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.
- 1Using an air admittance valve (AAV)
- 2Venting out a wall instead of through the roof
- 3Brainstorming various combinations of ridge vents, powered fans, and gable vents
- 4Considering adding soffits or edge vents
In their words
Unedited, most upvoted first, 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 ↗
“I see homes without roof vents. We also have a steel roof and I would prefer not to deal with that. How can this be accomplished? Air admittance valve?”source ↗
“It was suggested to vent out a wall. Have not seen this done before.”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 route roof drainage without underground pipes
- 2Are powered attic roof vents actually worth it?
- 2How to safely remove old house wiring during a renovation
- 2Roof vents installed off-center and poorly aligned
- 2How to fill deep holes in the yard from removed structures
- 3Roofers left mono roof top exposed without a cap