Humidity gauges are handy, but honestly, I’ve seen them give folks a false sense of security. Sometimes the attic looks fine on paper, but there’s still hidden condensation or mold. I’d say nothing beats actually crawling up there and checking for frost or damp spots, especially after a cold snap. Also, about those bathroom fans—totally agree, but I’ve also run into kitchen vents dumping into attics. That one’s a mess if you cook a lot.
You nailed it—humidity gauges can be helpful, but they’re definitely not the whole story. I’ve seen folks get lulled into thinking everything’s fine just because the numbers look good, only to find mold or frost hiding out in the corners. I always tell people, if you’re able, pop your head up there after a cold snap or big storm. Look for any shiny spots or dark patches on the sheathing. Sometimes you’ll even spot a little frost on the nails, which is a dead giveaway.
About those vents—couldn’t agree more. Bathroom fans get a lot of attention, but kitchen vents dumping into the attic are sneaky culprits too. I once found a thick layer of greasy dust up there from years of cooking steam venting straight into the insulation... not pretty, and it made the moisture problem way worse.
If you’re dealing with ice dams, it’s usually a combo of heat loss and moisture, so tracking down where that warm, damp air is sneaking in is half the battle. It’s not always obvious on paper, but a hands-on check can save a lot of headaches later.
Had to laugh a little reading about the kitchen vent—I found out the hard way that ours was just dumping steam right into the attic too. Didn’t even cross my mind when we moved in. First winter, I noticed a weird smell upstairs and spotted these tiny beads of water dripping from some nails poking through the attic boards. I thought it was a roof leak at first, but nope... just warm air and cooking steam sneaking up there and freezing on cold nights.
Took forever to figure out where it was coming from. Turns out, that vent pipe just stopped short—never made it outside. Wild how something so small can cause such a mess. We ended up running a new vent all the way out and added more insulation over the bathroom too (that fan was barely doing its job). Haven’t had any ice dams since, knock on wood, but I still get nervous every time we get a big snow.
I agree—just looking at gauges or numbers never tells the whole story. Sometimes you gotta crawl around up there and see for yourself... even if it’s not much fun in January.
Not to nitpick, but running the vent all the way outside doesn’t always solve everything, especially in older homes with odd rooflines or tight attic spaces. I’ve seen cases where even after rerouting vents, folks still had condensation issues because of insufficient air sealing or gaps around recessed lights and attic hatches. Insulation helps, but if there’s still warm air sneaking up, it’ll find its way to the roof deck and cause trouble. Sometimes a thorough air sealing job does more than just piling on more insulation. Just something to keep in mind—every house is a bit different.
