This is why you rarely find mold growth in the attic above a garage or a rarely used portion of the home.
Mold in attic above bathroom.
Notice how the dark line on the insulation in the photo below line up with the top plate.
This is a different perspective from the other video about bathroom fan venting causing mold.
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.
Mold needs 3 things to grow.
Matte and other low sheen paints absorb much more moisture which in turn leads to mold growth.
Dryer vents plumbing vents kitchen or bathroom fans vented into the attic.
Moisture food and warmth.
Mold species such as stachybotrys chartarum which looks like slimy growth loves attic basement bathroom and space under the sink black mold can also grow behind the walls or attic ceilings completely undetected until the occupants smell the presence or experience health problems.
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.
If you eliminate just one of these elements mold will starve and die.
The most common cause of attic mold by far is blocked or insufficient ventilation of the attic space.
Paint the bathroom ceiling with a high sheen gloss paint.
Http youtu be pne imqvfoy it shows the things we noticed to d.