There are two types of drop ceiling tiles, long ceiling boards and smaller grid supported tiles. Ceiling boards are those found in mobile homes that are prone to sagging. Excessive moisture, resulting from a leaky roof or excessive humidity in bathrooms or basements can cause these ceiling boards to bow or bend under its weight. Unlike the newer styles supported individually on a grid system, ceiling boards are secured in place by gluing or nailing the tiles directly to the existing ceiling or furring strips. The only solution to repair these old tiles is to find a way to reform them while returning them to their original position. If the board is only slightly bowed, you may be lucky and try this simple remedy first. Using a spray bottle, lightly mist the tile until it is damp, and then force it back into its original position. Prop the board up with a 2-by-4 piece of wood until it has dried. If the damage was minor, the board should return to its original shape and position nicely. However, if the damage was extensive and you are unable to find a matching piece for replacement, there is another alternative to conceal the bowing boards. For this method, you will need a piece of 2-by-4 the length of the seam on the ceiling. Return the tile to its original position, place the wood over the seam of the tiles, and secure it in place with nails or screws. You may want to add more beams to cover the seams to create a unified cathedral style appearance within the room.
Chips and cracks throughout the drop ceiling tiles are a result of poor installation, shoddy removal and maintenance or careless home ownership. For homes with ceiling boards, you can try to fill any holes or small cracks with drywall putty and then perhaps prime and paint the tiles out with latex paint. For homes featuring the more common grid system, purchase a replacement tile from your local home improvement store, remove the old tile and insert the new one. You may need to use a sharp utility knife to shear off sides that do not conform to the opening well. A utility knife comes in handy for tile that no longer fit or need shaping to conform around corners or other tiles within the grid. You may have to use this tool when you have tile that do not lay flat or crooked therefore exposing seams.
Stains and discoloration are common in homes that have experienced leaks and excessive smoke damage. Kitchens and living rooms often have discolored tiles because of grease splatter and cigarette smoke. To erase these stains, apply a stain blocking latex primer with a brush or spray gun and follow up with a layer of top quality latex paint. You may want to coat the surfaces with a protective sealer to prevent the tiles from stain and smoke damage. Using this method is a great way to add a splash of color to a room as well.