Telltale Signs of Water Damage
“Sweat” stains - If it looks like there is a darker shade of your paint on your ceiling, you most likely have the start of a water leak. This causes a sweat-like appearance on your ceiling and you should take action before it gets worse.
Water stains - Usually brown in color, water stains mean there is a leak or there was a leak. Water stains will usually happen from a leaky roof, overflowing of sinks, tubs, and toilets on the second floor, and cracked pipes.
Ceiling Bubbles - If you notice your ceiling swelling or bubbling, there is a buildup of moisture in the drywall.