The outer surface is not the only place brown mold can grow.
Brown mold spots on ceiling.
Walls are also common habitat for brown mold to grow especially in damp or dark spaces such as ceiling room and basement.
If left unchecked brown mold can grow thicker taking on a fuzzy or even hairy appearance.
Brownish spots on the ceiling can be fluids gross i know from the bugs.
Left untreated the mold stain may grow and become darker over time.
How to safely clean mold off of a ceiling.
Mold is often dark but it can come in other colors.
Cigarette smoke can cause staining via the same principle as ghosting.
Some species of brown mold may even grow into thicker mushroom like blobs.
Your best option for a base coat to cover water stains on the ceiling is an oil based mold resistant stain blocking primer in a shade closely matching that of the existing ceiling.
Sometimes the water droplets dry out and only leave behind the stains while in other cases the dripping seeps through the ceiling and you have a leaky ceiling with brown stains.
Mold damage aside from water damage mold growth on your ceiling is also a likely cause of the brown spots.
Depending on the colour of the surface it is growing on it may appear brown or nearly black.
In this case it was due to areas of missing insulation in the attic.
I suggest you call an exterminator.
Ceiling stains can draw eyes away from even the most beautiful living room dining or kitchen.
The soot attaches to cold spots on the ceiling.
The spots also may be mold.
Cleaning soot from ghosting is extremely hard.
Typically your only recourse is to repaint.
In early stages brown mold may look like spots or discolouration.
Mold may not seem very threatening but the danger.
There are 3 most common types of ceiling stains and they are 1.
Ceiling mold growth is typically black.
We had a wasp problem a while back and the exterminator asked if there were any brown spots on the walls or ceiling explaining that this is a sign of infestation.
The second cause of ceiling discoloration may be related to moisture but is not directly caused by it.
To test for mold touch the spots with a cotton swab that has been dipped in household bleach.
If there is plumbing problem that happens inside the wall structure mold will grow from the inside and slowly spread to the outer part if not removed.