How to vent a plumbing system or attic without cutting into a roof
You can vent plumbing through an exterior wall using an air admittance valve instead of a traditional roof penetration. For attic airflow without roof cuts, options include edge vents or low roof intake systems when soffits are missing, alongside wall-mounted or gable alternatives.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
Found another way around this?
Share your steps and trade-offs so fellow engineers don't have to reinvent the wheel. No account required.
- 1Using an air admittance valve (AAV)Did this help you?
- 2Venting out a wall instead of through the roofDid this help you?
- 3Brainstorming various combinations of ridge vents, powered fans, and gable ventsDid this help you?
- 4Considering adding soffits or edge ventsDid this help you?
In their words
Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.
“The powered roof vent fan is not currently working, but could be replaced. There are no soffits.”source ↗
“The attic does seem hot, so trying to improve ventilation without going too wild on cost.”source ↗
“Since you don’t have soffits, I’d also ask about a low roof intake vent/edge vent system.”source ↗
Where this came up
People with this problem also raised
- 2How to fix the roof after removing a chimney
- 3How to route roof drainage without underground pipes
- 4How to ventilate an attic with no open soffits?
- 4Can I remove these framing supports without compromising stability?
- 2How to vent a ceiling bathroom fan through a snowy roof
- 2How to add a vent when you can't reach the stack