You finally get home to relax, kick off the shoes
Where Is The Stain?
If the ceiling stain is around a trapdoor or air vent, then it's more than likely that they have been caused by some kind of moisture. Once the moisture takes hold, bacteria sets in and
spreads out into menacing shapes and stains. If the stains are really dark and look more like streaks than drink-spills, then the problem could be dirt. When was the last time you cleaned the air filter or had the furnace serviced?
Also, is the dark stain on the ceiling right above where you often burn candles and nowhere else on the ceiling? It's very possible that the stain isn't dangerous mold but is a permanent discoloration caused by burning candles at that spot. Sooty dark stains can often show up on the ceilings of rooms with fireplaces. They can usually be cleaned off with plain soap and water.
And, are there any smokers in the home? Usually, people who smoke have a few preferred places to sit and smoke, if they smoke inside the home. They can often leave some ceiling stains that generally fade around the stain's edge. These can vary in color from a light tan to black coffee. These also can be cleaned with soap and water.
What About Mold?
The big fear whenever a ceiling stain creeps up is that the stain is caused by mold, which can potentially weaken the ceiling structure. The moisture gets in usually through either a roof leak or a problem in the ceiling where condensation is not drying out as it should. Although there are a lot of products sold that can fix the stain, they won't get rid of the mold.
So, how can you tell if there is a roof leak or condensation problem in the roof causing the stains? Usually, roof leak stains will be located in the edges of fixtures like lights or fans or even the edges of ceiling panels or tiles. Condensation stains usually come in groups, so that your ceiling suddenly turns into an Appaloosa horse.
The big problem now is to find the leak, fix the problem and then work on cleaning the ceiling stains.