.
- Those cheap humidity gauges can be all over the map too. I keep a couple in different rooms and average them out. Not perfect, but better than trusting just one reading.
Hollow plaster is like the roof’s version of a mystery leak—looks fine until it’s suddenly not. Had a ceiling once that sounded off when I tapped it, but I figured, “Eh, probably just old house stuff.” Fast forward a few months, and I’m patching a hole the size of a dinner plate after a slow drip finally made itself known. Lesson learned: trust your gut, not just your eyes.
On those humidity gauges, I hear you. I’ve got three in my attic right now, and they never agree. One says it’s the Sahara, another thinks I’m running a rainforest up there. Averaging them out is about as scientific as I get unless someone wants to sponsor me for a fancy monitor.
Air quality tests—yeah, they’re not cheap. But if you’ve ever had to explain to someone why their apartment smells like “old socks in a library,” you start to see the value. Sometimes it’s just peace of mind, sometimes it’s finding out you’ve got a mold party going on behind the walls.
Curious—anyone ever use those infrared cameras to spot hidden leaks or insulation gaps? I borrowed one once and felt like a ghostbuster, but it actually helped me find a cold spot where water was sneaking in around a vent. Not sure if it’s worth buying one, though, or just renting when things get weird.
