I ran into something similar last fall—kept sealing over soft spots, but they just came back. Turned out the joists underneath were rotted from years of trapped moisture. I’d missed it at first because the boards looked fine on top. Once I pulled a few up, it was obvious. Now I always check underneath and make sure there’s airflow before patching anything. It’s a pain, but saves a ton of hassle later.
That’s a good call on checking underneath. I used to just eyeball the surface too, but after getting burned by hidden rot once, I started using a small awl or screwdriver to poke around for soft spots. If the tool sinks in easily, there’s usually trouble below. Also, if you notice any musty smell, that’s a red flag for trapped moisture. It takes a little extra time, but catching it early definitely beats ripping out half the floor later.
If the tool sinks in easily, there’s usually trouble below.
That’s spot on, but I’d add—sometimes even if it *doesn’t* sink in, you’re not totally in the clear. I’ve seen plywood that felt solid but was delaminating underneath from years of slow leaks. Tapping around with a hammer can help too—hollow sounds are a giveaway. And yeah, that musty smell? Nine times out of ten, it means you’re already late to the party. Moisture hides in places you wouldn’t expect, especially if someone slapped a coat of paint over the problem. Always pays to be a little paranoid when checking used stuff.
Moisture hides in places you wouldn’t expect, especially if someone slapped a coat of paint over the problem.
That’s the truth—paint’s just a band-aid for rot. I’ve seen folks get burned thinking a fresh coat means “good as new.” Your point about being a little paranoid is solid. It’s not overkill, it’s just smart. I’d rather spend an extra ten minutes poking around than end up with a pile of junk later. Trust your nose and your gut—if something feels off, it probably is.
Paint’s like makeup on a zombie—looks good till you poke it. I always tap around with a screwdriver, especially near seams or corners. If it feels spongy or you hear a crunch, that’s trouble. Trust me, your nose knows... musty means money.