“I did have to re-tighten a couple screws after the first big thaw—guess the wood shrunk more than I expected.”
That’s spot on—wood movement up here always catches folks off guard, especially after a hard winter. I make it a habit to run through all my exterior fasteners every spring. Even pressure-treated stuff moves more than people expect.
On the mushroom vents, I’ve had similar results. They’re not flawless, but you’re right: ventilation is noticeably better than with the old square styles. I do agree about snow buildup—had one vent get iced over last February and it backed up moisture into the shed. Ended up adding a little foam baffle just inside, which wasn’t perfect, but helped keep airflow moving.
Butyl tape under the flange is a solid move. I’ve tried both butyl and polyurethane sealants, and butyl seems to handle the expansion/contraction cycles best, especially on rough OSB like you mentioned.
Improvising with what you’ve got on hand often works out better than over-planning. There’s something to be said for just getting it done and adjusting as you go.
That foam baffle trick is clever—I’ve seen folks use everything from mesh to old furnace filters to keep the airflow up without letting snow drift in. I’ll admit, I’m still partial to polyurethane for spots that see a lot of driving rain, but butyl’s definitely easier to work with when temps swing. Curious if anyone’s tried adding a wind deflector or shield on the outside? I’ve wondered if that would help with the icing, or just make things worse by trapping more snow.
Curious if anyone’s tried adding a wind deflector or shield on the outside? I’ve wondered if that would help with the icing, or just make things worse by trapping more snow.
I’ve actually played around with a small sheet metal shield on the windward side of my shed vent. It did cut down on direct snow blowing in, but honestly, it also seemed to create a little eddy where snow piled up right at the base. Didn’t really help with icing either—if anything, it just made the melt/refreeze cycle worse. I’m with you on butyl being easier in the cold, though. Polyurethane’s great for sealing, but it’s a pain to work with when it’s below freezing.
Funny, I tried something similar last winter—thought I was being clever with a little plywood baffle on the vent. It blocked some wind-driven snow, but then I got this weird drift right under it and, honestly, more moisture hung around than before. I swear, half the time these “fixes” just move the problem somewhere else. As for butyl vs. polyurethane, totally agree—poly’s a nightmare to spread when it’s cold and you end up with gloves stuck together.
I hear you on the “fixes” just shifting problems around. I tried those mushroom vents on my shed last fall, hoping they’d cut down on condensation. They helped a bit, but I still get frost inside when it’s really cold. Has anyone managed to keep things dry without just making the shed draftier?