This allows cool dry intake air.
Rusty nails in roof vents.
At the house eaves blocking was nailed between or against the ceiling joist ends.
Insulation rusty nails or rust spots that dripped onto your insulation blackened plywood mold or mildew inside your attic curling or cracking shingles uneven snow melt and icicles.
The good thing to know is that some rust will not necessarily cause you to have the vent replaced.
Intake vents low at the roof s edge or in the soffit eaves along with exhaust vents high on the roof at or near the ridge.
All of those things will add to the moisture in the attic and will rust any metal exposed there.
When dealing with chemicals in products such as roofing cement and rust resistant primer and.
Another thing to check is weather or not something else is venting to the attic space that shouldn t be such as a dryer vent kitchen hood vent or bathroom exhaust fan.
The nails might have popped.
Over time your roof vent may become rusty.
However they can cause leaks particularly if you have an asphalt shingle roof.
Roofing nails are galvanized but add enough moisture and galvanized nails.
Spot vents on lower roof slopes or power vent fans are not as good a substitute for the year round passive venting provided by a ridge vent.
Take a visual on all of your roof vents whether they are ridge vents or mushroom or static vents to see if it looks like they may be allowing precipitation in your attic.
If you find this then you need to look further into improving your attic ventilation performance.
Check inside your attic for mold stains and rusty nails.