To test for mold touch the spots with a cotton swab that has been dipped in household bleach.
Brown mold spots on ceiling.
Mold damage aside from water damage mold growth on your ceiling is also a likely cause of the brown spots.
Cigarette smoke can cause staining via the same principle as ghosting.
I suggest you call an exterminator.
The outer surface is not the only place brown mold can grow.
Mold is often dark but it can come in other colors.
There are 3 most common types of ceiling stains and they are 1.
Brownish spots on the ceiling can be fluids gross i know from the bugs.
Some species of brown mold may even grow into thicker mushroom like blobs.
The second cause of ceiling discoloration may be related to moisture but is not directly caused by it.
It may not have been mold.
The soot attaches to cold spots on the ceiling.
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.
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.
How to safely clean mold off of a ceiling.
When a portion of the ceiling stays damp for an extended period of time a yellowish brown mold stain can form overhead.
Ceiling mold growth is typically black.
If left unchecked brown mold can grow thicker taking on a fuzzy or even hairy appearance.
In early stages brown mold may look like spots or discolouration.
Left untreated the mold stain may grow and become darker over time.
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 spots also may be mold.
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.
Walls are also common habitat for brown mold to grow especially in damp or dark spaces such as ceiling room and basement.
Typically your only recourse is to repaint.
Ceiling stains can draw eyes away from even the most beautiful living room dining or kitchen.
Depending on the colour of the surface it is growing on it may appear brown or nearly black.
Once mold shows up on your ceiling it isn t long before a small patch evolves into a thriving colony.