Attics usually have a passive ventilation system in which outside air comes in through the soffit eave vents at the bottom warms up in the attic and escapes through the can or ridge vents at the top because hot air rises.
Attic fan mold.
This is why mold resistant insulationis so important in an attic.
Mold needs 3 things to grow.
If you find black spots in your attic and you are thinking it could be harmful black mold you do not necessarily need to panic.
Moisture food and warmth.
Dark black staining on wood surfaces in the attic.
Attic mold loves wet insulation.
Mold located on ductwork on roof decking trusses or just about anywhere in the attic is simply a problem of excessive moisture.
High humidity in a space like an attic can lead to mold and a spill in a carpeted area of your home that isn t quickly taken care of can also lead to mold under the carpet.
Mold will survive in almost any environment that is the right temperature has moisture even in the air and has something for food e g.
In fact it often times take only 12 hours for certain types of insulation to start growing mold.
Dryer vents plumbing vents kitchen or bathroom fans vented into the attic.
If you eliminate just one of these elements mold will starve and die.
No air sealing an attic will reduce the likelihood of moisture entering the attic.
The only potential downside of air sealing is the increased humidity inside the home.
Related to 3 above this practice can pump warm moist air into the attic where it can be trapped and begin the cycle of mold growth.
This can be easily addressed by increasing your ventilation via your bathroom fans.
Causes of mold while damp and warm climates are a prime breeding ground for our fuzzy friend other conditions that bring mold include lack of ventilation and proper sheathing.