I'm in the process of installing an upstairs laundry room, and I'm looking to vent the dryer to the roof. The route to an outside wall is almost 25 feet, with a few turns, whereas the route to the roof is roughly 8 feet from the dryer - so I think the roof is the best option.

My question is, what should I look for in a roof vent? I'm in an area that gets a fair amount of snow in the winter (a few snowfalls over 1ft each year). I'm planning on using all solid pipe, and insulating the pipe in the attic all the way to the vent, and keeping the vent higher up on the roof to prevent ice damming.

What should I look for in the roof vent itself?

  • No mesh that would collect lint
  • Low back pressure
  • Metal or plastic?
  • High or low profile?
  • Anything else I'm missing?
  • What type of actual roofing material?
    – Paul Logan
    Commented Nov 20, 2017 at 5:24
  • where do you live? Climate plays a part in it. Also, what Dryer model are you using? (while local codes often prohibit 25'+ runs, they also defer to manufacturers installation instructions and their allowances). I recently had to solve a similar problem, in the end, I opted for the 33' run, out the gable
    – noybman
    Commented Nov 20, 2017 at 6:08
  • The roof is asphalt shingles; we’re near Cleveland, Ohio; the dryer is a newer Samsung DVE45M5500 model
    – kponz
    Commented Nov 20, 2017 at 12:28

1 Answer 1


If you truly have significant snow accumulation then you need the following: Start with the thinnest walled 4" diameter PVC pipe you can get your hands. Check the irrigation supply companies; Class 100, & Class 125. Terminate it about waist high directly behind where the dryer will sit, against the wall. Use 4" flexible vent material to go from the dryer to this PVC pipe. Extend the PVC pipe through the ceiling of the laundry room and then on through the attic and through the roof line, securing along the way as necessary. Avoid any unnecessary bends. Using 22*bends or at the most 45*bends, off-set as necessary in the attic to avoid framing members. I would extend through the roof about 2-feet. Flash the pipe at the roof line with a standard 4" plumber's type rubber boot roof flashing. Make sure it goes under the shingles. On the top of this vent pipe install a rain cap or is sometimes called a china cap. Select a cap with lots of venting space. Eliminate any and all screen material. I like a product made by Award Metals. They call it their 'Type B' china cap.

  • Where were you when I posted the same question? I live in Buffalo NY, so I'm rather confident 2' wouldn't be enough. My question here is that PVC (I thought) was not allowed by many codes, so if this path is chosen, why opt for PVC vs. 4" metal?
    – noybman
    Commented Nov 22, 2017 at 1:31
  • The reason being that the roof flashing with the rubber boot has been used successfully for time immemorial, virtually leak free. The metal vent material has a seam down the length that will be hard to seal. The PVC will never rust above the roof line. The metal will.
    – Paul Logan
    Commented Nov 22, 2017 at 18:06
  • If you live in Buffalo NY then God Bless you. If you live in Buffalo NY then whenever you are in the midst of one of the many winter snow events you have to run the dryer periodically to keep a hole melted, and still I say God Bless you. (I lived in Idaho Falls, Idaho for a couple of years.)
    – Paul Logan
    Commented Nov 22, 2017 at 18:13
  • I wasn't trying to hijack the thread, but the note on rust vs. non rust makes sense however when I was working this issue for the house I just bought, it was clearly identified to not use PVC due to the inherent static buildup possibility + of course lint = possible fire in a melt-able material. So I never pursued it farther, but I noticed numerous comments that it was against code, (or more appropriately, code says use metal rigid duct... thereby excluding pvc). I like Buffalo, but indeed, 2' wouldn't cut it ;)
    – noybman
    Commented Nov 23, 2017 at 3:14

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