didn’t factor in how much they’d block airflow. Ended up with condensation dripping in winter—total pain.
That’s exactly what happened to my uncle’s shed, except he got mold behind the insulation too. He was convinced trusses were the way to go for easy install, but didn’t realize how much more you have to think about venting with them compared to open rafters. I always thought vents were just for summer heat, but the winter condensation is honestly worse.
Did you try adding any extra vents after you noticed the problem? I’ve seen some people cut in gable vents or even add those little roof turbines, but I’m never sure how much difference they actually make unless you really open things up. Wondering if anyone’s had luck retrofitting better airflow after the fact, or if it’s just one of those “live and learn” situations.
I’ve actually dealt with this in a detached garage I insulated a few years back. Trusses definitely made the build easier, but I underestimated how much they’d mess with airflow. I started with just soffit vents, thinking that’d be enough, but once winter hit, I had the same condensation issues—water spots on the ceiling, and insulation getting damp near the eaves.
I tried adding gable vents after the fact, which helped a bit, but honestly, it wasn’t a night-and-day difference. The real improvement came when I put in a couple of those spinning roof turbines. They’re not pretty, but they move a surprising amount of air, especially if you’ve already got some lower intake vents. Still, if the insulation is packed right up against the roof deck or blocking the airflow paths, even extra vents won’t fix everything.
One thing I wish I’d done from the start was use those foam baffles between the trusses to keep the air channel open above the insulation. Retrofitting them after everything’s in place is a pain, but it made a noticeable difference for me. Mold never got out of hand, but I did have to replace some soggy insulation.
Curious if anyone’s tried those powered attic fans in a shed or garage? I always hear mixed things—some folks say they just pull conditioned air out of the building, others swear by them for keeping things dry. For me, passive venting plus making sure the airflow isn’t blocked has been the most reliable combo, but I’m not convinced there’s a one-size-fits-all answer. Climate probably plays a big role too—winters here (Ontario) are brutal for condensation.
Trusses are a blessing and a curse, right? I’ve had a few garages where I thought I was a genius for using them, then spent the next winter cursing at the condensation. Those foam baffles are a pain to retrofit, but man, they’re worth it. Powered attic fans? Tried one once—felt like it just sucked my wallet dry on the electric bill and didn’t do much else. Passive venting and keeping those air channels clear has been my go-to ever since. Ontario winters don’t mess around.
Trusses seemed like a no-brainer for my workshop—fast, cheap, and strong. But yeah, the first winter, I got those nasty drips from condensation. Ended up crawling around with foam baffles and a staple gun, cursing the whole time. Passive vents and making sure the soffits stay clear have been way more reliable than any fan I tried. Ontario cold just finds every weak spot, doesn’t it?
Trusses definitely make things go up fast, but yeah, condensation’s a pain—especially once the temps drop. I ran into the same thing last year on a garage build. Thought I’d done everything right: vapor barrier, insulation, the whole deal. Still got those drips forming on the underside of the sheathing. What finally helped was a combo of steps: first, I made sure every soffit vent was totally clear (had to pull out some insulation that’d shifted), then I added ridge vents. The passive airflow made a bigger difference than I expected.
One thing I learned the hard way—if you’re using batt insulation, don’t jam it right up against the roof deck. Leaving that little air gap with baffles is key, even if it’s a pain to install. Fans just seemed to move the problem around for me, not solve it. Ontario winters are brutal for finding every shortcut you take... Next time, I might try a continuous vapor barrier taped at every seam, but I’m still not sure if that’s overkill for a workshop.
