Originally Posted by joecaption
Far better to just add a roof vent. A washing machine dumps a lot of water fast and needs a lot of incoming air.
The only times I've seen a roof vent leak is if someone lets a roof go way behond the time it should have been replaced and the old rubber seals have dryed out or someone reroofs and does not spend the extra $7.00 to replace the old vent boots.
Makes sense. Pretty much all of our roof vents leak, but that should be fixed as part of this reno. We've had our house for 1.5 years, and every time I do any investigation I'm shocked at the shortcuts previous owners took. Part of the problem is that it was a rental for years, and the owner was milking it. You should see the supply plumbing patchwork in the crawlspace....