- Put in two of those metal mushroom vents on my shed last fall.
- Was kinda skeptical at first—cutting into the roof freaked me out, and I kept second-guessing if I’d sealed everything right.
- Used asphalt shingles, so I followed the instructions and did a bead of caulk under the flange, but skipped the extra roofing cement. Maybe I’ll regret that?
- Winter here (central Wisconsin) was rough—lots of snow, some ice buildup. No leaks so far, but I keep checking after every big melt just in case.
- Noticed the screws on one vent were a little loose this spring. Tightened them up, but now I’m wondering if I should’ve used longer fasteners or something with a gasket.
- Honestly, the plastic ones looked easier to install but felt super flimsy in person. Metal seems sturdier, but I’m still not 100% convinced they’ll last forever.
- Anyone else get condensation issues inside the shed after installing these? Mine’s better vented now, but still gets damp on cold mornings... not sure if that’s just normal or if I messed something up.
I actually went with the plastic vents on my shed last year, even though they felt pretty cheap in the store. I get what you mean about them seeming flimsy, but I was on a tight budget and figured if they lasted 5-10 years, I’d call it a win. So far, no leaks, but we didn’t get as much snow as you did up in Wisconsin.
About the condensation—honestly, I still get some dampness inside in the mornings too. I’m not sure it’s something you can fully avoid unless you insulate or add a vapor barrier. The vents help, but sheds just seem to sweat a bit when the temps swing fast, especially with metal or plastic roofs.
One thing I did differently: I used longer screws with rubber washers, and that seemed to help keep things tight through the winter. Might be worth swapping those out if you’re worried about leaks down the line. Roofing cement is messy and expensive, so I skipped it too… fingers crossed that doesn’t bite me later.
Roofing cement is messy and expensive, so I skipped it too… fingers crossed that doesn’t bite me later.
I get wanting to avoid the mess, but honestly, a dab of roofing cement around the vent base has saved me more than once—especially after a couple freeze-thaw cycles. Those rubber washers help, but they can dry out or crack over time. Ever try using a bit of flashing tape under the vent flange? It’s not as messy as cement and gives some extra peace of mind. Just seems like with plastic vents, any extra layer helps in the long run.
I hear you on the mess factor—roofing cement is a pain to work with, especially if you’re trying to keep things tidy. But I’ve had a couple of those mushroom vents start leaking after a few years, and every time it was where the plastic met the shingles. The washers just didn’t hold up through our Midwest winters.
What’s worked for me: I’ll run a thin bead of cement under the flange, press it down, then add flashing tape around the edges. Not pretty, but it keeps water from sneaking in if the washers fail or the plastic warps. I’ve also tried skipping the cement and just using tape, but after a couple seasons, I noticed some seepage—maybe our freeze-thaw cycles are rougher than most.
If you’re in a milder climate, maybe you can get away without the cement, but up here, I’d rather deal with a little mess than have to patch leaks down the road. Just my two cents...
I’ve had similar issues with those vents on my shed roof—plastic just doesn’t seem to hold up once winter hits hard. Tried skipping the cement once, thinking tape would be enough, but ended up with a soggy ceiling after a couple freeze-thaw cycles. Honestly, the mess is annoying, but I’d rather scrape off a little extra cement than deal with water stains and mold later. If you’re somewhere that gets a lot of snow and ice, I’d say your method is spot on.