Suspended ceilings are ceilings of choice for many basements because they allow easy access to the wiring, plumbing and mechanical elements that run beneath the above floor joists. Basement bathrooms, however, are notoriously humid, especially if the bathroom has a shower. You can still install a suspended ceiling in this room, but you’ll benefit from using materials designed to resist moisture damage.
Suspended Ceiling Systems
Also called drop ceilings because the height of the finished ceiling is below the height of the bottom of the floor joists, a suspended ceiling features a metal grid that supports individual tiles. Typical tiles for suspended ceilings come in standard 2-by-2-foot and 2-by-4-foot sizes and some are made from lightweight acoustical materials intended to lessen sound between the basement and the main floor. You'll find tiles made from plastic, vinyl, aluminum, wood fiberboard, polystyrene and mineral fibers like perlite. The best choice for a bathroom are waterproof plastic, polystyrene or vinyl tiles that are resistant to mold and mildew.
Adapting the Ceiling
Replacing standard ceiling tiles with tiles of the same size that will withstand humidity will protect the ceiling in a basement bathroom. These moisture-resistant tiles may contain lightweight fiberglass, laminated with vinyl facing. Another popular choice for bathrooms are tiles made from extruded PVC plastic, polystyrene and vinyl because these nonporous tiles don't absorb moisture and aren't prone to rust. Because they don’t absorb moisture, they also resist mold and mildew growth. Plus, the tiles won't sag or become discolored due to moisture absorption. Since the entire bathroom is subject to moisture, replace all the bathroom tiles, not just the ones over the shower.
Reducing Humidity Levels
In addition to water-resistant tiles, vent your basement bathroom to protect drywall, wood cabinets and shelves. High humidity can condense on, and damage, porous materials. When installing a bathroom fan in a suspended ceiling, you’ll have to install blocking on the joists above the ceiling tiles to lower the fan to ceiling height. You’ll also have to install vent ducting from the fan to the exterior of the home. Otherwise, you’re just forcing the humid air out of the bathroom and into the joist area above the ceiling.
Most importantly, run the bathroom fan during showers and for about 30 minutes after the shower to remove moisture-laden air from the bathroom. You also need to leave the door to the bathroom cracked a bit during showers to keep fresh air flowing into the room for full ventilation.
Installing a new suspended ceiling will reduce the ceiling height. If you already have restricted headroom in the basement, install a grid system that fits as closely to the joists as possible. Many suspended ceiling systems require a minimum distance of about four inches from the lowest pipe or duct to the grid system.