You’re not alone—those meters can be finicky, especially the pinless ones. I’ve had similar “is this thing for real?” moments. Honestly, nothing beats crawling around and getting hands-on. The thermal cameras are fun but, in my experience, they’re better for spotting drafts than moisture. Still, if it saves you from insulation rash even once, maybe worth a shot. And yeah, the screwdriver test is old-school but reliable... sometimes simple really is best.
I’ve run into the same thing with pinless meters, especially on older decks where the wood density varies a lot. I’ll usually start with a meter just for a quick scan, but honestly, I don’t trust it until I’ve poked around with a screwdriver and checked for soft spots by hand. Sometimes I’ll even pull a couple of boards if I’m not convinced. Thermal cameras are neat, but like you said, they’re more useful for finding cold spots than actual moisture. For me, it’s a mix of tools and just getting down there to see what’s really going on.
I’m right there with you on not trusting pinless meters 100%, especially on older decks. I’ve had readings jump all over the place just because of a knot or a denser patch of wood. My process is pretty methodical—first, I’ll do a quick scan with the meter, but then I go board by board with a screwdriver or even a small awl. If anything feels even a little spongy, I’ll pry up that section to see what’s going on underneath. Sometimes it’s just surface weathering, but I’ve found hidden rot more than once that way.
One thing I’d add: I like to check the joists and ledger board too, not just the decking. Had a situation last year where the deck boards looked fine but the ledger was starting to go soft—wouldn’t have caught it without poking around underneath. And yeah, thermal cameras are cool, but unless there’s a big temp difference, they don’t always tell you much about moisture in wood.
For me, it’s all about layers—meter, hand tools, visual inspection, and sometimes just trusting your gut if something seems off. It takes more time, but I’d rather catch problems now than after the underlayment’s down.
That’s pretty much my approach too—layers of checking, not just trusting the gadgets. I’ve found pin meters can be a little more reliable than pinless, but you’re right, nothing beats poking around with a screwdriver. Had a deck last fall where the joists looked perfect from above, but underneath there was a patch of soft wood right at the ledger. Easy to miss if you don’t crawl under and check. It’s tedious, but worth it in the long run.
I get the appeal of crawling under and poking around, but honestly, I've never been a fan of going full detective mode unless there’s an obvious issue. Maybe it’s just me being cautious with my time and knees, but I lean on the tools more than most folks here seem to. Pin meters, even the cheaper ones, have saved me from pulling up way more boards than necessary. Sure, they’re not perfect, but I’ve found if you check a few spots and the readings are consistent, it’s usually good enough—especially on a deck that’s only a few years old.
That said, I do agree about not trusting gadgets 100%. I’ll do a quick tap test or use a screwdriver if something feels off or the meter gives weird numbers. But for me, crawling around every time just isn’t practical—especially when you’re trying to keep costs down or working solo. Maybe if I had a history of rot in one area, I’d be more thorough.
One thing I do that’s maybe not standard: I use a cheap inspection mirror and flashlight to peek under from the sides before committing to anything more invasive. It’s not as good as getting under there, but it catches most of the obvious stuff like soft patches or water stains. Plus, saves my back.
I guess it comes down to how much risk you’re willing to take. For me, as long as there’s no visible sagging or weird smells, and the meter checks out, I call it good. If something seems off later, then I’ll dig deeper... but so far, haven’t had any disasters doing it this way.