A trickle from your ceiling and bubbling paint and plaster; is it really a concern? It should be. Even something somewhat minor like this can lead to something much worse. In fact, there is a lot more that you do not want and do not want to happen if you leave this "minor" water damage unchecked.
Guess how many bug pests are attracted to areas damaged by water or saturated by water in your home? Go on, check. Are you creeped out yet? You should be.
Millipedes, centipedes, phorid flies, termites, and yes, cockroaches all love water damage. It opens up your home to some serious infestations of these disgusting creepy-crawlies and flying bugs. What is even more obnoxious is the fact that once these bugs infest your home and cost you thousands in pest control services, you end up with a wave of predatorial creatures that follow these insects into your home, namely spiders. The worst of the spiders is the brown recluse, which definitely loves rot and the bug-meals it pursues into the rot. Now you have to worry about bugs, spiders, potentially-lethal-to-humans-spiders, and water damage.
Collapsing Walls and Falling Ceilings
Did you know that water damage does not have to leave huge ugly stains before a wall or ceiling will collapse? The stains typical of water damage typically come with drying out, heat, and rewetting several times over, but an especially wet season will not create those stains. It will, however, still put your walls and/or ceiling in danger of major structural damage.
In fact, a wall or ceiling that is so saturated and soggy from excess water can just collapse inward on its own with little warning. Many ceilings where the water pooled just above only had to be tapped or bumped accidentally before they caved. That is seriously scary and very dangerous. If you actually spot a little trickle, it could mean that there is a pool of water just above your head, or a wall is filling with water and will cave soon.
HUGE Repair and Restoration Bills
If you are avoiding fixing the little water damage you see, you will literally pay for it. Right now, it may cost about a grand or more to fix that little trickle and paint and plaster. Later, it may cost you more than the roof to repair because of the amount of internal structural damage. Not all insurance companies will cover water damage like that either. That will leave you with a large repair bill for which you will have to pay out-of-pocket.