Funny timing, because I just had a debate about this with one of our contractors. He swears by 1/4" hardware cloth, but honestly, I think it’s a bit overkill unless you’re dealing with mice or bats. In my experience, 1/2" mesh still keeps out the bigger critters like squirrels and birds, and you get noticeably better airflow—especially when the humidity spikes. Haven’t had any break-ins yet, knock on wood. If you’re in a super wet area, I’d lean toward the bigger mesh and just keep an eye out for any tiny invaders. Sometimes you gotta pick your battles...
In my experience, 1/2" mesh still keeps out the bigger critters like squirrels and birds, and you get noticeably better airflow—especially when the humidity spikes.
That lines up with what I’ve seen on jobs around here. The 1/4" hardware cloth is solid if you’ve got a real rodent problem, but for most attics, 1/2" seems like a good balance. I’ve noticed it’s way less likely to clog up with dust or insulation too, which keeps the vents working longer without having to get up there and clean them out every season.
I had a client who went with 1/4" everywhere because the neighbor’s house had a bat issue. Ended up calling us back a year later because the attic was trapping so much heat and moisture, it started to warp some of the sheathing. Sometimes tighter isn’t always better.
Humidity’s a killer in my area too, so anything that helps airflow is worth considering. Just gotta keep an eye on those little gaps around the edges—sometimes the critters are sneakier than you’d think...
I get what you’re saying about 1/2" mesh being the sweet spot for airflow, but honestly, I’ve seen a few too many jobs where mice still found their way in through those gaps. Maybe it’s just the older homes around here or the fact that we’re close to a lot of open fields, but those little guys can squeeze through stuff you wouldn’t believe. I’ve had to go back and patch up more than one attic after homeowners thought 1/2" was “good enough.”
Yeah, 1/4" can slow down the venting a bit, but I’d rather deal with a little extra moisture than having nests and chewed wires. Cleaning out vents is a pain, but chasing rodents is worse (and way more expensive if they chew through something important). I guess it just depends on what’s causing the biggest headaches in your area. Around here, if folks don’t go tighter, they regret it down the line.
Curious if anyone’s tried a hybrid setup—like 1/4" where critters are a problem and 1/2" elsewhere? That’s something I’m thinking of pitching on my next job...
Hybrid mesh setups actually make a lot of sense, especially if you’re in mouse country. I’ve seen folks do 1/4" on the north side (where the woods are) and 1/2" everywhere else to keep things breathing. It’s not perfect, but it beats pulling out nests every spring. Ever tried layering mesh—like a fine screen over a coarser one? I’m not sure if it’s overkill or genius, but it’s crossed my mind after seeing what squirrels can do...
I get what you mean about layering mesh, but I always wonder if doubling up just makes it harder for air to move, especially in spots that already don’t vent well. I’ve seen folks do the fine-over-coarse thing, but then you get dust and junk clogging up the finer stuff way faster. Has anyone actually had luck with that long-term, or does it just end up being more hassle? Squirrels are a whole other level though... they’ll chew through almost anything if they’re determined.