Every fall the subject of condensation comes up due to the
cooling outside temperatures. So are the drips really from condensation...or is there a new roof leak? Owners of vintage homes, like above, ask, "How to stop condensation from a metal roof?"
1. If there is a roof leak, the drips show up ONLY on rainy days
and usually within 10 minutes. They stop when the rain stops. Water does not sit
somewhere and then decide to fall several days later.
2. Repairing or sealing
roof venting sites, either planned or informal, will only increase condensation
because moist air is trapped.
3. Leaks and condensation BOTH can be a
problem; leaks dampen the interior insulation which increases the condensation.
In short there may be more than one problem to deal with.
4. Old chimney
bricks and wood can absorb water; pouring a glass of water on these areas is a
good check--if the water does not spot like a new wax job on a car, then the
brick/wood is absorbing water. And both can absorb a lot of water.
5.
Condensation can be so severe, the moisture can drip as a steady stream.
6.
Finally, controlling condensation can be tricky--never eliminated, just managed.
Common sense tips
Circulate air, and keep the fans on. The more the fans are on, the less condensation will appear.
Install roof vents to allow the warmer interior air to escape.
Try dehumidifiers to remove moisture from the air. Even running the compressors of your AC units could help.
Check your lighting and heating devices. Some versions of these devices affect the air temperature less. An oil heater located just under a metal panel is guaranteed to generate condensation.
Consider metal roof vapor barrier work.
Condensation is an interior concern, not a roofing problem. Yes, there may be roofing issues but the management of condensation cannot be resolved entirely by working on top of a roof.
I remember...on a truly-crisp morning, a lady, who owned a beautiful old home with a vintage tin roof, escorted me upstairs to her attic for a roof inspection. She turned on one light bulb. Within five minutes, our conversation and the light bulb were causing small drips on nearby panels. Just as condensation under metal roofing originates from inside the structure, the management of its severity is located inside the building.