A drop ceiling is an inexpensive way for you to add a finished lower ceiling to an area such as the basement. Drop ceiling tiles come in many styles now, too, so you don't have to settle for the standard, office-variety white. That said, there are still negative aspects of suspended ceilings, the following safety concerns first among them.
1 - Flimsy Installation
A drop ceiling is held to the true ceiling by metal wires. These supports are not very thick. Once all of the tiles are in place, they put a lot of weight on the metal supports. If you add weight to any section you run the risk of collapse. With that in mind, be cautious when adding light fixtures, insulation, ductwork, or wiring.
2 - Water Damage
Part of the reason for a suspended ceiling is to conceal the innards of the house, such as ductwork. The problem with having ducts above your ceiling tiles, though, is that they can leak. The tiles would then become soaked, rot, and fall.
3 - Faulty Wiring
One of the main problems with a drop ceiling is that it can hide faulty wiring. If there were an electrical fire in the plenum, the insulation could smolder and contain it until the smoke finally got to the room below, by which time it would be too late. For this reason, it's best to have only low-voltage wiring above a suspended ceiling.
4 - Perfect for Home Infestations
The space between the drop ceiling and fixed ceiling is often a home for rodents. Rats and mice love the airflow and moisture from the duct work, and they can bore through the insulation. This causes many problems in the long term as mice and rats often carry disease. Also, given enough time to build up, their waste can find its way to the floor below.