Rotted roof decking and mold around chimney
Storm leaks often reveal widespread mold and rotting wood surrounding chimneys and vents. Roofers frequently blame this extensive mold on poor ventilation, which forces homeowners to figure out how to improve airflow. This creates concern over whether contractors will fully replace the compromised decking left directly above the chimney.
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.
- 1Replacing rotted decking and expecting specific materials like copper flashing for the costDid this help you?
- 2Adding soffit, ridge, or gable vents.Did this help you?
- 3Installing baffles between rafters to keep insulation from blocking airflow.Did this help you?
- 4Spraying the decking with a bleach solution or Borax in hot water to kill the mold.Did this help you?
- 5Ensuring bathroom exhaust fans vent completely outside the attic.Did 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.
“Had a leak after a recent storm which led to the mold discovery.”source ↗
“The mold is not just contained to the decking in the photo. It is widespread.”source ↗
“One roofer said that the mold is because I don’t have enough ventilation. How do I improve ventilation and deal with the mold?”source ↗
“My main concern is the decking left directly above the chimney. The scope of work calls out for “Rotted decking surrounding chimney and septic vent to be replaced””source ↗
Where this came up
People with this problem also raised
- 3Exposed wood corner where new and old roof meet
- 2How to fix the roof after removing a chimney
- 8Ceiling popping noises and drywall screws showing after roof repair
- 4Why is the plywood roof decking sagging on my new house?
- 5Is a gap in roof sheathing at the ridge okay before shingling?
- 30HVAC lineset leaking through the roof