If the tiles are glued directly to the ceiling, there is a chance that removing some of them also leads to the removal of plaster. Even worse, sagging tiles may pull plaster down with them, which requires a repair of the ceiling surface before once again gluing down replacement tiles. You can repair water damaged ceilings if you do it in a reasonable time after it has happened. If the board has been sagging for quite a while you may find it just won't go flat again even when screwed up. There are a number of threads quite a way back on how to prop up and fix "sagging ceilings" (I think that was the name of the thread).

Nov 25, 2016 · Home improvement and hardware stores sell SHEETROCK Brand Repair Clips – these are metal clips that are fit over the edges of the drywall hole to fasten a repair panel with screws. The SHEETROCK clips could be used in place of a wood brace and appear to be structurally sound, avoiding the sagging problem of the self-adhesive metal mesh patches. Oct 11, 2011 · Glue-Up or Staple-Up, Which Is Better? The answer to this question depends upon the tools you have available, the condition of your existing ceiling surface, and your personal preference. Most customers prefer to use glue rather than staples to install their ceiling tiles. Adhesives