What Vent to Use?

Roofing/Construction Questions
1

Good Afternoon,

The kids and I are roofing my house and I have run across an issue I can’t seem to find an answer for. I have a 3:12 roof that runs up against a `10:12 roof. For the 3:12 I am planning on using the existing eave vents for intake, but I am at a loss on what to use for exhaust venting (prior roof had none) for the 3:12, as well as intake for the 10:12. A ridge vent does not seem to be an option as there is no ridge, the roof simply stops where the higher roof starts. The higher roof (10:12) has no attic to speak of, just fasters (cathedral ceiling) so the only option I can think of is an edge intake vent. Any ideas would be most appreciated. Thanks!

2

Depending on how it is framed you may be able to use vented drip edge at the uppermost part of the roof.

Barring that I would recommend a shingle over intake vent like the Edge or Smartvent for exhaust.

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3

If you have an attic, you can use gable end type at the transition. Hi-jacker box vents for cedar shake roofs might work also.

4

Lomanco Vents - Omni Wall should work for the lower roof.
But if there is a regular attic,standard roof vents could be used as well.

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5

Ha! I built one of those 39 years ago for a flat entry into an office building.

6

I’ve used it once or twice,seems to work as well as any homemade solution.

7

Yes, I thought those may be my two options for intake on the upper roof. which design do you use most often?
Thanks,
john

8

Hi, thank you for your response. The upper roof (10:12) has no attic, just rafters. I thought we’d go with a ridge vent on the top, but intake may be a problem. Someone has suggested a drip edge vent and that may work. kind or messed up how it was built, exhaust from lower and intake for upper right next to each other :slight_smile:

9

Post a pic of the transition. Do you have ice damming problems in the winter?

10

Thanks for that, do you mean the box type vent? There is not much of an attic even on the lower roof at that section of the ridge, it’s just one foot.

11

that’s what we have here, only going up to the cathedral roof, looks like an add on but I am not sure. It’s a cabin like home near Mt St Helens in WA State.

12

the lower attic ridge at that point is only one foot.

13

Okay, this is my first year, my wife bought the house while I was teaching out of state. Does not get a lot of snow. I’ll go snap a photo and post it. Thanks.

14

Here is an older photo, it’s tarped just now due to rain. Thanks, everyone for help, tried to get an opinion at home depot but was not successful

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20200813_2036134000×2250 1.73 MB
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15

The guy you asked at H.D. was running the deep fryer at McD’s last week!

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16

:smile:This is true!

17

If it’s a continuous roof that starts at the lower roof and continues to the ridge of the upper roof could I just use the eave vents and a ridge vent at the top of the steep roof? All of the bays seems to be connected.

18

Sure, if the bays are connected that would be fine.